first commit

lib/database/app_usage_dao.dart

@@ -0,0 +1,154 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../models/app_usage.dart';
+import 'database_helper.dart';
+
+class AppUsageDao {
+  final DatabaseHelper _dbHelper = DatabaseHelper.instance;
+
+  // Web 平台检查
+  bool get _isWeb => kIsWeb;
+
+  // 插入应用使用记录
+  Future<int> insertAppUsage(AppUsage usage) async {
+    final db = await _dbHelper.database;
+    return await db.insert('app_usage', usage.toMap());
+  }
+
+  // 批量插入
+  Future<void> batchInsertAppUsages(List<AppUsage> usages) async {
+    final db = await _dbHelper.database;
+    final batch = db.batch();
+    for (final usage in usages) {
+      batch.insert('app_usage', usage.toMap());
+    }
+    await batch.commit(noResult: true);
+  }
+
+  // 获取指定时间范围的应用使用记录
+  Future<List<AppUsage>> getAppUsages({
+    required DateTime startTime,
+    required DateTime endTime,
+  }) async {
+    if (_isWeb) return [];
+    
+    final db = await _dbHelper.database;
+    final startTimestamp = startTime.millisecondsSinceEpoch ~/ 1000;
+    final endTimestamp = endTime.millisecondsSinceEpoch ~/ 1000;
+
+    final maps = await db.query(
+      'app_usage',
+      where: 'start_time >= ? AND end_time <= ?',
+      whereArgs: [startTimestamp, endTimestamp],
+      orderBy: 'start_time DESC',
+    );
+
+    return maps.map((map) {
+      return AppUsage(
+        id: map['id'] as int?,
+        packageName: map['package_name'] as String,
+        appName: map['app_name'] as String,
+        startTime: DateTime.fromMillisecondsSinceEpoch((map['start_time'] as int) * 1000),
+        endTime: DateTime.fromMillisecondsSinceEpoch((map['end_time'] as int) * 1000),
+        duration: map['duration'] as int,
+        category: map['category'] as String,
+        projectId: map['project_id'] as int?,
+        deviceUnlockCount: map['device_unlock_count'] as int,
+        createdAt: DateTime.fromMillisecondsSinceEpoch((map['created_at'] as int) * 1000),
+        updatedAt: DateTime.fromMillisecondsSinceEpoch((map['updated_at'] as int) * 1000),
+      );
+    }).toList();
+  }
+
+  // 获取今日应用使用记录
+  Future<List<AppUsage>> getTodayAppUsages() async {
+    final now = DateTime.now();
+    final startOfDay = DateTime(now.year, now.month, now.day);
+    final endOfDay = startOfDay.add(const Duration(days: 1));
+    return await getAppUsages(startTime: startOfDay, endTime: endOfDay);
+  }
+
+  // 获取 Top N 应用
+  Future<List<AppUsage>> getTopApps({
+    required DateTime startTime,
+    required DateTime endTime,
+    int limit = 10,
+  }) async {
+    if (_isWeb) return [];
+    
+    final db = await _dbHelper.database;
+    final startTimestamp = startTime.millisecondsSinceEpoch ~/ 1000;
+    final endTimestamp = endTime.millisecondsSinceEpoch ~/ 1000;
+
+    final maps = await db.rawQuery('''
+      SELECT 
+        package_name,
+        app_name,
+        category,
+        SUM(duration) as total_duration,
+        MIN(start_time) as first_start_time,
+        MAX(end_time) as last_end_time,
+        MIN(created_at) as created_at,
+        MAX(updated_at) as updated_at
+      FROM app_usage
+      WHERE start_time >= ? AND end_time <= ?
+      GROUP BY package_name, app_name, category
+      ORDER BY total_duration DESC
+      LIMIT ?
+    ''', [startTimestamp, endTimestamp, limit]);
+
+    return maps.map((map) {
+      final firstStart = DateTime.fromMillisecondsSinceEpoch((map['first_start_time'] as int) * 1000);
+      final lastEnd = DateTime.fromMillisecondsSinceEpoch((map['last_end_time'] as int) * 1000);
+      return AppUsage(
+        packageName: map['package_name'] as String,
+        appName: map['app_name'] as String,
+        startTime: firstStart,
+        endTime: lastEnd,
+        duration: map['total_duration'] as int,
+        category: map['category'] as String,
+        createdAt: DateTime.fromMillisecondsSinceEpoch((map['created_at'] as int) * 1000),
+        updatedAt: DateTime.fromMillisecondsSinceEpoch((map['updated_at'] as int) * 1000),
+      );
+    }).toList();
+  }
+
+  // 更新应用分类
+  Future<void> updateAppUsageCategory(int id, String category) async {
+    final db = await _dbHelper.database;
+    await db.update(
+      'app_usage',
+      {
+        'category': category,
+        'updated_at': DateTime.now().millisecondsSinceEpoch ~/ 1000,
+      },
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+
+  // 删除应用使用记录
+  Future<void> deleteAppUsage(int id) async {
+    if (_isWeb) return;
+    
+    final db = await _dbHelper.database;
+    await db.delete(
+      'app_usage',
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+
+  // 删除指定日期之前的数据（用于数据清理）
+  Future<void> deleteBeforeDate(DateTime date) async {
+    if (_isWeb) return;
+    
+    final db = await _dbHelper.database;
+    final timestamp = date.millisecondsSinceEpoch ~/ 1000;
+    await db.delete(
+      'app_usage',
+      where: 'start_time < ?',
+      whereArgs: [timestamp],
+    );
+  }
+}
+

lib/database/daily_stats_dao.dart

@@ -0,0 +1,165 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../models/daily_stats.dart';
+import 'database_helper.dart';
+
+class DailyStatsDao {
+  final DatabaseHelper _dbHelper = DatabaseHelper.instance;
+
+  // Web 平台检查
+  bool get _isWeb => kIsWeb;
+
+  // 插入或更新每日统计
+  Future<void> upsertDailyStats(DailyStats stats) async {
+    final db = await _dbHelper.database;
+    final dateStr = _formatDate(stats.date);
+    final map = stats.toMap();
+    
+    final existing = await db.query(
+      'daily_stats',
+      where: 'date = ?',
+      whereArgs: [dateStr],
+    );
+
+    if (existing.isEmpty) {
+      await db.insert('daily_stats', map);
+    } else {
+      await db.update(
+        'daily_stats',
+        map,
+        where: 'date = ?',
+        whereArgs: [dateStr],
+      );
+    }
+  }
+
+  // 获取指定日期的统计
+  Future<DailyStats?> getDailyStats(DateTime date) async {
+    final db = await _dbHelper.database;
+    final dateStr = _formatDate(date);
+
+    final maps = await db.query(
+      'daily_stats',
+      where: 'date = ?',
+      whereArgs: [dateStr],
+    );
+
+    if (maps.isEmpty) return null;
+
+    return _mapToDailyStats(maps.first);
+  }
+
+  // 获取今日统计
+  Future<DailyStats?> getTodayStats() async {
+    return await getDailyStats(DateTime.now());
+  }
+
+  // 获取指定日期范围的统计
+  Future<List<DailyStats>> getStatsRange({
+    required DateTime startDate,
+    required DateTime endDate,
+  }) async {
+    if (_isWeb) return [];
+    
+    final db = await _dbHelper.database;
+    final startStr = _formatDate(startDate);
+    final endStr = _formatDate(endDate);
+
+    final maps = await db.query(
+      'daily_stats',
+      where: 'date >= ? AND date <= ?',
+      whereArgs: [startStr, endStr],
+      orderBy: 'date ASC',
+    );
+
+    return maps.map((map) => _mapToDailyStats(map)).toList();
+  }
+
+  // 获取本周统计
+  Future<List<DailyStats>> getWeekStats() async {
+    final now = DateTime.now();
+    final startOfWeek = now.subtract(Duration(days: now.weekday - 1));
+    final endOfWeek = startOfWeek.add(const Duration(days: 6));
+    return await getStatsRange(startDate: startOfWeek, endDate: endOfWeek);
+  }
+
+  // 获取本月统计
+  Future<List<DailyStats>> getMonthStats() async {
+    final now = DateTime.now();
+    final startOfMonth = DateTime(now.year, now.month, 1);
+    final endOfMonth = DateTime(now.year, now.month + 1, 0);
+    return await getStatsRange(startDate: startOfMonth, endDate: endOfMonth);
+  }
+
+  // 删除指定日期之前的数据
+  Future<void> deleteBeforeDate(DateTime date) async {
+    if (_isWeb) return;
+    
+    final db = await _dbHelper.database;
+    final dateStr = _formatDate(date);
+    await db.delete(
+      'daily_stats',
+      where: 'date < ?',
+      whereArgs: [dateStr],
+    );
+  }
+
+  // 删除指定 ID 的统计
+  Future<void> deleteDailyStats(int id) async {
+    if (_isWeb) return;
+    
+    final db = await _dbHelper.database;
+    await db.delete(
+      'daily_stats',
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+
+  String _formatDate(DateTime date) {
+    return '${date.year}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';
+  }
+
+  DailyStats _mapToDailyStats(Map<String, dynamic> map) {
+    return DailyStats(
+      id: map['id'] as int?,
+      date: DateTime.parse(map['date'] as String),
+      totalTime: map['total_time'] as int,
+      workTime: map['work_time'] as int? ?? 0,
+      studyTime: map['study_time'] as int? ?? 0,
+      entertainmentTime: map['entertainment_time'] as int? ?? 0,
+      socialTime: map['social_time'] as int? ?? 0,
+      toolTime: map['tool_time'] as int? ?? 0,
+      efficiencyScore: map['efficiency_score'] as int?,
+      focusScore: map['focus_score'] as int?,
+      appSwitchCount: map['app_switch_count'] as int? ?? 0,
+      createdAt: DateTime.fromMillisecondsSinceEpoch((map['created_at'] as int) * 1000),
+      updatedAt: DateTime.fromMillisecondsSinceEpoch((map['updated_at'] as int) * 1000),
+    );
+  }
+}
+
+// 扩展 DailyStats 模型，添加 toMap 方法
+extension DailyStatsExtension on DailyStats {
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'date': _formatDate(date),
+      'total_time': totalTime,
+      'work_time': workTime,
+      'study_time': studyTime,
+      'entertainment_time': entertainmentTime,
+      'social_time': socialTime,
+      'tool_time': toolTime,
+      'efficiency_score': efficiencyScore,
+      'focus_score': focusScore,
+      'app_switch_count': appSwitchCount,
+      'created_at': createdAt.millisecondsSinceEpoch ~/ 1000,
+      'updated_at': updatedAt.millisecondsSinceEpoch ~/ 1000,
+    };
+  }
+
+  String _formatDate(DateTime date) {
+    return '${date.year}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';
+  }
+}
+

lib/database/database_helper.dart

@@ -0,0 +1,114 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:sqflite/sqflite.dart';
+import 'package:path/path.dart';
+
+class DatabaseHelper {
+  static final DatabaseHelper instance = DatabaseHelper._init();
+  static Database? _database;
+
+  DatabaseHelper._init();
+
+  Future<Database> get database async {
+    // Web 平台不支持 sqflite
+    if (kIsWeb) {
+      throw UnsupportedError('SQLite is not supported on Web platform. Use mock data instead.');
+    }
+
+    if (_database != null) return _database!;
+    _database = await _initDB('autotime_tracker.db');
+    return _database!;
+  }
+
+  Future<Database> _initDB(String filePath) async {
+    // Web 平台不支持 sqflite
+    if (kIsWeb) {
+      throw UnsupportedError('SQLite is not supported on Web platform.');
+    }
+
+    final dbPath = await getDatabasesPath();
+    final path = join(dbPath, filePath);
+
+    return await openDatabase(
+      path,
+      version: 1,
+      onCreate: _createDB,
+    );
+  }
+
+  Future<void> _createDB(Database db, int version) async {
+    // 应用使用记录表
+    await db.execute('''
+      CREATE TABLE app_usage (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        package_name TEXT NOT NULL,
+        app_name TEXT NOT NULL,
+        start_time INTEGER NOT NULL,
+        end_time INTEGER NOT NULL,
+        duration INTEGER NOT NULL,
+        category TEXT NOT NULL,
+        project_id INTEGER,
+        device_unlock_count INTEGER DEFAULT 0,
+        created_at INTEGER NOT NULL,
+        updated_at INTEGER NOT NULL
+      )
+    ''');
+
+    // 每日统计表
+    await db.execute('''
+      CREATE TABLE daily_stats (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        date TEXT NOT NULL UNIQUE,
+        total_time INTEGER NOT NULL,
+        work_time INTEGER DEFAULT 0,
+        study_time INTEGER DEFAULT 0,
+        entertainment_time INTEGER DEFAULT 0,
+        social_time INTEGER DEFAULT 0,
+        tool_time INTEGER DEFAULT 0,
+        efficiency_score INTEGER,
+        focus_score INTEGER,
+        app_switch_count INTEGER DEFAULT 0,
+        created_at INTEGER NOT NULL,
+        updated_at INTEGER NOT NULL
+      )
+    ''');
+
+    // 应用分类表
+    await db.execute('''
+      CREATE TABLE app_category (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        package_name TEXT NOT NULL UNIQUE,
+        category TEXT NOT NULL,
+        is_custom INTEGER DEFAULT 0,
+        created_at INTEGER NOT NULL,
+        updated_at INTEGER NOT NULL
+      )
+    ''');
+
+    // 时间目标表
+    await db.execute('''
+      CREATE TABLE time_goal (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        goal_type TEXT NOT NULL,
+        category TEXT,
+        target_time INTEGER NOT NULL,
+        is_active INTEGER DEFAULT 1,
+        created_at INTEGER NOT NULL,
+        updated_at INTEGER NOT NULL
+      )
+    ''');
+
+    // 创建索引
+    await db.execute('CREATE INDEX idx_app_usage_date ON app_usage(start_time)');
+    await db.execute('CREATE INDEX idx_app_usage_category ON app_usage(category)');
+    await db.execute('CREATE INDEX idx_app_usage_package ON app_usage(package_name)');
+    await db.execute('CREATE INDEX idx_daily_stats_date ON daily_stats(date)');
+    await db.execute('CREATE INDEX idx_app_category_package ON app_category(package_name)');
+  }
+
+  // 关闭数据库
+  Future<void> close() async {
+    final db = await database;
+    await db.close();
+  }
+}
+

lib/database/time_goal_dao.dart

@@ -0,0 +1,130 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../models/time_goal.dart';
+import 'database_helper.dart';
+
+class TimeGoalDao {
+  final DatabaseHelper _dbHelper = DatabaseHelper.instance;
+
+  // Web 平台使用内存存储
+  final List<TimeGoal> _webGoals = [];
+
+  // Web 平台检查
+  bool get _isWeb => kIsWeb;
+
+  // 插入或更新时间目标
+  Future<void> upsertTimeGoal(TimeGoal goal) async {
+    if (_isWeb) {
+      // Web 平台使用内存存储
+      final index = _webGoals.indexWhere((g) => 
+        g.goalType == goal.goalType && g.category == goal.category);
+      if (index >= 0) {
+        _webGoals[index] = goal;
+      } else {
+        _webGoals.add(goal);
+      }
+      return;
+    }
+
+    final db = await _dbHelper.database;
+    final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+
+    final map = {
+      'goal_type': goal.goalType,
+      'category': goal.category,
+      'target_time': goal.targetTime,
+      'is_active': goal.isActive ? 1 : 0,
+      'created_at': now,
+      'updated_at': now,
+    };
+
+    // 检查是否已存在相同类型的目标
+    final existing = await db.query(
+      'time_goal',
+      where: 'goal_type = ? AND (category = ? OR category IS NULL)',
+      whereArgs: [
+        goal.goalType,
+        goal.category,
+      ],
+    );
+
+    if (existing.isEmpty) {
+      await db.insert('time_goal', map);
+    } else {
+      await db.update(
+        'time_goal',
+        map,
+        where: 'goal_type = ? AND (category = ? OR category IS NULL)',
+        whereArgs: [
+          goal.goalType,
+          goal.category,
+        ],
+      );
+    }
+  }
+
+  // 获取所有激活的目标
+  Future<List<TimeGoal>> getActiveGoals() async {
+    if (_isWeb) {
+      return _webGoals.where((g) => g.isActive).toList();
+    }
+
+    final db = await _dbHelper.database;
+    final maps = await db.query(
+      'time_goal',
+      where: 'is_active = 1',
+      orderBy: 'goal_type, category',
+    );
+
+    return maps.map((map) => TimeGoal.fromMap(map)).toList();
+  }
+
+  // 获取所有目标（包括非激活的）
+  Future<List<TimeGoal>> getAllGoals() async {
+    if (_isWeb) {
+      return List<TimeGoal>.from(_webGoals);
+    }
+
+    final db = await _dbHelper.database;
+    final maps = await db.query(
+      'time_goal',
+      orderBy: 'goal_type, category',
+    );
+
+    return maps.map((map) => TimeGoal.fromMap(map)).toList();
+  }
+
+  // 获取指定类型的目标
+  Future<TimeGoal?> getGoal(String goalType, {String? category}) async {
+    final db = await _dbHelper.database;
+    final maps = await db.query(
+      'time_goal',
+      where: 'goal_type = ? AND (category = ? OR category IS NULL) AND is_active = 1',
+      whereArgs: [goalType, category],
+    );
+
+    if (maps.isEmpty) return null;
+    return TimeGoal.fromMap(maps.first);
+  }
+
+  // 删除目标
+  Future<void> deleteGoal(int id) async {
+    final db = await _dbHelper.database;
+    await db.delete(
+      'time_goal',
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+
+  // 停用目标
+  Future<void> deactivateGoal(int id) async {
+    final db = await _dbHelper.database;
+    await db.update(
+      'time_goal',
+      {'is_active': 0, 'updated_at': DateTime.now().millisecondsSinceEpoch ~/ 1000},
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+}
+

lib/main.dart

@@ -0,0 +1,84 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:intl/date_symbol_data_local.dart';
+import 'screens/home_screen.dart';
+import 'screens/permission_screen.dart';
+import 'theme/app_theme.dart';
+import 'providers/time_tracking_provider.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  
+  // 初始化日期格式化本地化数据
+  await initializeDateFormatting('zh_CN', null);
+  
+  runApp(
+    const ProviderScope(
+      child: AutoTimeTrackerApp(),
+    ),
+  );
+}
+
+class AutoTimeTrackerApp extends StatelessWidget {
+  const AutoTimeTrackerApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'AutoTime Tracker',
+      debugShowCheckedModeBanner: false,
+      theme: AppTheme.lightTheme,
+      darkTheme: AppTheme.darkTheme,
+      themeMode: ThemeMode.system,
+      home: const PermissionCheckScreen(),
+    );
+  }
+}
+
+/// 权限检查屏幕 - 检查权限后决定显示哪个页面
+class PermissionCheckScreen extends ConsumerWidget {
+  const PermissionCheckScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Web 平台直接显示主界面（使用测试数据）
+    if (kIsWeb) {
+      return const HomeScreen();
+    }
+
+    final permissionStatus = ref.watch(permissionStatusProvider);
+
+    return permissionStatus.when(
+      data: (hasPermission) {
+        if (hasPermission) {
+          return const HomeScreen();
+        } else {
+          return const PermissionScreen();
+        }
+      },
+      loading: () => const Scaffold(
+        body: Center(child: CircularProgressIndicator()),
+      ),
+      error: (error, stack) => Scaffold(
+        body: Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              const Icon(Icons.error_outline, size: 48, color: Colors.red),
+              const SizedBox(height: 16),
+              Text('检查权限时出错: $error'),
+              const SizedBox(height: 16),
+              ElevatedButton(
+                onPressed: () {
+                  ref.invalidate(permissionStatusProvider);
+                },
+                child: const Text('重试'),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/models/app_usage.dart

@@ -0,0 +1,70 @@
+class AppUsage {
+  final int? id;
+  final String packageName;
+  final String appName;
+  final DateTime startTime;
+  final DateTime endTime;
+  final int duration; // 秒
+  final String category;
+  final int? projectId;
+  final int deviceUnlockCount;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+
+  AppUsage({
+    this.id,
+    required this.packageName,
+    required this.appName,
+    required this.startTime,
+    required this.endTime,
+    required this.duration,
+    required this.category,
+    this.projectId,
+    this.deviceUnlockCount = 0,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'package_name': packageName,
+      'app_name': appName,
+      'start_time': startTime.millisecondsSinceEpoch ~/ 1000,
+      'end_time': endTime.millisecondsSinceEpoch ~/ 1000,
+      'duration': duration,
+      'category': category,
+      'project_id': projectId,
+      'device_unlock_count': deviceUnlockCount,
+      'created_at': createdAt.millisecondsSinceEpoch ~/ 1000,
+      'updated_at': updatedAt.millisecondsSinceEpoch ~/ 1000,
+    };
+  }
+
+  factory AppUsage.fromMap(Map<String, dynamic> map) {
+    return AppUsage(
+      id: map['id'],
+      packageName: map['package_name'],
+      appName: map['app_name'],
+      startTime: DateTime.fromMillisecondsSinceEpoch(map['start_time'] * 1000),
+      endTime: DateTime.fromMillisecondsSinceEpoch(map['end_time'] * 1000),
+      duration: map['duration'],
+      category: map['category'],
+      projectId: map['project_id'],
+      deviceUnlockCount: map['device_unlock_count'] ?? 0,
+      createdAt: DateTime.fromMillisecondsSinceEpoch(map['created_at'] * 1000),
+      updatedAt: DateTime.fromMillisecondsSinceEpoch(map['updated_at'] * 1000),
+    );
+  }
+
+  // 格式化时长
+  String get formattedDuration {
+    final hours = duration ~/ 3600;
+    final minutes = (duration % 3600) ~/ 60;
+    if (hours > 0) {
+      return '${hours}h ${minutes}m';
+    }
+    return '${minutes}m';
+  }
+}
+

lib/models/daily_stats.dart

@@ -0,0 +1,64 @@
+import 'package:flutter/material.dart';
+
+class DailyStats {
+  final int? id;
+  final DateTime date;
+  final int totalTime; // 秒
+  final int workTime;
+  final int studyTime;
+  final int entertainmentTime;
+  final int socialTime;
+  final int toolTime;
+  final int? efficiencyScore;
+  final int? focusScore;
+  final int appSwitchCount;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+
+  DailyStats({
+    this.id,
+    required this.date,
+    required this.totalTime,
+    this.workTime = 0,
+    this.studyTime = 0,
+    this.entertainmentTime = 0,
+    this.socialTime = 0,
+    this.toolTime = 0,
+    this.efficiencyScore,
+    this.focusScore,
+    this.appSwitchCount = 0,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  Map<String, int> get categoryTime => {
+    'work': workTime,
+    'study': studyTime,
+    'entertainment': entertainmentTime,
+    'social': socialTime,
+    'tool': toolTime,
+  };
+
+  // 格式化总时长
+  String get formattedTotalTime {
+    final hours = totalTime ~/ 3600;
+    final minutes = (totalTime % 3600) ~/ 60;
+    if (hours > 0) {
+      return '${hours}h ${minutes}m';
+    }
+    return '${minutes}m';
+  }
+
+  // 获取效率评分颜色
+  Color get efficiencyColor {
+    final score = efficiencyScore ?? 0;
+    if (score >= 80) {
+      return const Color(0xFF10B981); // Green
+    } else if (score >= 50) {
+      return const Color(0xFFF59E0B); // Orange
+    } else {
+      return const Color(0xFFEF4444); // Red
+    }
+  }
+}
+

lib/models/time_goal.dart

@@ -0,0 +1,54 @@
+class TimeGoal {
+  final int? id;
+  final String goalType; // 'daily_total' 或 'daily_category'
+  final String? category; // 如果是分类目标，指定分类
+  final int targetTime; // 目标时长（秒）
+  final bool isActive;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+
+  TimeGoal({
+    this.id,
+    required this.goalType,
+    this.category,
+    required this.targetTime,
+    this.isActive = true,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'goal_type': goalType,
+      'category': category,
+      'target_time': targetTime,
+      'is_active': isActive ? 1 : 0,
+      'created_at': createdAt.millisecondsSinceEpoch ~/ 1000,
+      'updated_at': updatedAt.millisecondsSinceEpoch ~/ 1000,
+    };
+  }
+
+  factory TimeGoal.fromMap(Map<String, dynamic> map) {
+    return TimeGoal(
+      id: map['id'] as int?,
+      goalType: map['goal_type'] as String,
+      category: map['category'] as String?,
+      targetTime: map['target_time'] as int,
+      isActive: (map['is_active'] as int) == 1,
+      createdAt: DateTime.fromMillisecondsSinceEpoch((map['created_at'] as int) * 1000),
+      updatedAt: DateTime.fromMillisecondsSinceEpoch((map['updated_at'] as int) * 1000),
+    );
+  }
+
+  // 格式化目标时长
+  String get formattedTargetTime {
+    final hours = targetTime ~/ 3600;
+    final minutes = (targetTime % 3600) ~/ 60;
+    if (hours > 0) {
+      return '${hours}小时${minutes}分钟';
+    }
+    return '${minutes}分钟';
+  }
+}
+

lib/providers/background_sync_provider.dart

@@ -0,0 +1,20 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../services/background_sync_service.dart';
+
+// BackgroundSyncService Provider
+final backgroundSyncServiceProvider = Provider<BackgroundSyncService>((ref) {
+  final service = BackgroundSyncService();
+  
+  // 当 Provider 被销毁时，停止服务
+  ref.onDispose(() {
+    service.stop();
+  });
+  
+  return service;
+});
+
+// 后台同步状态 Provider
+final backgroundSyncStatusProvider = StateProvider<bool>((ref) {
+  return false;
+});
+

lib/providers/statistics_provider.dart

@@ -0,0 +1,54 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../models/daily_stats.dart';
+import '../models/app_usage.dart';
+import '../services/statistics_service.dart';
+
+// StatisticsService Provider
+final statisticsServiceProvider = Provider<StatisticsService>((ref) {
+  return StatisticsService();
+});
+
+// 今日统计 Provider
+final todayStatsProvider = FutureProvider<DailyStats>((ref) async {
+  final service = ref.read(statisticsServiceProvider);
+  return await service.getTodayStats();
+});
+
+// 本周统计 Provider
+final weekStatsProvider = FutureProvider<List<DailyStats>>((ref) async {
+  final service = ref.read(statisticsServiceProvider);
+  return await service.getWeekStats();
+});
+
+// 本月统计 Provider
+final monthStatsProvider = FutureProvider<List<DailyStats>>((ref) async {
+  final service = ref.read(statisticsServiceProvider);
+  return await service.getMonthStats();
+});
+
+// 今日统计列表 Provider（用于日视图，只返回今日数据）
+final todayStatsListProvider = FutureProvider<List<DailyStats>>((ref) async {
+  final service = ref.read(statisticsServiceProvider);
+  final todayStats = await service.getTodayStats();
+  return [todayStats];
+});
+
+// 今日 Top 应用 Provider
+final todayTopAppsProvider = FutureProvider<List<AppUsage>>((ref) async {
+  final service = ref.read(statisticsServiceProvider);
+  final now = DateTime.now();
+  final startOfDay = DateTime(now.year, now.month, now.day);
+  final endOfDay = startOfDay.add(const Duration(days: 1));
+  return await service.getTopApps(
+    startTime: startOfDay,
+    endTime: endOfDay,
+    limit: 5,
+  );
+});
+
+// 刷新今日统计 Provider
+final refreshTodayStatsProvider = FutureProvider.family<DailyStats, void>((ref, _) async {
+  final service = ref.read(statisticsServiceProvider);
+  return await service.refreshTodayStats();
+});
+

lib/providers/time_tracking_provider.dart

@@ -0,0 +1,20 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../services/time_tracking_service.dart';
+
+// TimeTrackingService Provider
+final timeTrackingServiceProvider = Provider<TimeTrackingService>((ref) {
+  return TimeTrackingService();
+});
+
+// 权限状态 Provider
+final permissionStatusProvider = FutureProvider<bool>((ref) async {
+  final service = ref.read(timeTrackingServiceProvider);
+  return await service.hasPermission();
+});
+
+// 后台追踪状态 Provider
+final backgroundTrackingStatusProvider = FutureProvider<bool>((ref) async {
+  final service = ref.read(timeTrackingServiceProvider);
+  return await service.isBackgroundTrackingActive();
+});
+

lib/screens/about_screen.dart

@@ -0,0 +1,293 @@
+import 'package:flutter/material.dart';
+import '../theme/app_theme.dart';
+
+class AboutScreen extends StatelessWidget {
+  const AboutScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('关于'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(24),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.center,
+          children: [
+            // 应用图标和名称
+            Container(
+              width: 80,
+              height: 80,
+              decoration: BoxDecoration(
+                color: AppTheme.primaryColor,
+                borderRadius: BorderRadius.circular(20),
+              ),
+              child: const Icon(
+                Icons.timer,
+                color: Colors.white,
+                size: 48,
+              ),
+            ),
+            const SizedBox(height: 16),
+            Text(
+              'AutoTime Tracker',
+              style: theme.textTheme.headlineMedium?.copyWith(
+                fontWeight: FontWeight.bold,
+              ),
+            ),
+            const SizedBox(height: 8),
+            Text(
+              '版本 1.0.0',
+              style: theme.textTheme.bodyMedium?.copyWith(
+                color: theme.colorScheme.onSurface.withOpacity(0.6),
+              ),
+            ),
+            const SizedBox(height: 32),
+
+            // 应用描述
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      '关于应用',
+                      style: theme.textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 12),
+                    Text(
+                      'AutoTime Tracker 是一款自动时间追踪与效率分析工具。'
+                      '它可以帮助您自动追踪应用使用情况，分析时间分配，'
+                      '并提供效率评分和个性化建议。',
+                      style: theme.textTheme.bodyMedium,
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 功能特点
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      '核心功能',
+                      style: theme.textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 12),
+                    _buildFeatureItem(theme, Icons.auto_awesome, '自动追踪', '无需手动操作，自动记录应用使用时间'),
+                    _buildFeatureItem(theme, Icons.category, '智能分类', '自动将应用分类为工作、学习、娱乐等'),
+                    _buildFeatureItem(theme, Icons.insights, '数据分析', '提供详细的统计分析和效率评分'),
+                    _buildFeatureItem(theme, Icons.flag, '目标设定', '设置时间目标，追踪完成情况'),
+                    _buildFeatureItem(theme, Icons.file_download, '数据导出', '导出 CSV 和统计报告'),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 链接
+            Card(
+              child: Column(
+                children: [
+                  _buildLinkItem(
+                    context,
+                    theme,
+                    Icons.description,
+                    '隐私政策',
+                    '查看我们的隐私政策',
+                    () {
+                      // TODO: 打开隐私政策页面
+                      _showComingSoon(context);
+                    },
+                  ),
+                  const Divider(height: 1),
+                  _buildLinkItem(
+                    context,
+                    theme,
+                    Icons.feedback,
+                    '反馈建议',
+                    '帮助我们改进应用',
+                    () {
+                      _launchEmail(context);
+                    },
+                  ),
+                  const Divider(height: 1),
+                  _buildLinkItem(
+                    context,
+                    theme,
+                    Icons.star,
+                    '评价应用',
+                    '在应用商店给我们评分',
+                    () {
+                      // TODO: 打开应用商店
+                      _showComingSoon(context);
+                    },
+                  ),
+                  const Divider(height: 1),
+                  _buildLinkItem(
+                    context,
+                    theme,
+                    Icons.code,
+                    '开源许可',
+                    'MIT License',
+                    () {
+                      _showLicense(context, theme);
+                    },
+                  ),
+                ],
+              ),
+            ),
+            const SizedBox(height: 24),
+
+            // 版权信息
+            Text(
+              '© 2024 AutoTime Tracker',
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onSurface.withOpacity(0.5),
+              ),
+            ),
+            const SizedBox(height: 8),
+            Text(
+              'Made with ❤️ using Flutter',
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onSurface.withOpacity(0.5),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildFeatureItem(ThemeData theme, IconData icon, String title, String description) {
+    return Padding(
+      padding: const EdgeInsets.only(bottom: 12),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Icon(icon, color: AppTheme.primaryColor, size: 24),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  title,
+                  style: theme.textTheme.bodyLarge?.copyWith(
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+                const SizedBox(height: 4),
+                Text(
+                  description,
+                  style: theme.textTheme.bodySmall?.copyWith(
+                    color: theme.colorScheme.onSurface.withOpacity(0.6),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildLinkItem(
+    BuildContext context,
+    ThemeData theme,
+    IconData icon,
+    String title,
+    String subtitle,
+    VoidCallback onTap,
+  ) {
+    return ListTile(
+      leading: Icon(icon, color: AppTheme.primaryColor),
+      title: Text(
+        title,
+        style: theme.textTheme.bodyLarge?.copyWith(
+          fontWeight: FontWeight.w500,
+        ),
+      ),
+      subtitle: Text(
+        subtitle,
+        style: theme.textTheme.bodySmall?.copyWith(
+          color: theme.colorScheme.onSurface.withOpacity(0.6),
+        ),
+      ),
+      trailing: const Icon(Icons.chevron_right),
+      onTap: onTap,
+    );
+  }
+
+  void _launchEmail(BuildContext context) {
+    // 显示反馈邮箱
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('反馈建议'),
+        content: const Text(
+          '欢迎通过以下方式联系我们：\n\n'
+          '邮箱：support@autotime-tracker.com\n\n'
+          '我们非常重视您的反馈和建议！',
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: const Text('确定'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _showComingSoon(BuildContext context) {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('即将推出'),
+        content: const Text('此功能正在开发中，敬请期待！'),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: const Text('确定'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _showLicense(BuildContext context, ThemeData theme) {
+    showLicensePage(
+      context: context,
+      applicationName: 'AutoTime Tracker',
+      applicationVersion: '1.0.0',
+      applicationIcon: Container(
+        width: 64,
+        height: 64,
+        decoration: BoxDecoration(
+          color: AppTheme.primaryColor,
+          borderRadius: BorderRadius.circular(16),
+        ),
+        child: const Icon(
+          Icons.timer,
+          color: Colors.white,
+          size: 32,
+        ),
+      ),
+    );
+  }
+}
+

lib/screens/appearance_settings_screen.dart

@@ -0,0 +1,263 @@
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import '../theme/app_theme.dart';
+
+class AppearanceSettingsScreen extends StatefulWidget {
+  const AppearanceSettingsScreen({super.key});
+
+  @override
+  State<AppearanceSettingsScreen> createState() => _AppearanceSettingsScreenState();
+}
+
+class _AppearanceSettingsScreenState extends State<AppearanceSettingsScreen> {
+  ThemeMode _themeMode = ThemeMode.system;
+  double _fontSize = 1.0; // 1.0 = 正常，0.8 = 小，1.2 = 大
+
+  @override
+  void initState() {
+    super.initState();
+    _loadSettings();
+  }
+
+  Future<void> _loadSettings() async {
+    final prefs = await SharedPreferences.getInstance();
+    final themeModeIndex = prefs.getInt('theme_mode') ?? 0;
+    setState(() {
+      _themeMode = ThemeMode.values[themeModeIndex];
+      _fontSize = prefs.getDouble('font_size') ?? 1.0;
+    });
+  }
+
+  Future<void> _saveSettings() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setInt('theme_mode', _themeMode.index);
+    await prefs.setDouble('font_size', _fontSize);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('外观设置'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // 主题模式
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.palette, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '主题模式',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    RadioListTile<ThemeMode>(
+                      title: const Text('跟随系统'),
+                      subtitle: const Text('根据系统设置自动切换'),
+                      value: ThemeMode.system,
+                      groupValue: _themeMode,
+                      onChanged: (value) {
+                        if (value != null) {
+                          setState(() {
+                            _themeMode = value;
+                          });
+                          _saveSettings();
+                          // 通知应用更新主题
+                          // 注意：这需要重启应用或使用 Provider 来管理主题
+                        }
+                      },
+                    ),
+                    RadioListTile<ThemeMode>(
+                      title: const Text('浅色模式'),
+                      subtitle: const Text('始终使用浅色主题'),
+                      value: ThemeMode.light,
+                      groupValue: _themeMode,
+                      onChanged: (value) {
+                        if (value != null) {
+                          setState(() {
+                            _themeMode = value;
+                          });
+                          _saveSettings();
+                        }
+                      },
+                    ),
+                    RadioListTile<ThemeMode>(
+                      title: const Text('深色模式'),
+                      subtitle: const Text('始终使用深色主题'),
+                      value: ThemeMode.dark,
+                      groupValue: _themeMode,
+                      onChanged: (value) {
+                        if (value != null) {
+                          setState(() {
+                            _themeMode = value;
+                          });
+                          _saveSettings();
+                        }
+                      },
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 字体大小
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.text_fields, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '字体大小',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    Text(
+                      '当前大小: ${_getFontSizeLabel(_fontSize)}',
+                      style: theme.textTheme.bodyMedium,
+                    ),
+                    const SizedBox(height: 16),
+                    Slider(
+                      value: _fontSize,
+                      min: 0.8,
+                      max: 1.2,
+                      divisions: 4,
+                      label: _getFontSizeLabel(_fontSize),
+                      onChanged: (value) {
+                        setState(() {
+                          _fontSize = value;
+                        });
+                        _saveSettings();
+                      },
+                    ),
+                    Row(
+                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                      children: [
+                        Text(
+                          '小',
+                          style: theme.textTheme.bodySmall?.copyWith(
+                            fontSize: 12 * _fontSize,
+                          ),
+                        ),
+                        Text(
+                          '正常',
+                          style: theme.textTheme.bodyMedium?.copyWith(
+                            fontSize: 14 * _fontSize,
+                          ),
+                        ),
+                        Text(
+                          '大',
+                          style: theme.textTheme.bodyLarge?.copyWith(
+                            fontSize: 16 * _fontSize,
+                          ),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 图表样式（占位，未来功能）
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.bar_chart, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '图表样式',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    ListTile(
+                      title: const Text('图表颜色主题'),
+                      subtitle: const Text('默认主题'),
+                      trailing: const Icon(Icons.chevron_right),
+                      onTap: () {
+                        ScaffoldMessenger.of(context).showSnackBar(
+                          const SnackBar(
+                            content: Text('此功能正在开发中'),
+                          ),
+                        );
+                      },
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 24),
+
+            // 说明
+            Card(
+              color: AppTheme.infoColor.withOpacity(0.1),
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Row(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Icon(Icons.info_outline, color: AppTheme.infoColor),
+                    const SizedBox(width: 12),
+                    Expanded(
+                      child: Text(
+                        '主题模式更改需要重启应用才能生效。字体大小更改会立即生效。',
+                        style: theme.textTheme.bodySmall?.copyWith(
+                          color: theme.colorScheme.onSurface.withOpacity(0.7),
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  String _getFontSizeLabel(double size) {
+    if (size <= 0.9) {
+      return '小';
+    } else if (size <= 1.1) {
+      return '正常';
+    } else {
+      return '大';
+    }
+  }
+}
+

lib/screens/category_management_screen.dart

@@ -0,0 +1,290 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../theme/app_theme.dart';
+import '../services/category_service.dart';
+import '../database/app_usage_dao.dart';
+import '../widgets/empty_state_widget.dart';
+import '../widgets/error_state_widget.dart';
+
+class CategoryManagementScreen extends ConsumerStatefulWidget {
+  const CategoryManagementScreen({super.key});
+
+  @override
+  ConsumerState<CategoryManagementScreen> createState() => _CategoryManagementScreenState();
+}
+
+class _CategoryManagementScreenState extends ConsumerState<CategoryManagementScreen> {
+  final CategoryService _categoryService = CategoryService();
+  final AppUsageDao _appUsageDao = AppUsageDao();
+  final TextEditingController _searchController = TextEditingController();
+  String _searchQuery = '';
+
+  // 可用分类列表
+  final List<String> _availableCategories = ['work', 'study', 'entertainment', 'social', 'tool', 'other'];
+
+  @override
+  void dispose() {
+    _searchController.dispose();
+    super.dispose();
+  }
+
+  Future<List<AppCategoryItem>> _loadAppCategories() async {
+    // 获取所有应用使用记录（最近使用的）
+    // 如果数据库为空，返回空列表（Web 平台会返回空列表）
+    final now = DateTime.now();
+    final startOfWeek = now.subtract(const Duration(days: 7));
+    final appUsages = await _appUsageDao.getAppUsages(
+      startTime: startOfWeek,
+      endTime: now,
+    );
+    
+    // 如果没有数据，返回空列表
+    if (appUsages.isEmpty) {
+      return [];
+    }
+
+    // 获取自定义分类
+    final customCategories = await _categoryService.getAllCustomCategories();
+
+    // 去重并创建列表
+    final packageMap = <String, AppCategoryItem>{};
+    for (final usage in appUsages) {
+      if (!packageMap.containsKey(usage.packageName)) {
+        final currentCategory = customCategories[usage.packageName] ??
+            CategoryService.defaultCategories[usage.packageName] ??
+            'other';
+        
+        packageMap[usage.packageName] = AppCategoryItem(
+          packageName: usage.packageName,
+          appName: usage.appName,
+          category: currentCategory,
+          isCustom: customCategories.containsKey(usage.packageName),
+        );
+      }
+    }
+
+    return packageMap.values.toList()
+      ..sort((a, b) => a.appName.compareTo(b.appName));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('应用分类'),
+      ),
+      body: Column(
+        children: [
+          // 搜索框
+          Padding(
+            padding: const EdgeInsets.all(16),
+            child: TextField(
+              controller: _searchController,
+              decoration: InputDecoration(
+                hintText: '搜索应用...',
+                prefixIcon: const Icon(Icons.search),
+                suffixIcon: _searchQuery.isNotEmpty
+                    ? IconButton(
+                        icon: const Icon(Icons.clear),
+                        onPressed: () {
+                          _searchController.clear();
+                          setState(() {
+                            _searchQuery = '';
+                          });
+                        },
+                      )
+                    : null,
+                border: OutlineInputBorder(
+                  borderRadius: BorderRadius.circular(12),
+                ),
+              ),
+              onChanged: (value) {
+                setState(() {
+                  _searchQuery = value;
+                });
+              },
+            ),
+          ),
+
+          // 应用列表
+          Expanded(
+            child: FutureBuilder<List<AppCategoryItem>>(
+              future: _loadAppCategories(),
+              builder: (context, snapshot) {
+                if (snapshot.connectionState == ConnectionState.waiting) {
+                  return const Center(child: CircularProgressIndicator());
+                }
+
+                if (snapshot.hasError) {
+                  return ErrorStateWidget.dataLoad(
+                    message: _getErrorMessage(snapshot.error!),
+                    onRetry: () {
+                      setState(() {});
+                    },
+                  );
+                }
+
+                final items = snapshot.data ?? [];
+                final filteredItems = _searchQuery.isEmpty
+                    ? items
+                    : items.where((item) {
+                        return item.appName.toLowerCase().contains(_searchQuery.toLowerCase()) ||
+                               item.packageName.toLowerCase().contains(_searchQuery.toLowerCase());
+                      }).toList();
+
+                if (filteredItems.isEmpty) {
+                  if (_searchQuery.isEmpty) {
+                    return EmptyStateWidget.noApps(
+                      onAction: () {
+                        setState(() {});
+                      },
+                    );
+                  } else {
+                    return EmptyStateWidget.noSearchResults(query: _searchQuery);
+                  }
+                }
+
+                return ListView.builder(
+                  padding: const EdgeInsets.symmetric(horizontal: 16),
+                  itemCount: filteredItems.length,
+                  itemBuilder: (context, index) {
+                    final item = filteredItems[index];
+                    return _buildAppCategoryItem(context, theme, item);
+                  },
+                );
+              },
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildAppCategoryItem(
+    BuildContext context,
+    ThemeData theme,
+    AppCategoryItem item,
+  ) {
+    return Card(
+      margin: const EdgeInsets.only(bottom: 8),
+      child: ListTile(
+        leading: Container(
+          width: 40,
+          height: 40,
+          decoration: BoxDecoration(
+            color: AppTheme.getCategoryColor(item.category).withOpacity(0.1),
+            borderRadius: BorderRadius.circular(8),
+          ),
+          child: Icon(
+            Icons.phone_android,
+            color: AppTheme.getCategoryColor(item.category),
+          ),
+        ),
+        title: Text(
+          item.appName,
+          style: theme.textTheme.bodyLarge?.copyWith(
+            fontWeight: FontWeight.w500,
+          ),
+        ),
+        subtitle: Text(
+          item.packageName,
+          style: theme.textTheme.bodySmall?.copyWith(
+            color: theme.colorScheme.onSurface.withOpacity(0.6),
+          ),
+        ),
+        trailing: PopupMenuButton<String>(
+          icon: Row(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Container(
+                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+                decoration: BoxDecoration(
+                  color: AppTheme.getCategoryColor(item.category).withOpacity(0.1),
+                  borderRadius: BorderRadius.circular(12),
+                ),
+                child: Text(
+                  AppTheme.getCategoryName(item.category),
+                  style: TextStyle(
+                    color: AppTheme.getCategoryColor(item.category),
+                    fontSize: 12,
+                    fontWeight: FontWeight.w500,
+                  ),
+                ),
+              ),
+              const SizedBox(width: 8),
+              const Icon(Icons.arrow_drop_down),
+            ],
+          ),
+          onSelected: (String category) async {
+            await _categoryService.setCategory(item.packageName, category);
+            setState(() {});
+            
+            if (context.mounted) {
+              ScaffoldMessenger.of(context).showSnackBar(
+                SnackBar(
+                  content: Text('已将 ${item.appName} 分类为 ${AppTheme.getCategoryName(category)}'),
+                  duration: const Duration(seconds: 2),
+                ),
+              );
+            }
+          },
+          itemBuilder: (BuildContext context) {
+            return _availableCategories.map((category) {
+              return PopupMenuItem<String>(
+                value: category,
+                child: Row(
+                  children: [
+                    if (item.category == category)
+                      const Icon(Icons.check, size: 20, color: AppTheme.primaryColor)
+                    else
+                      const SizedBox(width: 20),
+                    const SizedBox(width: 8),
+                    Container(
+                      width: 12,
+                      height: 12,
+                      decoration: BoxDecoration(
+                        color: AppTheme.getCategoryColor(category),
+                        shape: BoxShape.circle,
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    Text(AppTheme.getCategoryName(category)),
+                  ],
+                ),
+              );
+            }).toList();
+          },
+        ),
+      ),
+    );
+  }
+
+  String _getErrorMessage(Object error) {
+    final errorString = error.toString().toLowerCase();
+    if (errorString.contains('permission') || errorString.contains('权限')) {
+      return '需要授予应用使用权限';
+    } else if (errorString.contains('network') || errorString.contains('网络')) {
+      return '网络连接失败，请检查网络';
+    } else if (errorString.contains('database') || errorString.contains('数据库')) {
+      return '数据库操作失败';
+    }
+    return '加载失败，请稍后重试';
+  }
+}
+
+class AppCategoryItem {
+  final String packageName;
+  final String appName;
+  final String category;
+  final bool isCustom;
+
+  AppCategoryItem({
+    required this.packageName,
+    required this.appName,
+    required this.category,
+    required this.isCustom,
+  });
+}
+

lib/screens/data_privacy_screen.dart

@@ -0,0 +1,414 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../theme/app_theme.dart';
+import '../database/app_usage_dao.dart';
+import '../database/daily_stats_dao.dart';
+
+class DataPrivacyScreen extends StatefulWidget {
+  const DataPrivacyScreen({super.key});
+
+  @override
+  State<DataPrivacyScreen> createState() => _DataPrivacyScreenState();
+}
+
+class _DataPrivacyScreenState extends State<DataPrivacyScreen> {
+  final AppUsageDao _appUsageDao = AppUsageDao();
+  final DailyStatsDao _dailyStatsDao = DailyStatsDao();
+  bool _isDeleting = false;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('数据与隐私'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // 隐私说明
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.security, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '隐私保护',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    _buildPrivacyItem(
+                      theme,
+                      Icons.storage,
+                      '本地存储',
+                      '所有数据仅存储在您的设备本地，不会上传到任何服务器。',
+                    ),
+                    _buildPrivacyItem(
+                      theme,
+                      Icons.lock,
+                      '数据加密',
+                      '敏感数据在存储时进行加密处理，确保数据安全。',
+                    ),
+                    _buildPrivacyItem(
+                      theme,
+                      Icons.visibility_off,
+                      '隐私保护',
+                      '我们不会收集您的个人信息，也不会追踪您的具体操作内容。',
+                    ),
+                    _buildPrivacyItem(
+                      theme,
+                      Icons.delete_forever,
+                      '完全控制',
+                      '您可以随时删除所有数据，完全掌控您的隐私。',
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 数据管理
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      '数据管理',
+                      style: theme.textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 16),
+                    _buildDataAction(
+                      context,
+                      theme,
+                      Icons.delete_outline,
+                      '删除旧数据',
+                      '删除 30 天前的数据',
+                      Colors.orange,
+                      () => _showDeleteOldDataDialog(context),
+                    ),
+                    const SizedBox(height: 12),
+                    _buildDataAction(
+                      context,
+                      theme,
+                      Icons.delete_forever,
+                      '清空所有数据',
+                      '删除所有使用记录和统计数据',
+                      Colors.red,
+                      () => _showDeleteAllDataDialog(context),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 数据使用说明
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      '数据使用说明',
+                      style: theme.textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 12),
+                    Text(
+                      '• 应用使用数据仅用于统计和分析\n'
+                      '• 数据不会离开您的设备\n'
+                      '• 不会与第三方分享任何数据\n'
+                      '• 不会用于广告或营销目的\n'
+                      '• 您可以随时导出或删除数据',
+                      style: theme.textTheme.bodyMedium,
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildPrivacyItem(ThemeData theme, IconData icon, String title, String description) {
+    return Padding(
+      padding: const EdgeInsets.only(bottom: 16),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Icon(icon, color: AppTheme.primaryColor, size: 24),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  title,
+                  style: theme.textTheme.bodyLarge?.copyWith(
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+                const SizedBox(height: 4),
+                Text(
+                  description,
+                  style: theme.textTheme.bodySmall?.copyWith(
+                    color: theme.colorScheme.onSurface.withOpacity(0.6),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildDataAction(
+    BuildContext context,
+    ThemeData theme,
+    IconData icon,
+    String title,
+    String subtitle,
+    Color color,
+    VoidCallback onTap,
+  ) {
+    return InkWell(
+      onTap: _isDeleting ? null : onTap,
+      borderRadius: BorderRadius.circular(8),
+      child: Container(
+        padding: const EdgeInsets.all(12),
+        decoration: BoxDecoration(
+          border: Border.all(color: color.withOpacity(0.3)),
+          borderRadius: BorderRadius.circular(8),
+        ),
+        child: Row(
+          children: [
+            Icon(icon, color: color),
+            const SizedBox(width: 12),
+            Expanded(
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Text(
+                    title,
+                    style: theme.textTheme.bodyLarge?.copyWith(
+                      fontWeight: FontWeight.w600,
+                      color: color,
+                    ),
+                  ),
+                  const SizedBox(height: 4),
+                  Text(
+                    subtitle,
+                    style: theme.textTheme.bodySmall?.copyWith(
+                      color: theme.colorScheme.onSurface.withOpacity(0.6),
+                    ),
+                  ),
+                ],
+              ),
+            ),
+            if (_isDeleting)
+              const SizedBox(
+                width: 20,
+                height: 20,
+                child: CircularProgressIndicator(strokeWidth: 2),
+              )
+            else
+              const Icon(Icons.chevron_right),
+          ],
+        ),
+      ),
+    );
+  }
+
+  void _showDeleteOldDataDialog(BuildContext context) {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('删除旧数据'),
+        content: const Text('确定要删除 30 天前的所有数据吗？此操作不可恢复。'),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: const Text('取消'),
+          ),
+          ElevatedButton(
+            onPressed: () async {
+              Navigator.of(context).pop();
+              await _deleteOldData(context);
+            },
+            style: ElevatedButton.styleFrom(
+              backgroundColor: Colors.orange,
+            ),
+            child: const Text('删除'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _showDeleteAllDataDialog(BuildContext context) {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('清空所有数据'),
+        content: const Text(
+          '确定要删除所有使用记录和统计数据吗？\n\n'
+          '此操作将：\n'
+          '• 删除所有应用使用记录\n'
+          '• 删除所有统计数据\n'
+          '• 删除所有分类设置\n'
+          '• 删除所有目标设置\n\n'
+          '此操作不可恢复！',
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: const Text('取消'),
+          ),
+          ElevatedButton(
+            onPressed: () async {
+              Navigator.of(context).pop();
+              await _deleteAllData(context);
+            },
+            style: ElevatedButton.styleFrom(
+              backgroundColor: Colors.red,
+            ),
+            child: const Text('确认删除'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Future<void> _deleteOldData(BuildContext context) async {
+    if (kIsWeb) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(
+          content: Text('Web 平台不支持数据删除功能'),
+          backgroundColor: AppTheme.warningColor,
+        ),
+      );
+      return;
+    }
+
+    setState(() {
+      _isDeleting = true;
+    });
+
+    try {
+      final thirtyDaysAgo = DateTime.now().subtract(const Duration(days: 30));
+      
+      await _appUsageDao.deleteBeforeDate(thirtyDaysAgo);
+      await _dailyStatsDao.deleteBeforeDate(thirtyDaysAgo);
+
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          const SnackBar(
+            content: Text('已删除 30 天前的数据'),
+            backgroundColor: AppTheme.successColor,
+          ),
+        );
+      }
+    } catch (e) {
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('删除失败: $e'),
+            backgroundColor: AppTheme.errorColor,
+          ),
+        );
+      }
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isDeleting = false;
+        });
+      }
+    }
+  }
+
+  Future<void> _deleteAllData(BuildContext context) async {
+    if (kIsWeb) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(
+          content: Text('Web 平台不支持数据删除功能'),
+          backgroundColor: AppTheme.warningColor,
+        ),
+      );
+      return;
+    }
+
+    setState(() {
+      _isDeleting = true;
+    });
+
+    try {
+      // 删除所有应用使用记录
+      final allUsages = await _appUsageDao.getAppUsages(
+        startTime: DateTime(2000),
+        endTime: DateTime.now(),
+      );
+      for (final usage in allUsages) {
+        if (usage.id != null) {
+          await _appUsageDao.deleteAppUsage(usage.id!);
+        }
+      }
+
+      // 删除所有统计数据
+      final allStats = await _dailyStatsDao.getStatsRange(
+        startDate: DateTime(2000),
+        endDate: DateTime.now(),
+      );
+      for (final stat in allStats) {
+        if (stat.id != null) {
+          await _dailyStatsDao.deleteDailyStats(stat.id!);
+        }
+      }
+
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          const SnackBar(
+            content: Text('已清空所有数据'),
+            backgroundColor: AppTheme.successColor,
+          ),
+        );
+      }
+    } catch (e) {
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('删除失败: $e'),
+            backgroundColor: AppTheme.errorColor,
+          ),
+        );
+      }
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isDeleting = false;
+        });
+      }
+    }
+  }
+}
+

lib/screens/export_data_screen.dart

@@ -0,0 +1,403 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../theme/app_theme.dart';
+import '../services/export_service.dart';
+
+// Web 平台需要的导入
+import 'dart:html' as html show Blob, Url, AnchorElement;
+
+class ExportDataScreen extends StatefulWidget {
+  const ExportDataScreen({super.key});
+
+  @override
+  State<ExportDataScreen> createState() => _ExportDataScreenState();
+}
+
+class _ExportDataScreenState extends State<ExportDataScreen> {
+  final ExportService _exportService = ExportService();
+  DateTime _startDate = DateTime.now().subtract(const Duration(days: 7));
+  DateTime _endDate = DateTime.now();
+  bool _isExporting = false;
+
+  Future<void> _exportCSV() async {
+    setState(() {
+      _isExporting = true;
+    });
+
+    try {
+      final csvData = await _exportService.exportToCSV(
+        startDate: _startDate,
+        endDate: _endDate,
+      );
+
+      if (csvData.isEmpty || csvData.trim().isEmpty) {
+        if (mounted) {
+          ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(
+              content: Text('所选日期范围内没有数据可导出'),
+              backgroundColor: AppTheme.warningColor,
+            ),
+          );
+        }
+        return;
+      }
+
+      if (kIsWeb) {
+        // Web 平台：下载文件
+        final blob = html.Blob([csvData], 'text/csv');
+        final url = html.Url.createObjectUrlFromBlob(blob);
+        html.AnchorElement(href: url)
+          ..setAttribute('download', 'autotime_export_${DateTime.now().millisecondsSinceEpoch}.csv')
+          ..click();
+        html.Url.revokeObjectUrl(url);
+      } else {
+        // 移动端：复制到剪贴板
+        await Clipboard.setData(ClipboardData(text: csvData));
+      }
+
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(kIsWeb ? '文件已下载' : '数据已复制到剪贴板'),
+            backgroundColor: AppTheme.successColor,
+          ),
+        );
+      }
+    } catch (e) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(_getExportErrorMessage(e)),
+            backgroundColor: AppTheme.errorColor,
+            action: SnackBarAction(
+              label: '重试',
+              textColor: Colors.white,
+              onPressed: _exportReport,
+            ),
+          ),
+        );
+      }
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isExporting = false;
+        });
+      }
+    }
+  }
+
+  Future<void> _exportReport() async {
+    setState(() {
+      _isExporting = true;
+    });
+
+    try {
+      final report = await _exportService.exportStatsReport(
+        startDate: _startDate,
+        endDate: _endDate,
+      );
+
+      if (report.isEmpty || report.trim().isEmpty) {
+        if (mounted) {
+          ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(
+              content: Text('所选日期范围内没有统计数据可导出'),
+              backgroundColor: AppTheme.warningColor,
+            ),
+          );
+        }
+        return;
+      }
+
+      if (kIsWeb) {
+        // Web 平台：下载文件
+        final blob = html.Blob([report], 'text/plain');
+        final url = html.Url.createObjectUrlFromBlob(blob);
+        html.AnchorElement(href: url)
+          ..setAttribute('download', 'autotime_report_${DateTime.now().millisecondsSinceEpoch}.txt')
+          ..click();
+        html.Url.revokeObjectUrl(url);
+      } else {
+        // 移动端：复制到剪贴板
+        await Clipboard.setData(ClipboardData(text: report));
+      }
+
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(kIsWeb ? '文件已下载' : '报告已复制到剪贴板'),
+            backgroundColor: AppTheme.successColor,
+          ),
+        );
+      }
+    } catch (e) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(_getExportErrorMessage(e)),
+            backgroundColor: AppTheme.errorColor,
+            action: SnackBarAction(
+              label: '重试',
+              textColor: Colors.white,
+              onPressed: _exportReport,
+            ),
+          ),
+        );
+      }
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isExporting = false;
+        });
+      }
+    }
+  }
+
+  Future<void> _exportTodayReport() async {
+    setState(() {
+      _isExporting = true;
+    });
+
+    try {
+      final report = await _exportService.exportTodayReport();
+
+      if (report.isEmpty || report.trim().isEmpty) {
+        if (mounted) {
+          ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(
+              content: Text('今日暂无数据可导出'),
+              backgroundColor: AppTheme.warningColor,
+            ),
+          );
+        }
+        return;
+      }
+
+      if (kIsWeb) {
+        // Web 平台：下载文件
+        final blob = html.Blob([report], 'text/plain');
+        final url = html.Url.createObjectUrlFromBlob(blob);
+        html.AnchorElement(href: url)
+          ..setAttribute('download', 'autotime_today_${DateTime.now().millisecondsSinceEpoch}.txt')
+          ..click();
+        html.Url.revokeObjectUrl(url);
+      } else {
+        // 移动端：复制到剪贴板
+        await Clipboard.setData(ClipboardData(text: report));
+      }
+
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(kIsWeb ? '文件已下载' : '今日报告已复制到剪贴板'),
+            backgroundColor: AppTheme.successColor,
+          ),
+        );
+      }
+    } catch (e) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(_getExportErrorMessage(e)),
+            backgroundColor: AppTheme.errorColor,
+            action: SnackBarAction(
+              label: '重试',
+              textColor: Colors.white,
+              onPressed: _exportTodayReport,
+            ),
+          ),
+        );
+      }
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isExporting = false;
+        });
+      }
+    }
+  }
+
+  Future<void> _selectDateRange() async {
+    final DateTimeRange? picked = await showDateRangePicker(
+      context: context,
+      firstDate: DateTime(2020),
+      lastDate: DateTime.now(),
+      initialDateRange: DateTimeRange(start: _startDate, end: _endDate),
+    );
+
+    if (picked != null) {
+      setState(() {
+        _startDate = picked.start;
+        _endDate = picked.end;
+      });
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('数据导出'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            // 日期范围选择
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      '选择日期范围',
+                      style: theme.textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 16),
+                    Row(
+                      children: [
+                        Expanded(
+                          child: OutlinedButton.icon(
+                            onPressed: _selectDateRange,
+                            icon: const Icon(Icons.calendar_today),
+                            label: Text(
+                              '${_startDate.toString().split(' ')[0]} 至 ${_endDate.toString().split(' ')[0]}',
+                            ),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 导出选项
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      '导出选项',
+                      style: theme.textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 16),
+                    
+                    // CSV 导出
+                    _buildExportOption(
+                      theme,
+                      icon: Icons.table_chart,
+                      title: '导出 CSV 数据',
+                      subtitle: '导出原始应用使用数据（CSV 格式）',
+                      onTap: _exportCSV,
+                    ),
+                    const SizedBox(height: 12),
+                    
+                    // 统计报告
+                    _buildExportOption(
+                      theme,
+                      icon: Icons.description,
+                      title: '导出统计报告',
+                      subtitle: '导出时间范围内的统计报告（文本格式）',
+                      onTap: _exportReport,
+                    ),
+                    const SizedBox(height: 12),
+                    
+                    // 今日报告
+                    _buildExportOption(
+                      theme,
+                      icon: Icons.today,
+                      title: '导出今日报告',
+                      subtitle: '导出今日的详细统计报告',
+                      onTap: _exportTodayReport,
+                    ),
+                  ],
+                ),
+              ),
+            ),
+
+            if (_isExporting)
+              const Padding(
+                padding: EdgeInsets.all(16),
+                child: Center(child: CircularProgressIndicator()),
+              ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildExportOption(
+    ThemeData theme, {
+    required IconData icon,
+    required String title,
+    required String subtitle,
+    required VoidCallback onTap,
+  }) {
+    return InkWell(
+      onTap: _isExporting ? null : onTap,
+      borderRadius: BorderRadius.circular(8),
+      child: Container(
+        padding: const EdgeInsets.all(12),
+        decoration: BoxDecoration(
+          border: Border.all(
+            color: theme.colorScheme.onSurface.withOpacity(0.1),
+          ),
+          borderRadius: BorderRadius.circular(8),
+        ),
+        child: Row(
+          children: [
+            Icon(icon, color: AppTheme.primaryColor),
+            const SizedBox(width: 12),
+            Expanded(
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Text(
+                    title,
+                    style: theme.textTheme.bodyLarge?.copyWith(
+                      fontWeight: FontWeight.w600,
+                    ),
+                  ),
+                  const SizedBox(height: 4),
+                  Text(
+                    subtitle,
+                    style: theme.textTheme.bodySmall?.copyWith(
+                      color: theme.colorScheme.onSurface.withOpacity(0.6),
+                    ),
+                  ),
+                ],
+              ),
+            ),
+            const Icon(Icons.chevron_right),
+          ],
+        ),
+      ),
+    );
+  }
+
+  String _getExportErrorMessage(Object error) {
+    final errorString = error.toString().toLowerCase();
+    if (errorString.contains('permission') || errorString.contains('权限')) {
+      return '需要授予应用使用权限';
+    } else if (errorString.contains('database') || errorString.contains('数据库')) {
+      return '数据库操作失败，请稍后重试';
+    } else if (errorString.contains('file') || errorString.contains('文件')) {
+      return '文件操作失败，请检查存储权限';
+    }
+    return '导出失败，请稍后重试';
+  }
+}
+

lib/screens/goal_setting_screen.dart

@@ -0,0 +1,494 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../theme/app_theme.dart';
+import '../models/time_goal.dart';
+import '../database/time_goal_dao.dart';
+
+class GoalSettingScreen extends ConsumerStatefulWidget {
+  const GoalSettingScreen({super.key});
+
+  @override
+  ConsumerState<GoalSettingScreen> createState() => _GoalSettingScreenState();
+}
+
+class _GoalSettingScreenState extends ConsumerState<GoalSettingScreen> {
+  final TimeGoalDao _goalDao = TimeGoalDao();
+
+  TimeGoal? _dailyTotalGoal;
+  final Map<String, TimeGoal?> _categoryGoals = {};
+
+  @override
+  void initState() {
+    super.initState();
+    _loadGoals();
+  }
+
+  Future<void> _loadGoals() async {
+    // 获取所有目标（包括非激活的），以便正确显示开关状态
+    final allGoals = await _goalDao.getAllGoals();
+    
+    setState(() {
+      // 查找每日总时长目标
+      final dailyTotal = allGoals.firstWhere(
+        (g) => g.goalType == 'daily_total',
+        orElse: () => TimeGoal(
+          goalType: 'daily_total',
+          targetTime: 28800, // 默认 8 小时
+          isActive: _dailyTotalGoal?.isActive ?? true, // 保持当前状态
+          createdAt: _dailyTotalGoal?.createdAt ?? DateTime.now(),
+          updatedAt: DateTime.now(),
+        ),
+      );
+      
+      // 如果找到的目标有 ID，使用它；否则保持当前 ID（如果有）
+      _dailyTotalGoal = TimeGoal(
+        id: dailyTotal.id ?? _dailyTotalGoal?.id,
+        goalType: dailyTotal.goalType,
+        targetTime: dailyTotal.targetTime,
+        isActive: dailyTotal.isActive,
+        createdAt: dailyTotal.createdAt,
+        updatedAt: dailyTotal.updatedAt,
+      );
+
+      final categories = ['work', 'study', 'entertainment', 'social', 'tool'];
+      for (final category in categories) {
+        _categoryGoals[category] = allGoals.firstWhere(
+          (g) => g.goalType == 'daily_category' && g.category == category,
+          orElse: () => TimeGoal(
+            goalType: 'daily_category',
+            category: category,
+            targetTime: 0,
+            isActive: false,
+            createdAt: DateTime.now(),
+            updatedAt: DateTime.now(),
+          ),
+        );
+      }
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('时间目标'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // 每日总时长目标
+            _buildDailyTotalGoalCard(theme),
+            const SizedBox(height: 16),
+
+            // 分类时间限制
+            _buildCategoryGoalsCard(theme),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildDailyTotalGoalCard(ThemeData theme) {
+    return Card(
+      child: Padding(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Row(
+              children: [
+                Icon(Icons.timer, color: AppTheme.primaryColor),
+                const SizedBox(width: 8),
+                Text(
+                  '每日总时长目标',
+                  style: theme.textTheme.titleMedium?.copyWith(
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+              ],
+            ),
+            const SizedBox(height: 16),
+            if (_dailyTotalGoal != null) ...[
+              Row(
+                children: [
+                  Expanded(
+                    child: Text(
+                      _dailyTotalGoal!.formattedTargetTime,
+                      style: theme.textTheme.headlineSmall?.copyWith(
+                        fontWeight: FontWeight.bold,
+                        color: AppTheme.primaryColor,
+                      ),
+                    ),
+                  ),
+                  Switch(
+                    value: _dailyTotalGoal!.isActive,
+                    onChanged: (value) async {
+                      // 先更新本地状态，立即显示变化
+                      setState(() {
+                        _dailyTotalGoal = TimeGoal(
+                          id: _dailyTotalGoal!.id,
+                          goalType: _dailyTotalGoal!.goalType,
+                          targetTime: _dailyTotalGoal!.targetTime,
+                          isActive: value,
+                          createdAt: _dailyTotalGoal!.createdAt,
+                          updatedAt: DateTime.now(),
+                        );
+                      });
+                      
+                      // 然后保存到数据库
+                      await _goalDao.upsertTimeGoal(_dailyTotalGoal!);
+                      // 重新加载以确保数据同步
+                      await _loadGoals();
+                    },
+                  ),
+                ],
+              ),
+              const SizedBox(height: 16),
+              _buildTimePicker(
+                theme,
+                '设置目标时长',
+                _dailyTotalGoal!.targetTime,
+                (hours, minutes) async {
+                  final targetTime = hours * 3600 + minutes * 60;
+                  final updatedGoal = TimeGoal(
+                    id: _dailyTotalGoal!.id,
+                    goalType: 'daily_total',
+                    targetTime: targetTime,
+                    isActive: _dailyTotalGoal!.isActive,
+                    createdAt: _dailyTotalGoal!.createdAt,
+                    updatedAt: DateTime.now(),
+                  );
+                  await _goalDao.upsertTimeGoal(updatedGoal);
+                  await _loadGoals();
+                },
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildCategoryGoalsCard(ThemeData theme) {
+    return Card(
+      child: Padding(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Row(
+              children: [
+                Icon(Icons.category, color: AppTheme.primaryColor),
+                const SizedBox(width: 8),
+                Text(
+                  '分类时间限制',
+                  style: theme.textTheme.titleMedium?.copyWith(
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+              ],
+            ),
+            const SizedBox(height: 16),
+            ...['work', 'study', 'entertainment', 'social', 'tool'].map((category) {
+              final goal = _categoryGoals[category];
+              return _buildCategoryGoalItem(theme, category, goal);
+            }),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildCategoryGoalItem(
+    ThemeData theme,
+    String category,
+    TimeGoal? goal,
+  ) {
+    final isActive = goal?.isActive ?? false;
+    final targetTime = goal?.targetTime ?? 0;
+
+    return Padding(
+      padding: const EdgeInsets.only(bottom: 12),
+      child: Row(
+        children: [
+          Container(
+            width: 12,
+            height: 12,
+            decoration: BoxDecoration(
+              color: AppTheme.getCategoryColor(category),
+              shape: BoxShape.circle,
+            ),
+          ),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Text(
+              AppTheme.getCategoryName(category),
+              style: theme.textTheme.bodyLarge,
+            ),
+          ),
+          Text(
+            targetTime > 0 ? _formatTime(targetTime) : '未设置',
+            style: theme.textTheme.bodyMedium?.copyWith(
+              color: isActive ? AppTheme.primaryColor : theme.colorScheme.onSurface.withOpacity(0.5),
+              fontWeight: isActive ? FontWeight.w600 : FontWeight.normal,
+            ),
+          ),
+          const SizedBox(width: 12),
+          Switch(
+            value: isActive,
+            onChanged: (value) async {
+              if (value && targetTime == 0) {
+                // 如果启用但未设置时间，先设置默认值
+                final defaultGoal = TimeGoal(
+                  id: goal?.id,
+                  goalType: 'daily_category',
+                  category: category,
+                  targetTime: 7200, // 默认 2 小时
+                  isActive: true,
+                  createdAt: goal?.createdAt ?? DateTime.now(),
+                  updatedAt: DateTime.now(),
+                );
+                await _goalDao.upsertTimeGoal(defaultGoal);
+              } else {
+                final updatedGoal = TimeGoal(
+                  id: goal?.id,
+                  goalType: 'daily_category',
+                  category: category,
+                  targetTime: targetTime,
+                  isActive: value,
+                  createdAt: goal?.createdAt ?? DateTime.now(),
+                  updatedAt: DateTime.now(),
+                );
+                await _goalDao.upsertTimeGoal(updatedGoal);
+              }
+              await _loadGoals();
+            },
+          ),
+          IconButton(
+            icon: const Icon(Icons.edit),
+            onPressed: () {
+              _showCategoryGoalDialog(theme, category, goal);
+            },
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _showCategoryGoalDialog(ThemeData theme, String category, TimeGoal? goal) {
+    final currentTime = goal?.targetTime ?? 0;
+    final hours = currentTime ~/ 3600;
+    final minutes = (currentTime % 3600) ~/ 60;
+
+    showDialog(
+      context: context,
+      builder: (context) => _TimePickerDialog(
+        title: '设置 ${AppTheme.getCategoryName(category)} 时间限制',
+        initialHours: hours,
+        initialMinutes: minutes,
+        onSave: (hours, minutes) async {
+          final targetTime = hours * 3600 + minutes * 60;
+          final updatedGoal = TimeGoal(
+            id: goal?.id,
+            goalType: 'daily_category',
+            category: category,
+            targetTime: targetTime,
+            isActive: true,
+            createdAt: goal?.createdAt ?? DateTime.now(),
+            updatedAt: DateTime.now(),
+          );
+          await _goalDao.upsertTimeGoal(updatedGoal);
+          await _loadGoals();
+        },
+      ),
+    );
+  }
+
+  Widget _buildTimePicker(
+    ThemeData theme,
+    String title,
+    int currentTime,
+    Future<void> Function(int hours, int minutes) onSave,
+  ) {
+    final hours = currentTime ~/ 3600;
+    final minutes = (currentTime % 3600) ~/ 60;
+
+    return ElevatedButton.icon(
+      onPressed: () {
+        showDialog(
+          context: context,
+          builder: (context) => _TimePickerDialog(
+            title: title,
+            initialHours: hours,
+            initialMinutes: minutes,
+            onSave: onSave,
+          ),
+        );
+      },
+      icon: const Icon(Icons.access_time),
+      label: Text('${hours}小时 ${minutes}分钟'),
+      style: ElevatedButton.styleFrom(
+        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+      ),
+    );
+  }
+
+  String _formatTime(int seconds) {
+    final hours = seconds ~/ 3600;
+    final minutes = (seconds % 3600) ~/ 60;
+    if (hours > 0) {
+      return '${hours}h ${minutes}m';
+    }
+    return '${minutes}m';
+  }
+}
+
+class _TimePickerDialog extends StatefulWidget {
+  final String title;
+  final int initialHours;
+  final int initialMinutes;
+  final Future<void> Function(int hours, int minutes) onSave;
+
+  const _TimePickerDialog({
+    required this.title,
+    required this.initialHours,
+    required this.initialMinutes,
+    required this.onSave,
+  });
+
+  @override
+  State<_TimePickerDialog> createState() => _TimePickerDialogState();
+}
+
+class _TimePickerDialogState extends State<_TimePickerDialog> {
+  late int _hours;
+  late int _minutes;
+
+  @override
+  void initState() {
+    super.initState();
+    _hours = widget.initialHours;
+    _minutes = widget.initialMinutes;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return AlertDialog(
+      title: Text(widget.title),
+      content: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Row(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              // 小时选择
+              Column(
+                children: [
+                  Text('小时', style: theme.textTheme.bodySmall),
+                  const SizedBox(height: 8),
+                  Row(
+                    children: [
+                      IconButton(
+                        icon: const Icon(Icons.remove_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            if (_hours > 0) _hours--;
+                          });
+                        },
+                      ),
+                      SizedBox(
+                        width: 60,
+                        child: Text(
+                          '$_hours',
+                          textAlign: TextAlign.center,
+                          style: theme.textTheme.headlineMedium,
+                        ),
+                      ),
+                      IconButton(
+                        icon: const Icon(Icons.add_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            if (_hours < 24) _hours++;
+                          });
+                        },
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+              const SizedBox(width: 24),
+              // 分钟选择
+              Column(
+                children: [
+                  Text('分钟', style: theme.textTheme.bodySmall),
+                  const SizedBox(height: 8),
+                  Row(
+                    children: [
+                      IconButton(
+                        icon: const Icon(Icons.remove_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            if (_minutes > 0) {
+                              _minutes -= 15;
+                              if (_minutes < 0) _minutes = 0;
+                            }
+                          });
+                        },
+                      ),
+                      SizedBox(
+                        width: 60,
+                        child: Text(
+                          '$_minutes',
+                          textAlign: TextAlign.center,
+                          style: theme.textTheme.headlineMedium,
+                        ),
+                      ),
+                      IconButton(
+                        icon: const Icon(Icons.add_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            _minutes += 15;
+                            if (_minutes >= 60) {
+                              _hours++;
+                              _minutes = 0;
+                            }
+                            if (_hours >= 24) {
+                              _hours = 23;
+                              _minutes = 59;
+                            }
+                          });
+                        },
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ],
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.of(context).pop(),
+          child: const Text('取消'),
+        ),
+        ElevatedButton(
+          onPressed: () async {
+            await widget.onSave(_hours, _minutes);
+            if (mounted) {
+              Navigator.of(context).pop();
+            }
+          },
+          child: const Text('保存'),
+        ),
+      ],
+    );
+  }
+}
+

lib/screens/home_screen.dart

@@ -0,0 +1,73 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'today_screen.dart';
+import 'stats_screen.dart';
+import 'settings_screen.dart';
+import '../providers/background_sync_provider.dart';
+
+class HomeScreen extends ConsumerStatefulWidget {
+  const HomeScreen({super.key});
+
+  @override
+  ConsumerState<HomeScreen> createState() => _HomeScreenState();
+}
+
+class _HomeScreenState extends ConsumerState<HomeScreen> {
+  int _currentIndex = 0;
+
+  final List<Widget> _screens = [
+    const TodayScreen(),
+    const StatsScreen(),
+    const SettingsScreen(),
+  ];
+
+  @override
+  void initState() {
+    super.initState();
+    // Web 平台不启动后台同步服务
+    if (!kIsWeb) {
+      // 启动后台同步服务
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        final syncService = ref.read(backgroundSyncServiceProvider);
+        syncService.start();
+      });
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: IndexedStack(
+        index: _currentIndex,
+        children: _screens,
+      ),
+      bottomNavigationBar: NavigationBar(
+        selectedIndex: _currentIndex,
+        onDestinationSelected: (index) {
+          setState(() {
+            _currentIndex = index;
+          });
+        },
+        destinations: const [
+          NavigationDestination(
+            icon: Icon(Icons.today_outlined),
+            selectedIcon: Icon(Icons.today),
+            label: 'Today',
+          ),
+          NavigationDestination(
+            icon: Icon(Icons.bar_chart_outlined),
+            selectedIcon: Icon(Icons.bar_chart),
+            label: 'Stats',
+          ),
+          NavigationDestination(
+            icon: Icon(Icons.settings_outlined),
+            selectedIcon: Icon(Icons.settings),
+            label: 'Settings',
+          ),
+        ],
+      ),
+    );
+  }
+}
+

lib/screens/notification_settings_screen.dart

@@ -0,0 +1,252 @@
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import '../theme/app_theme.dart';
+import '../widgets/custom_time_picker_dialog.dart';
+
+class NotificationSettingsScreen extends StatefulWidget {
+  const NotificationSettingsScreen({super.key});
+
+  @override
+  State<NotificationSettingsScreen> createState() => _NotificationSettingsScreenState();
+}
+
+class _NotificationSettingsScreenState extends State<NotificationSettingsScreen> {
+  bool _goalReminderEnabled = true;
+  bool _dailyReportEnabled = true;
+  bool _weeklyReportEnabled = false;
+  TimeOfDay _goalReminderTime = const TimeOfDay(hour: 20, minute: 0);
+  TimeOfDay _dailyReportTime = const TimeOfDay(hour: 22, minute: 0);
+
+  @override
+  void initState() {
+    super.initState();
+    _loadSettings();
+  }
+
+  Future<void> _loadSettings() async {
+    final prefs = await SharedPreferences.getInstance();
+    setState(() {
+      _goalReminderEnabled = prefs.getBool('goal_reminder_enabled') ?? true;
+      _dailyReportEnabled = prefs.getBool('daily_report_enabled') ?? true;
+      _weeklyReportEnabled = prefs.getBool('weekly_report_enabled') ?? false;
+      
+      final goalReminderHour = prefs.getInt('goal_reminder_hour') ?? 20;
+      final goalReminderMinute = prefs.getInt('goal_reminder_minute') ?? 0;
+      _goalReminderTime = TimeOfDay(hour: goalReminderHour, minute: goalReminderMinute);
+      
+      final dailyReportHour = prefs.getInt('daily_report_hour') ?? 22;
+      final dailyReportMinute = prefs.getInt('daily_report_minute') ?? 0;
+      _dailyReportTime = TimeOfDay(hour: dailyReportHour, minute: dailyReportMinute);
+    });
+  }
+
+  Future<void> _saveSettings() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool('goal_reminder_enabled', _goalReminderEnabled);
+    await prefs.setBool('daily_report_enabled', _dailyReportEnabled);
+    await prefs.setBool('weekly_report_enabled', _weeklyReportEnabled);
+    await prefs.setInt('goal_reminder_hour', _goalReminderTime.hour);
+    await prefs.setInt('goal_reminder_minute', _goalReminderTime.minute);
+    await prefs.setInt('daily_report_hour', _dailyReportTime.hour);
+    await prefs.setInt('daily_report_minute', _dailyReportTime.minute);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('通知设置'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // 目标提醒
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.flag, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '目标提醒',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    SwitchListTile(
+                      title: const Text('启用目标提醒'),
+                      subtitle: const Text('当接近或超过时间目标时提醒'),
+                      value: _goalReminderEnabled,
+                      onChanged: (value) {
+                        setState(() {
+                          _goalReminderEnabled = value;
+                        });
+                        _saveSettings();
+                      },
+                    ),
+                    if (_goalReminderEnabled) ...[
+                      const SizedBox(height: 8),
+                      ListTile(
+                        title: const Text('提醒时间'),
+                        subtitle: Text(
+                          '${_goalReminderTime.hour.toString().padLeft(2, '0')}:${_goalReminderTime.minute.toString().padLeft(2, '0')}',
+                        ),
+                        trailing: const Icon(Icons.chevron_right),
+                        onTap: () async {
+                          final TimeOfDay? picked = await CustomTimePickerDialog.show(
+                            context: context,
+                            title: '选择提醒时间',
+                            initialTime: _goalReminderTime,
+                          );
+                          if (picked != null) {
+                            setState(() {
+                              _goalReminderTime = picked;
+                            });
+                            await _saveSettings();
+                          }
+                        },
+                      ),
+                    ],
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 每日报告
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.today, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '每日报告',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    SwitchListTile(
+                      title: const Text('启用每日报告'),
+                      subtitle: const Text('每天发送使用时间摘要'),
+                      value: _dailyReportEnabled,
+                      onChanged: (value) {
+                        setState(() {
+                          _dailyReportEnabled = value;
+                        });
+                        _saveSettings();
+                      },
+                    ),
+                    if (_dailyReportEnabled) ...[
+                      const SizedBox(height: 8),
+                      ListTile(
+                        title: const Text('报告时间'),
+                        subtitle: Text(
+                          '${_dailyReportTime.hour.toString().padLeft(2, '0')}:${_dailyReportTime.minute.toString().padLeft(2, '0')}',
+                        ),
+                        trailing: const Icon(Icons.chevron_right),
+                        onTap: () async {
+                          final TimeOfDay? picked = await CustomTimePickerDialog.show(
+                            context: context,
+                            title: '选择报告时间',
+                            initialTime: _dailyReportTime,
+                          );
+                          if (picked != null) {
+                            setState(() {
+                              _dailyReportTime = picked;
+                            });
+                            await _saveSettings();
+                          }
+                        },
+                      ),
+                    ],
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 16),
+
+            // 每周报告
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Icon(Icons.calendar_view_week, color: AppTheme.primaryColor),
+                        const SizedBox(width: 8),
+                        Text(
+                          '每周报告',
+                          style: theme.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 16),
+                    SwitchListTile(
+                      title: const Text('启用每周报告'),
+                      subtitle: const Text('每周一发送周报摘要'),
+                      value: _weeklyReportEnabled,
+                      onChanged: (value) {
+                        setState(() {
+                          _weeklyReportEnabled = value;
+                        });
+                        _saveSettings();
+                      },
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 24),
+
+            // 说明
+            Card(
+              color: AppTheme.infoColor.withOpacity(0.1),
+              child: Padding(
+                padding: const EdgeInsets.all(16),
+                child: Row(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Icon(Icons.info_outline, color: AppTheme.infoColor),
+                    const SizedBox(width: 12),
+                    Expanded(
+                      child: Text(
+                        '通知功能需要系统通知权限。请在系统设置中授予通知权限。',
+                        style: theme.textTheme.bodySmall?.copyWith(
+                          color: theme.colorScheme.onSurface.withOpacity(0.7),
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+

lib/screens/permission_screen.dart

@@ -0,0 +1,229 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter/foundation.dart' show kIsWeb, defaultTargetPlatform;
+import 'package:flutter/foundation.dart' show TargetPlatform;
+import '../providers/time_tracking_provider.dart';
+import '../widgets/error_state_widget.dart';
+
+class PermissionScreen extends ConsumerWidget {
+  const PermissionScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final permissionStatus = ref.watch(permissionStatusProvider);
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('权限设置'),
+      ),
+      body: SingleChildScrollView(
+        padding: const EdgeInsets.all(24),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            // 图标
+            Icon(
+              Icons.security,
+              size: 80,
+              color: theme.colorScheme.primary,
+            ),
+            const SizedBox(height: 24),
+
+            // 标题
+            Text(
+              '我们需要访问您的应用使用数据',
+              style: theme.textTheme.headlineSmall?.copyWith(
+                fontWeight: FontWeight.bold,
+              ),
+              textAlign: TextAlign.center,
+            ),
+            const SizedBox(height: 16),
+
+            // 说明
+            Text(
+              _getPermissionDescription(),
+              style: theme.textTheme.bodyLarge?.copyWith(
+                color: theme.colorScheme.onSurface.withOpacity(0.7),
+              ),
+              textAlign: TextAlign.center,
+            ),
+            const SizedBox(height: 32),
+
+            // 权限状态
+            permissionStatus.when(
+              data: (hasPermission) {
+                if (hasPermission) {
+                  return _buildPermissionGranted(context, theme);
+                } else {
+                  return _buildPermissionRequest(context, ref, theme);
+                }
+              },
+              loading: () => const Center(child: CircularProgressIndicator()),
+              error: (error, stack) => ErrorStateWidget.generic(
+                message: '检查权限时出错，请重试',
+                onRetry: () {
+                  ref.invalidate(permissionStatusProvider);
+                },
+              ),
+            ),
+
+            const SizedBox(height: 32),
+
+            // 隐私说明
+            _buildPrivacyInfo(theme),
+          ],
+        ),
+      ),
+    );
+  }
+
+  String _getPermissionDescription() {
+    if (kIsWeb) {
+      return 'Web 平台暂不支持时间追踪功能。\n\n'
+          '请使用 iOS 或 Android 应用。';
+    } else if (defaultTargetPlatform == TargetPlatform.iOS) {
+      return '这样我们才能自动追踪您的应用使用情况，无需手动操作。\n\n'
+          '• 完全自动化，无需手动操作\n'
+          '• 数据仅存储在本地\n'
+          '• 不会上传到服务器';
+    } else {
+      return '这样我们才能自动追踪您的应用使用情况，无需手动操作。\n\n'
+          '• 完全自动化，无需手动操作\n'
+          '• 数据仅存储在本地\n'
+          '• 不会上传到服务器';
+    }
+  }
+
+  Widget _buildPermissionRequest(BuildContext context, WidgetRef ref, ThemeData theme) {
+    return Column(
+      children: [
+        Container(
+          padding: const EdgeInsets.all(16),
+          decoration: BoxDecoration(
+            color: theme.colorScheme.errorContainer,
+            borderRadius: BorderRadius.circular(12),
+          ),
+          child: Row(
+            children: [
+              Icon(
+                Icons.warning_amber_rounded,
+                color: theme.colorScheme.error,
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Text(
+                  '权限未授予',
+                  style: theme.textTheme.bodyLarge?.copyWith(
+                    color: theme.colorScheme.error,
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+              ),
+            ],
+          ),
+        ),
+        const SizedBox(height: 24),
+        ElevatedButton(
+          onPressed: () async {
+            final service = ref.read(timeTrackingServiceProvider);
+            final granted = await service.requestPermission();
+            
+            if (granted) {
+              ref.invalidate(permissionStatusProvider);
+              if (context.mounted) {
+                ScaffoldMessenger.of(context).showSnackBar(
+                  const SnackBar(content: Text('权限已授予')),
+                );
+              }
+            } else {
+              if (context.mounted) {
+                ScaffoldMessenger.of(context).showSnackBar(
+                  const SnackBar(content: Text('权限授予失败，请前往设置中手动开启')),
+                );
+              }
+            }
+          },
+          style: ElevatedButton.styleFrom(
+            padding: const EdgeInsets.symmetric(vertical: 16),
+            shape: RoundedRectangleBorder(
+              borderRadius: BorderRadius.circular(12),
+            ),
+          ),
+          child: const Text(
+            '去设置',
+            style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
+          ),
+        ),
+        const SizedBox(height: 12),
+        TextButton(
+          onPressed: () {
+            Navigator.of(context).pop();
+          },
+          child: const Text('稍后再说'),
+        ),
+      ],
+    );
+  }
+
+  Widget _buildPermissionGranted(BuildContext context, ThemeData theme) {
+    return Container(
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.colorScheme.primaryContainer,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Row(
+        children: [
+          Icon(
+            Icons.check_circle,
+            color: theme.colorScheme.primary,
+          ),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Text(
+              '权限已授予',
+              style: theme.textTheme.bodyLarge?.copyWith(
+                color: theme.colorScheme.primary,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+
+  Widget _buildPrivacyInfo(ThemeData theme) {
+    return Container(
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            '隐私说明',
+            style: theme.textTheme.titleMedium?.copyWith(
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+          const SizedBox(height: 8),
+          Text(
+            '• 所有数据仅存储在您的设备本地\n'
+            '• 我们不会收集或上传任何数据到服务器\n'
+            '• 您可以随时删除所有数据\n'
+            '• 应用使用数据仅用于统计和分析',
+            style: theme.textTheme.bodySmall?.copyWith(
+              color: theme.colorScheme.onSurface.withOpacity(0.7),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+

lib/screens/settings_screen.dart

@@ -0,0 +1,270 @@
+import 'package:flutter/material.dart';
+import '../theme/app_theme.dart';
+import 'category_management_screen.dart';
+import 'goal_setting_screen.dart';
+import 'export_data_screen.dart';
+import 'data_privacy_screen.dart';
+import 'about_screen.dart';
+import 'notification_settings_screen.dart';
+import 'appearance_settings_screen.dart';
+
+class SettingsScreen extends StatelessWidget {
+  const SettingsScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Settings'),
+      ),
+      body: ListView(
+        padding: const EdgeInsets.all(16),
+        children: [
+          _buildSettingsSection(
+            title: '应用分类',
+            icon: Icons.category,
+            subtitle: '管理应用分类规则',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const CategoryManagementScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+          const SizedBox(height: 8),
+          _buildSettingsSection(
+            title: '时间目标',
+            icon: Icons.flag,
+            subtitle: '设置每日时间目标',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const GoalSettingScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+          const SizedBox(height: 8),
+          _buildSettingsSection(
+            title: '数据导出',
+            icon: Icons.file_download,
+            subtitle: '导出 CSV 数据、统计报告',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const ExportDataScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+          const SizedBox(height: 8),
+          _buildSettingsSection(
+            title: '数据与隐私',
+            icon: Icons.security,
+            subtitle: '数据管理、删除',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const DataPrivacyScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+          const SizedBox(height: 8),
+          _buildSettingsSection(
+            title: '通知设置',
+            icon: Icons.notifications,
+            subtitle: '目标提醒、每日报告',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const NotificationSettingsScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+          const SizedBox(height: 8),
+          _buildSettingsSection(
+            title: '外观设置',
+            icon: Icons.palette,
+            subtitle: '主题、字体大小',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const AppearanceSettingsScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+          const SizedBox(height: 24),
+          _buildUpgradeCard(theme),
+          const SizedBox(height: 24),
+          _buildSettingsSection(
+            title: '关于',
+            icon: Icons.info,
+            subtitle: '版本信息、帮助、反馈',
+            onTap: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const AboutScreen(),
+                ),
+              );
+            },
+            theme: theme,
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildSettingsSection({
+    required String title,
+    required IconData icon,
+    required String subtitle,
+    required VoidCallback onTap,
+    required ThemeData theme,
+  }) {
+    return Card(
+      child: ListTile(
+        leading: Container(
+          width: 40,
+          height: 40,
+          decoration: BoxDecoration(
+            color: AppTheme.primaryColor.withOpacity(0.1),
+            borderRadius: BorderRadius.circular(8),
+          ),
+          child: Icon(
+            icon,
+            color: AppTheme.primaryColor,
+          ),
+        ),
+        title: Text(
+          title,
+          style: theme.textTheme.bodyLarge?.copyWith(
+            fontWeight: FontWeight.w600,
+          ),
+        ),
+        subtitle: Text(
+          subtitle,
+          style: theme.textTheme.bodySmall?.copyWith(
+            color: theme.colorScheme.onSurface.withOpacity(0.6),
+          ),
+        ),
+        trailing: const Icon(Icons.chevron_right),
+        onTap: onTap,
+      ),
+    );
+  }
+
+  Widget _buildUpgradeCard(ThemeData theme) {
+    return Container(
+      padding: const EdgeInsets.all(20),
+      decoration: BoxDecoration(
+        gradient: LinearGradient(
+          colors: [
+            AppTheme.primaryColor,
+            AppTheme.secondaryColor,
+          ],
+          begin: Alignment.topLeft,
+          end: Alignment.bottomRight,
+        ),
+        borderRadius: BorderRadius.circular(16),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              Container(
+                padding: const EdgeInsets.all(8),
+                decoration: BoxDecoration(
+                  color: Colors.white.withOpacity(0.2),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: const Icon(
+                  Icons.diamond,
+                  color: Colors.white,
+                  size: 24,
+                ),
+              ),
+              const SizedBox(width: 12),
+              Text(
+                'Upgrade to Pro',
+                style: theme.textTheme.titleLarge?.copyWith(
+                  color: Colors.white,
+                  fontWeight: FontWeight.bold,
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 12),
+          Text(
+            '解锁高级功能',
+            style: theme.textTheme.bodyMedium?.copyWith(
+              color: Colors.white.withOpacity(0.9),
+            ),
+          ),
+          const SizedBox(height: 8),
+          ...[
+            '无限历史数据',
+            '高级统计分析',
+            '效率评分与分析',
+            '个性化建议',
+            '数据导出',
+          ].map((feature) => Padding(
+                padding: const EdgeInsets.only(bottom: 4),
+                child: Row(
+                  children: [
+                    const Icon(
+                      Icons.check_circle,
+                      color: Colors.white,
+                      size: 16,
+                    ),
+                    const SizedBox(width: 8),
+                    Text(
+                      feature,
+                      style: theme.textTheme.bodySmall?.copyWith(
+                        color: Colors.white.withOpacity(0.9),
+                      ),
+                    ),
+                  ],
+                ),
+              )),
+          const SizedBox(height: 16),
+          SizedBox(
+            width: double.infinity,
+            child: ElevatedButton(
+              onPressed: () {
+                // 打开订阅页面
+              },
+              style: ElevatedButton.styleFrom(
+                backgroundColor: Colors.white,
+                foregroundColor: AppTheme.primaryColor,
+                padding: const EdgeInsets.symmetric(vertical: 12),
+                shape: RoundedRectangleBorder(
+                  borderRadius: BorderRadius.circular(8),
+                ),
+              ),
+              child: const Text(
+                '立即升级',
+                style: TextStyle(
+                  fontWeight: FontWeight.w600,
+                ),
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+

lib/screens/stats_screen.dart

@@ -0,0 +1,564 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:fl_chart/fl_chart.dart';
+import 'package:intl/intl.dart';
+import '../theme/app_theme.dart';
+import '../providers/statistics_provider.dart';
+import '../models/daily_stats.dart';
+import '../widgets/empty_state_widget.dart';
+import '../widgets/error_state_widget.dart';
+
+class StatsScreen extends ConsumerStatefulWidget {
+  const StatsScreen({super.key});
+
+  @override
+  ConsumerState<StatsScreen> createState() => _StatsScreenState();
+}
+
+class _StatsScreenState extends ConsumerState<StatsScreen> {
+  String _selectedPeriod = '周'; // 日、周、月
+
+  // 根据时间段获取图表数据
+  List<Map<String, dynamic>> _getChartData(List<DailyStats>? stats, String period) {
+    if (stats != null && stats.isNotEmpty) {
+      return stats.map((stat) {
+        return {
+          'date': stat.date,
+          'total': stat.totalTime,
+          'work': stat.workTime,
+          'study': stat.studyTime,
+          'entertainment': stat.entertainmentTime,
+        };
+      }).toList();
+    }
+    
+    // 如果没有数据，使用默认测试数据
+    final now = DateTime.now();
+    
+    if (period == '日') {
+      // 日视图：显示今日数据（24小时，每小时一个点）
+      return List.generate(24, (index) {
+        final hour = now.subtract(Duration(hours: 23 - index));
+        return {
+          'date': hour,
+          'total': 1800 + (index % 3) * 300, // 模拟每小时30-60分钟
+          'work': 1200 + (index % 3) * 200,
+          'study': 300 + (index % 3) * 50,
+          'entertainment': 300 + (index % 3) * 50,
+        };
+      });
+    } else if (period == '周') {
+      // 周视图：显示7天数据
+      return [
+        {'date': now.subtract(const Duration(days: 6)), 'total': 21600, 'work': 14400, 'study': 3600, 'entertainment': 3600},
+        {'date': now.subtract(const Duration(days: 5)), 'total': 25200, 'work': 18000, 'study': 3600, 'entertainment': 3600},
+        {'date': now.subtract(const Duration(days: 4)), 'total': 23400, 'work': 16200, 'study': 3600, 'entertainment': 3600},
+        {'date': now.subtract(const Duration(days: 3)), 'total': 19800, 'work': 12600, 'study': 3600, 'entertainment': 3600},
+        {'date': now.subtract(const Duration(days: 2)), 'total': 27000, 'work': 19800, 'study': 3600, 'entertainment': 3600},
+        {'date': now.subtract(const Duration(days: 1)), 'total': 22500, 'work': 15300, 'study': 3600, 'entertainment': 3600},
+        {'date': now, 'total': 23040, 'work': 14400, 'study': 3600, 'entertainment': 3600},
+      ];
+    } else {
+      // 月视图：显示30天数据（简化版，每天一个点）
+      return List.generate(30, (index) {
+        final date = now.subtract(Duration(days: 29 - index));
+        return {
+          'date': date,
+          'total': 18000 + (index % 7) * 2000, // 模拟每天5-7小时
+          'work': 12000 + (index % 7) * 1500,
+          'study': 3000 + (index % 7) * 300,
+          'entertainment': 3000 + (index % 7) * 200,
+        };
+      });
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    
+    // 根据选中的时间段选择不同的 Provider
+    final statsAsync = _selectedPeriod == '日'
+        ? ref.watch(todayStatsListProvider)
+        : _selectedPeriod == '周'
+            ? ref.watch(weekStatsProvider)
+            : ref.watch(monthStatsProvider);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Statistics'),
+        actions: [
+          IconButton(
+            icon: const Icon(Icons.file_download),
+            onPressed: () {
+              // 导出数据
+            },
+          ),
+        ],
+      ),
+      body: statsAsync.when(
+        data: (stats) {
+          final chartData = _getChartData(stats, _selectedPeriod);
+          // 检查是否为空数据
+          final isEmpty = chartData.isEmpty || chartData.every((data) => (data['total'] as int) == 0);
+          if (isEmpty) {
+            return EmptyStateWidget.noData(
+              title: '暂无统计数据',
+              subtitle: '使用应用一段时间后，统计数据将显示在这里',
+              actionLabel: '刷新',
+              onAction: () {
+                if (_selectedPeriod == '日') {
+                  ref.invalidate(todayStatsListProvider);
+                } else if (_selectedPeriod == '周') {
+                  ref.invalidate(weekStatsProvider);
+                } else {
+                  ref.invalidate(monthStatsProvider);
+                }
+              },
+            );
+          }
+          return SingleChildScrollView(
+            padding: const EdgeInsets.all(16),
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                // 时间选择器
+                _buildPeriodSelector(theme),
+                const SizedBox(height: 24),
+
+                // 时间趋势图
+                _buildTrendChart(theme, chartData, _selectedPeriod),
+                const SizedBox(height: 24),
+
+                // 分类对比图
+                _buildCategoryChart(theme, chartData, _selectedPeriod),
+                const SizedBox(height: 24),
+
+                // 应用使用详情
+                _buildAppDetails(theme),
+              ],
+            ),
+          );
+        },
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, stack) => ErrorStateWidget.dataLoad(
+          message: _getErrorMessage(error),
+          onRetry: () {
+            if (_selectedPeriod == '日') {
+              ref.invalidate(todayStatsListProvider);
+            } else if (_selectedPeriod == '周') {
+              ref.invalidate(weekStatsProvider);
+            } else {
+              ref.invalidate(monthStatsProvider);
+            }
+          },
+        ),
+      ),
+    );
+  }
+
+  Widget _buildPeriodSelector(ThemeData theme) {
+    return Row(
+      children: [
+        Expanded(
+          child: SegmentedButton<String>(
+            segments: const [
+              ButtonSegment(value: '日', label: Text('日')),
+              ButtonSegment(value: '周', label: Text('周')),
+              ButtonSegment(value: '月', label: Text('月')),
+            ],
+            selected: {_selectedPeriod},
+            onSelectionChanged: (Set<String> newSelection) {
+              final newPeriod = newSelection.first;
+              setState(() {
+                _selectedPeriod = newPeriod;
+              });
+              // 切换时间段时，刷新对应的 Provider
+              if (newPeriod == '日') {
+                ref.invalidate(todayStatsListProvider);
+              } else if (newPeriod == '周') {
+                ref.invalidate(weekStatsProvider);
+              } else {
+                ref.invalidate(monthStatsProvider);
+              }
+            },
+          ),
+        ),
+        const SizedBox(width: 12),
+        IconButton(
+          icon: const Icon(Icons.file_download),
+          onPressed: () {
+            // 导出功能
+          },
+        ),
+      ],
+    );
+  }
+
+  Widget _buildTrendChart(ThemeData theme, List<Map<String, dynamic>> chartData, String period) {
+    return Container(
+      height: 250,
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            period == '日' ? '每小时总时长趋势' : period == '周' ? '每日总时长趋势' : '每日总时长趋势（月）',
+            style: theme.textTheme.titleMedium?.copyWith(
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+          const SizedBox(height: 16),
+          Expanded(
+            child: LineChart(
+              LineChartData(
+                gridData: FlGridData(
+                  show: true,
+                  drawVerticalLine: false,
+                  horizontalInterval: 2,
+                  getDrawingHorizontalLine: (value) {
+                    return FlLine(
+                      color: theme.colorScheme.onSurface.withOpacity(0.1),
+                      strokeWidth: 1,
+                    );
+                  },
+                ),
+                titlesData: FlTitlesData(
+                  leftTitles: AxisTitles(
+                    sideTitles: SideTitles(
+                      showTitles: true,
+                      reservedSize: 40,
+                      getTitlesWidget: (value, meta) {
+                        return Text(
+                          '${(value / 3600).toStringAsFixed(1)}h',
+                          style: TextStyle(
+                            fontSize: 10,
+                            color: theme.colorScheme.onSurface.withOpacity(0.6),
+                          ),
+                        );
+                      },
+                    ),
+                  ),
+                  bottomTitles: AxisTitles(
+                    sideTitles: SideTitles(
+                      showTitles: true,
+                      reservedSize: 30,
+                      getTitlesWidget: (value, meta) {
+                        if (value.toInt() >= 0 && value.toInt() < chartData.length) {
+                          final date = chartData[value.toInt()]['date'] as DateTime;
+                          String label;
+                          if (period == '日') {
+                            label = DateFormat('HH:mm', 'zh_CN').format(date);
+                          } else if (period == '周') {
+                            label = DateFormat('E', 'zh_CN').format(date);
+                          } else {
+                            label = DateFormat('M/d', 'zh_CN').format(date);
+                          }
+                          return Text(
+                            label,
+                            style: TextStyle(
+                              fontSize: 10,
+                              color: theme.colorScheme.onSurface.withOpacity(0.6),
+                            ),
+                          );
+                        }
+                        return const Text('');
+                      },
+                    ),
+                  ),
+                  rightTitles: const AxisTitles(
+                    sideTitles: SideTitles(showTitles: false),
+                  ),
+                  topTitles: const AxisTitles(
+                    sideTitles: SideTitles(showTitles: false),
+                  ),
+                ),
+                borderData: FlBorderData(show: false),
+                lineBarsData: [
+                  LineChartBarData(
+                    spots: chartData.asMap().entries.map((entry) {
+                      return FlSpot(
+                        entry.key.toDouble(),
+                        (entry.value['total'] as int) / 3600.0,
+                      );
+                    }).toList(),
+                    isCurved: true,
+                    color: AppTheme.primaryColor,
+                    barWidth: 3,
+                    dotData: const FlDotData(show: true),
+                    belowBarData: BarAreaData(
+                      show: true,
+                      color: AppTheme.primaryColor.withOpacity(0.1),
+                    ),
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildCategoryChart(ThemeData theme, List<Map<String, dynamic>> chartData, String period) {
+    return Container(
+      height: 300,
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            period == '日' ? '每小时分类时间分布' : period == '周' ? '每日分类时间分布' : '每日分类时间分布（月）',
+            style: theme.textTheme.titleMedium?.copyWith(
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+          const SizedBox(height: 16),
+          Expanded(
+            child: BarChart(
+              BarChartData(
+                alignment: BarChartAlignment.spaceAround,
+                maxY: 8,
+                barTouchData: BarTouchData(enabled: false),
+                titlesData: FlTitlesData(
+                  leftTitles: AxisTitles(
+                    sideTitles: SideTitles(
+                      showTitles: true,
+                      reservedSize: 40,
+                      getTitlesWidget: (value, meta) {
+                        return Text(
+                          '${value.toInt()}h',
+                          style: TextStyle(
+                            fontSize: 10,
+                            color: theme.colorScheme.onSurface.withOpacity(0.6),
+                          ),
+                        );
+                      },
+                    ),
+                  ),
+                  bottomTitles: AxisTitles(
+                    sideTitles: SideTitles(
+                      showTitles: true,
+                      reservedSize: 30,
+                      getTitlesWidget: (value, meta) {
+                        if (value.toInt() >= 0 && value.toInt() < chartData.length) {
+                          final date = chartData[value.toInt()]['date'] as DateTime;
+                          String label;
+                          if (period == '日') {
+                            label = DateFormat('HH:mm', 'zh_CN').format(date);
+                          } else if (period == '周') {
+                            label = DateFormat('M/d', 'zh_CN').format(date);
+                          } else {
+                            label = DateFormat('M/d', 'zh_CN').format(date);
+                          }
+                          return Text(
+                            label,
+                            style: TextStyle(
+                              fontSize: 10,
+                              color: theme.colorScheme.onSurface.withOpacity(0.6),
+                            ),
+                          );
+                        }
+                        return const Text('');
+                      },
+                    ),
+                  ),
+                  rightTitles: const AxisTitles(
+                    sideTitles: SideTitles(showTitles: false),
+                  ),
+                  topTitles: const AxisTitles(
+                    sideTitles: SideTitles(showTitles: false),
+                  ),
+                ),
+                gridData: FlGridData(
+                  show: true,
+                  drawVerticalLine: false,
+                  getDrawingHorizontalLine: (value) {
+                    return FlLine(
+                      color: theme.colorScheme.onSurface.withOpacity(0.1),
+                      strokeWidth: 1,
+                    );
+                  },
+                ),
+                borderData: FlBorderData(show: false),
+                barGroups: chartData.asMap().entries.map((entry) {
+                  final data = entry.value;
+                  return BarChartGroupData(
+                    x: entry.key,
+                    barRods: [
+                      BarChartRodData(
+                        toY: (data['work'] as int) / 3600.0,
+                        color: AppTheme.workColor,
+                        width: 12,
+                        borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
+                      ),
+                      BarChartRodData(
+                        toY: (data['study'] as int) / 3600.0,
+                        color: AppTheme.studyColor,
+                        width: 12,
+                        borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
+                      ),
+                      BarChartRodData(
+                        toY: (data['entertainment'] as int) / 3600.0,
+                        color: AppTheme.entertainmentColor,
+                        width: 12,
+                        borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
+                      ),
+                    ],
+                  );
+                }).toList(),
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildAppDetails(ThemeData theme) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Text(
+          '应用使用详情',
+          style: theme.textTheme.titleMedium?.copyWith(
+            fontWeight: FontWeight.w600,
+          ),
+        ),
+        const SizedBox(height: 12),
+        _buildAppDetailItem('Chrome', '今日: 2h 15m', '本周: 12h 30m', '工作', theme),
+        _buildAppDetailItem('VS Code', '今日: 1h 30m', '本周: 8h 45m', '工作', theme),
+        _buildAppDetailItem('Slack', '今日: 1h', '本周: 6h', '工作', theme),
+      ],
+    );
+  }
+
+  Widget _buildAppDetailItem(
+    String appName,
+    String todayTime,
+    String weekTime,
+    String category,
+    ThemeData theme,
+  ) {
+    return Container(
+      margin: const EdgeInsets.only(bottom: 8),
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(8),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              Container(
+                width: 40,
+                height: 40,
+                decoration: BoxDecoration(
+                  color: AppTheme.getCategoryColor(category).withOpacity(0.1),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: Icon(
+                  Icons.phone_android,
+                  color: AppTheme.getCategoryColor(category),
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      appName,
+                      style: theme.textTheme.bodyLarge?.copyWith(
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 4),
+                    Text(
+                      '分类: $category',
+                      style: theme.textTheme.bodySmall?.copyWith(
+                        color: theme.colorScheme.onSurface.withOpacity(0.6),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 12),
+          Row(
+            mainAxisAlignment: MainAxisAlignment.spaceAround,
+            children: [
+              Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Text(
+                    '今日',
+                    style: theme.textTheme.bodySmall?.copyWith(
+                      color: theme.colorScheme.onSurface.withOpacity(0.6),
+                    ),
+                  ),
+                  const SizedBox(height: 4),
+                  Text(
+                    todayTime,
+                    style: theme.textTheme.bodyMedium?.copyWith(
+                      fontWeight: FontWeight.w600,
+                      color: AppTheme.primaryColor,
+                    ),
+                  ),
+                ],
+              ),
+              Container(
+                width: 1,
+                height: 40,
+                color: theme.colorScheme.onSurface.withOpacity(0.1),
+              ),
+              Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Text(
+                    '本周',
+                    style: theme.textTheme.bodySmall?.copyWith(
+                      color: theme.colorScheme.onSurface.withOpacity(0.6),
+                    ),
+                  ),
+                  const SizedBox(height: 4),
+                  Text(
+                    weekTime,
+                    style: theme.textTheme.bodyMedium?.copyWith(
+                      fontWeight: FontWeight.w600,
+                      color: AppTheme.primaryColor,
+                    ),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+
+  String _getErrorMessage(Object error) {
+    final errorString = error.toString().toLowerCase();
+    if (errorString.contains('permission') || errorString.contains('权限')) {
+      return '需要授予应用使用权限';
+    } else if (errorString.contains('network') || errorString.contains('网络')) {
+      return '网络连接失败，请检查网络';
+    } else if (errorString.contains('database') || errorString.contains('数据库')) {
+      return '数据库操作失败';
+    }
+    return '加载失败，请稍后重试';
+  }
+}
+

lib/screens/today_screen.dart

@@ -0,0 +1,407 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:fl_chart/fl_chart.dart';
+import '../theme/app_theme.dart';
+import '../models/daily_stats.dart';
+import '../models/app_usage.dart';
+import '../providers/statistics_provider.dart';
+import '../widgets/empty_state_widget.dart';
+import '../widgets/error_state_widget.dart';
+
+class TodayScreen extends ConsumerWidget {
+  const TodayScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final todayStatsAsync = ref.watch(todayStatsProvider);
+    final topAppsAsync = ref.watch(todayTopAppsProvider);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('AutoTime Tracker'),
+        actions: [
+          IconButton(
+            icon: const Icon(Icons.refresh),
+            onPressed: () {
+              ref.invalidate(todayStatsProvider);
+              ref.invalidate(todayTopAppsProvider);
+            },
+          ),
+                IconButton(
+                  icon: const Icon(Icons.settings),
+                  onPressed: () {
+                    // 设置页面通过底部导航栏访问
+                  },
+                ),
+        ],
+      ),
+      body: todayStatsAsync.when(
+        data: (stats) {
+          // 检查是否为空数据（总时长为0且没有应用数据）
+          final isEmpty = stats.totalTime == 0;
+          if (isEmpty) {
+            return _buildEmptyContent(context, ref);
+          }
+          return _buildContent(context, ref, stats, topAppsAsync);
+        },
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, stack) => ErrorStateWidget.dataLoad(
+          message: _getErrorMessage(error),
+          onRetry: () {
+            ref.invalidate(todayStatsProvider);
+            ref.invalidate(todayTopAppsProvider);
+          },
+        ),
+      ),
+    );
+  }
+
+  Widget _buildContent(
+    BuildContext context,
+    WidgetRef ref,
+    DailyStats stats,
+    AsyncValue<List<AppUsage>> topAppsAsync,
+  ) {
+    final theme = Theme.of(context);
+
+    return RefreshIndicator(
+      onRefresh: () async {
+        ref.invalidate(todayStatsProvider);
+        ref.invalidate(todayTopAppsProvider);
+      },
+      child: SingleChildScrollView(
+        physics: const AlwaysScrollableScrollPhysics(),
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // 总时长显示
+            _buildTotalTimeSection(stats, theme),
+            const SizedBox(height: 24),
+
+            // 效率评分
+            _buildEfficiencySection(stats, theme),
+            const SizedBox(height: 24),
+
+            // 分类时间分布（饼图）
+            _buildCategoryChart(stats, theme),
+            const SizedBox(height: 24),
+
+            // 分类标签
+            _buildCategoryTags(theme),
+            const SizedBox(height: 24),
+
+            // Top 应用列表
+            _buildTopAppsSection(context, ref, theme, topAppsAsync),
+          ],
+        ),
+      ),
+    );
+  }
+
+
+  Widget _buildTotalTimeSection(DailyStats stats, ThemeData theme) {
+    return Center(
+      child: Column(
+        children: [
+          Text(
+            stats.formattedTotalTime,
+            style: theme.textTheme.displayLarge?.copyWith(
+              fontSize: 48,
+              fontWeight: FontWeight.bold,
+              color: AppTheme.primaryColor,
+            ),
+          ),
+          const SizedBox(height: 8),
+          Text(
+            '今日总时长',
+            style: theme.textTheme.bodyLarge?.copyWith(
+              color: theme.colorScheme.onSurface.withOpacity(0.6),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildEfficiencySection(DailyStats stats, ThemeData theme) {
+    final score = stats.efficiencyScore ?? 0;
+    final color = stats.efficiencyColor;
+
+    return Container(
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+        children: [
+          Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Text(
+                '效率评分',
+                style: theme.textTheme.bodyMedium?.copyWith(
+                  color: theme.colorScheme.onSurface.withOpacity(0.6),
+                ),
+              ),
+              const SizedBox(height: 4),
+              Row(
+                children: [
+                  Text(
+                    '$score%',
+                    style: theme.textTheme.headlineMedium?.copyWith(
+                      fontWeight: FontWeight.bold,
+                      color: color,
+                    ),
+                  ),
+                  const SizedBox(width: 8),
+                  ...List.generate(5, (index) {
+                    return Icon(
+                      index < (score / 20).floor()
+                          ? Icons.star
+                          : Icons.star_border,
+                      size: 20,
+                      color: color,
+                    );
+                  }),
+                ],
+              ),
+            ],
+          ),
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+            decoration: BoxDecoration(
+              color: color.withOpacity(0.1),
+              borderRadius: BorderRadius.circular(20),
+            ),
+            child: Text(
+              _getEfficiencyText(score),
+              style: TextStyle(
+                color: color,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  String _getEfficiencyText(int score) {
+    if (score >= 80) return '优秀';
+    if (score >= 60) return '良好';
+    if (score >= 40) return '一般';
+    return '需改进';
+  }
+
+  Widget _buildCategoryChart(DailyStats stats, ThemeData theme) {
+    final categoryData = [
+      {'category': 'work', 'time': stats.workTime, 'color': AppTheme.workColor},
+      {'category': 'study', 'time': stats.studyTime, 'color': AppTheme.studyColor},
+      {'category': 'entertainment', 'time': stats.entertainmentTime, 'color': AppTheme.entertainmentColor},
+      {'category': 'social', 'time': stats.socialTime, 'color': AppTheme.socialColor},
+      {'category': 'tool', 'time': stats.toolTime, 'color': AppTheme.toolColor},
+    ].where((item) => item['time'] as int > 0).toList();
+
+    return Container(
+      height: 300,
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            '分类时间分布',
+            style: theme.textTheme.titleMedium?.copyWith(
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+          const SizedBox(height: 16),
+          Expanded(
+            child: PieChart(
+              PieChartData(
+                sections: categoryData.map((item) {
+                  final time = item['time'] as int;
+                  final total = stats.totalTime;
+                  final percentage = (time / total * 100);
+                  return PieChartSectionData(
+                    value: time.toDouble(),
+                    title: '${percentage.toStringAsFixed(1)}%',
+                    color: item['color'] as Color,
+                    radius: 80,
+                    titleStyle: const TextStyle(
+                      fontSize: 12,
+                      fontWeight: FontWeight.bold,
+                      color: Colors.white,
+                    ),
+                  );
+                }).toList(),
+                sectionsSpace: 2,
+                centerSpaceRadius: 60,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildCategoryTags(ThemeData theme) {
+    final categories = ['work', 'study', 'entertainment', 'social', 'tool'];
+
+    return Wrap(
+      spacing: 8,
+      runSpacing: 8,
+      children: categories.map((category) {
+        return FilterChip(
+          label: Text(AppTheme.getCategoryName(category)),
+          selected: false,
+          onSelected: (selected) {
+            // 筛选该分类
+          },
+          backgroundColor: AppTheme.getCategoryColor(category).withOpacity(0.1),
+          selectedColor: AppTheme.getCategoryColor(category),
+          labelStyle: TextStyle(
+            color: AppTheme.getCategoryColor(category),
+            fontWeight: FontWeight.w500,
+          ),
+        );
+      }).toList(),
+    );
+  }
+
+  Widget _buildTopAppsSection(BuildContext context, WidgetRef ref, ThemeData theme, AsyncValue<List<AppUsage>> topAppsAsync) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Text(
+          'Top Apps Today',
+          style: theme.textTheme.titleMedium?.copyWith(
+            fontWeight: FontWeight.w600,
+          ),
+        ),
+        const SizedBox(height: 12),
+        topAppsAsync.when(
+          data: (apps) {
+            if (apps.isEmpty) {
+              return EmptyStateWidget.noApps(
+                onAction: () {
+                  ref.invalidate(todayTopAppsProvider);
+                },
+              );
+            }
+            return Column(
+              children: apps.map((app) => _buildAppItem(app, theme)).toList(),
+            );
+          },
+          loading: () => const Center(
+            child: Padding(
+              padding: EdgeInsets.all(16),
+              child: CircularProgressIndicator(),
+            ),
+          ),
+          error: (error, stack) => Padding(
+            padding: const EdgeInsets.all(16),
+            child: ErrorStateWidget.dataLoad(
+              message: _getErrorMessage(error),
+              onRetry: () {
+                ref.invalidate(todayTopAppsProvider);
+              },
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+
+  Widget _buildEmptyContent(BuildContext context, WidgetRef ref) {
+    return RefreshIndicator(
+      onRefresh: () async {
+        ref.invalidate(todayStatsProvider);
+        ref.invalidate(todayTopAppsProvider);
+      },
+      child: SingleChildScrollView(
+        physics: const AlwaysScrollableScrollPhysics(),
+        child: EmptyStateWidget.firstTime(
+          onAction: () {
+            // 可以导航到权限设置页面
+            Navigator.of(context).pushNamed('/permission');
+          },
+        ),
+      ),
+    );
+  }
+
+  String _getErrorMessage(Object error) {
+    final errorString = error.toString().toLowerCase();
+    if (errorString.contains('permission') || errorString.contains('权限')) {
+      return '需要授予应用使用权限';
+    } else if (errorString.contains('network') || errorString.contains('网络')) {
+      return '网络连接失败，请检查网络';
+    } else if (errorString.contains('database') || errorString.contains('数据库')) {
+      return '数据库操作失败';
+    }
+    return '加载失败，请稍后重试';
+  }
+
+  Widget _buildAppItem(AppUsage app, ThemeData theme) {
+    return Container(
+      margin: const EdgeInsets.only(bottom: 8),
+      padding: const EdgeInsets.all(12),
+      decoration: BoxDecoration(
+        color: theme.cardColor,
+        borderRadius: BorderRadius.circular(8),
+      ),
+      child: Row(
+        children: [
+          Container(
+            width: 40,
+            height: 40,
+            decoration: BoxDecoration(
+              color: AppTheme.getCategoryColor(app.category).withOpacity(0.1),
+              borderRadius: BorderRadius.circular(8),
+            ),
+            child: Icon(
+              Icons.phone_android,
+              color: AppTheme.getCategoryColor(app.category),
+            ),
+          ),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  app.appName,
+                  style: theme.textTheme.bodyLarge?.copyWith(
+                    fontWeight: FontWeight.w500,
+                  ),
+                ),
+                const SizedBox(height: 4),
+                Text(
+                  AppTheme.getCategoryName(app.category),
+                  style: theme.textTheme.bodySmall?.copyWith(
+                    color: theme.colorScheme.onSurface.withOpacity(0.6),
+                  ),
+                ),
+              ],
+            ),
+          ),
+          Text(
+            app.formattedDuration,
+            style: theme.textTheme.bodyLarge?.copyWith(
+              fontWeight: FontWeight.w600,
+              color: AppTheme.primaryColor,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+

lib/services/background_sync_service.dart

@@ -0,0 +1,60 @@
+import 'dart:async';
+import 'time_tracking_service.dart';
+import 'statistics_service.dart';
+
+/// 后台同步服务 - 定期同步应用使用数据
+class BackgroundSyncService {
+  final TimeTrackingService _timeTrackingService = TimeTrackingService();
+  final StatisticsService _statisticsService = StatisticsService();
+  
+  Timer? _syncTimer;
+  bool _isRunning = false;
+
+  /// 启动后台同步
+  Future<void> start() async {
+    if (_isRunning) return;
+
+    _isRunning = true;
+    
+    // 立即同步一次
+    await syncNow();
+
+    // 每 15 分钟同步一次
+    _syncTimer = Timer.periodic(const Duration(minutes: 15), (timer) async {
+      await syncNow();
+    });
+
+    // 启动原生后台追踪
+    await _timeTrackingService.startBackgroundTracking();
+  }
+
+  /// 停止后台同步
+  Future<void> stop() async {
+    _isRunning = false;
+    _syncTimer?.cancel();
+    _syncTimer = null;
+    
+    await _timeTrackingService.stopBackgroundTracking();
+  }
+
+  /// 立即同步
+  Future<void> syncNow() async {
+    try {
+      print('Background sync: Starting sync...');
+      
+      // 同步今日数据
+      await _timeTrackingService.syncTodayData();
+      
+      // 刷新统计
+      await _statisticsService.refreshTodayStats();
+      
+      print('Background sync: Completed');
+    } catch (e) {
+      print('Background sync error: $e');
+    }
+  }
+
+  /// 检查是否正在运行
+  bool get isRunning => _isRunning;
+}
+

lib/services/category_service.dart

@@ -0,0 +1,183 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:sqflite/sqflite.dart';
+import '../database/database_helper.dart';
+
+class CategoryService {
+  final DatabaseHelper _dbHelper = DatabaseHelper.instance;
+  
+  // Web 平台使用内存存储
+  final Map<String, String> _webCustomCategories = {};
+
+  // 预设分类规则
+  static const Map<String, String> defaultCategories = {
+    // 工作类
+    'com.microsoft.Office.Word': 'work',
+    'com.microsoft.Office.Excel': 'work',
+    'com.microsoft.Office.PowerPoint': 'work',
+    'com.slack': 'work',
+    'com.notion.Notion': 'work',
+    'com.figma.Figma': 'work',
+    'com.github': 'work',
+    'com.microsoft.VSCode': 'work',
+    'com.jetbrains': 'work',
+    'com.google.android.apps.docs': 'work',
+    'com.google.android.apps.sheets': 'work',
+    
+    // 学习类
+    'com.coursera': 'study',
+    'com.khanacademy': 'study',
+    'com.amazon.kindle': 'study',
+    'com.gingerlabs.Notability': 'study',
+    'com.goodnotes': 'study',
+    'com.anki': 'study',
+    'com.duolingo': 'study',
+    
+    // 娱乐类
+    'com.google.YouTube': 'entertainment',
+    'com.netflix.Netflix': 'entertainment',
+    'com.spotify.music': 'entertainment',
+    'com.spotify.client': 'entertainment',
+    'com.disney': 'entertainment',
+    
+    // 社交类
+    'net.whatsapp.WhatsApp': 'social',
+    'com.instagram': 'social',
+    'com.twitter': 'social',
+    'com.facebook.Facebook': 'social',
+    'com.tencent.mm': 'social', // 微信
+    'com.tencent.mobileqq': 'social', // QQ
+    
+    // 工具类
+    'com.apple.Safari': 'tool',
+    'com.android.chrome': 'tool',
+    'com.google.chrome': 'tool',
+    'com.microsoft.edge': 'tool',
+    'com.apple.mobilemail': 'tool',
+    'com.google.Gmail': 'tool',
+  };
+
+  // 获取应用分类
+  Future<String> getCategory(String packageName) async {
+    // 1. 先查用户自定义分类
+    final customCategory = await _getCustomCategory(packageName);
+    if (customCategory != null) {
+      return customCategory;
+    }
+
+    // 2. 查系统预设分类
+    if (defaultCategories.containsKey(packageName)) {
+      return defaultCategories[packageName]!;
+    }
+
+    // 3. 默认分类
+    return 'other';
+  }
+
+  // 获取用户自定义分类
+  Future<String?> _getCustomCategory(String packageName) async {
+    // Web 平台使用内存存储
+    if (kIsWeb) {
+      return _webCustomCategories[packageName];
+    }
+
+    final db = await _dbHelper.database;
+    final maps = await db.query(
+      'app_category',
+      where: 'package_name = ? AND is_custom = 1',
+      whereArgs: [packageName],
+    );
+
+    if (maps.isEmpty) return null;
+    return maps.first['category'] as String;
+  }
+
+  // 设置自定义分类
+  Future<void> setCategory(String packageName, String category) async {
+    // Web 平台使用内存存储
+    if (kIsWeb) {
+      _webCustomCategories[packageName] = category;
+      return;
+    }
+
+    final db = await _dbHelper.database;
+    final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+
+    await db.insert(
+      'app_category',
+      {
+        'package_name': packageName,
+        'category': category,
+        'is_custom': 1,
+        'created_at': now,
+        'updated_at': now,
+      },
+      conflictAlgorithm: ConflictAlgorithm.replace,
+    );
+  }
+
+  // 删除自定义分类（恢复为系统默认）
+  Future<void> removeCustomCategory(String packageName) async {
+    // Web 平台使用内存存储
+    if (kIsWeb) {
+      _webCustomCategories.remove(packageName);
+      return;
+    }
+
+    final db = await _dbHelper.database;
+    await db.delete(
+      'app_category',
+      where: 'package_name = ? AND is_custom = 1',
+      whereArgs: [packageName],
+    );
+  }
+
+  // 获取所有自定义分类
+  Future<Map<String, String>> getAllCustomCategories() async {
+    // Web 平台使用内存存储
+    if (kIsWeb) {
+      return Map<String, String>.from(_webCustomCategories);
+    }
+
+    final db = await _dbHelper.database;
+    final maps = await db.query(
+      'app_category',
+      where: 'is_custom = 1',
+    );
+
+    final result = <String, String>{};
+    for (final map in maps) {
+      result[map['package_name'] as String] = map['category'] as String;
+    }
+    return result;
+  }
+
+  // 批量设置分类
+  Future<void> batchSetCategories(Map<String, String> categories) async {
+    // Web 平台使用内存存储
+    if (kIsWeb) {
+      _webCustomCategories.addAll(categories);
+      return;
+    }
+
+    final db = await _dbHelper.database;
+    final batch = db.batch();
+    final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+
+    for (final entry in categories.entries) {
+      batch.insert(
+        'app_category',
+        {
+          'package_name': entry.key,
+          'category': entry.value,
+          'is_custom': 1,
+          'created_at': now,
+          'updated_at': now,
+        },
+        conflictAlgorithm: ConflictAlgorithm.replace,
+      );
+    }
+
+    await batch.commit(noResult: true);
+  }
+}
+

lib/services/export_service.dart

@@ -0,0 +1,156 @@
+import '../database/app_usage_dao.dart';
+import '../database/daily_stats_dao.dart';
+import '../theme/app_theme.dart';
+
+class ExportService {
+  final AppUsageDao _appUsageDao = AppUsageDao();
+  final DailyStatsDao _dailyStatsDao = DailyStatsDao();
+
+  /// 导出 CSV 格式数据
+  Future<String> exportToCSV({
+    required DateTime startDate,
+    required DateTime endDate,
+  }) async {
+    final appUsages = await _appUsageDao.getAppUsages(
+      startTime: startDate,
+      endTime: endDate,
+    );
+
+    final buffer = StringBuffer();
+    
+    // CSV 头部
+    buffer.writeln('应用名称,包名,开始时间,结束时间,使用时长(秒),使用时长(格式化),分类');
+
+    // 数据行
+    for (final usage in appUsages) {
+      buffer.writeln([
+        _escapeCsvField(usage.appName),
+        _escapeCsvField(usage.packageName),
+        usage.startTime.toIso8601String(),
+        usage.endTime.toIso8601String(),
+        usage.duration.toString(),
+        usage.formattedDuration,
+        AppTheme.getCategoryName(usage.category),
+      ].join(','));
+    }
+
+    return buffer.toString();
+  }
+
+  /// 导出统计报告（文本格式）
+  Future<String> exportStatsReport({
+    required DateTime startDate,
+    required DateTime endDate,
+  }) async {
+    final stats = await _dailyStatsDao.getStatsRange(
+      startDate: startDate,
+      endDate: endDate,
+    );
+
+    final buffer = StringBuffer();
+    
+    buffer.writeln('=== AutoTime Tracker 统计报告 ===');
+    buffer.writeln('报告时间: ${startDate.toString().split(' ')[0]} 至 ${endDate.toString().split(' ')[0]}');
+    buffer.writeln('');
+    buffer.writeln('日期统计:');
+    buffer.writeln('');
+
+    int totalWorkTime = 0;
+    int totalStudyTime = 0;
+    int totalEntertainmentTime = 0;
+    int totalSocialTime = 0;
+    int totalToolTime = 0;
+    int totalTime = 0;
+
+    for (final stat in stats) {
+      buffer.writeln('${stat.date.toString().split(' ')[0]}:');
+      buffer.writeln('  总时长: ${stat.formattedTotalTime}');
+      buffer.writeln('  工作: ${_formatTime(stat.workTime)}');
+      buffer.writeln('  学习: ${_formatTime(stat.studyTime)}');
+      buffer.writeln('  娱乐: ${_formatTime(stat.entertainmentTime)}');
+      buffer.writeln('  社交: ${_formatTime(stat.socialTime)}');
+      buffer.writeln('  工具: ${_formatTime(stat.toolTime)}');
+      if (stat.efficiencyScore != null) {
+        buffer.writeln('  效率评分: ${stat.efficiencyScore}%');
+      }
+      buffer.writeln('');
+
+      totalWorkTime += stat.workTime;
+      totalStudyTime += stat.studyTime;
+      totalEntertainmentTime += stat.entertainmentTime;
+      totalSocialTime += stat.socialTime;
+      totalToolTime += stat.toolTime;
+      totalTime += stat.totalTime;
+    }
+
+    buffer.writeln('总计:');
+    buffer.writeln('  总时长: ${_formatTime(totalTime)}');
+    buffer.writeln('  工作: ${_formatTime(totalWorkTime)} (${(totalWorkTime / totalTime * 100).toStringAsFixed(1)}%)');
+    buffer.writeln('  学习: ${_formatTime(totalStudyTime)} (${(totalStudyTime / totalTime * 100).toStringAsFixed(1)}%)');
+    buffer.writeln('  娱乐: ${_formatTime(totalEntertainmentTime)} (${(totalEntertainmentTime / totalTime * 100).toStringAsFixed(1)}%)');
+    buffer.writeln('  社交: ${_formatTime(totalSocialTime)} (${(totalSocialTime / totalTime * 100).toStringAsFixed(1)}%)');
+    buffer.writeln('  工具: ${_formatTime(totalToolTime)} (${(totalToolTime / totalTime * 100).toStringAsFixed(1)}%)');
+
+    return buffer.toString();
+  }
+
+  /// 导出今日报告
+  Future<String> exportTodayReport() async {
+    final today = DateTime.now();
+    final startOfDay = DateTime(today.year, today.month, today.day);
+    final endOfDay = startOfDay.add(const Duration(days: 1));
+
+    final stats = await _dailyStatsDao.getTodayStats();
+    final topApps = await _appUsageDao.getTopApps(
+      startTime: startOfDay,
+      endTime: endOfDay,
+      limit: 10,
+    );
+
+    final buffer = StringBuffer();
+    
+    buffer.writeln('=== AutoTime Tracker 今日报告 ===');
+    buffer.writeln('日期: ${today.toString().split(' ')[0]}');
+    buffer.writeln('');
+
+    if (stats != null) {
+      buffer.writeln('总时长: ${stats.formattedTotalTime}');
+      buffer.writeln('工作: ${_formatTime(stats.workTime)}');
+      buffer.writeln('学习: ${_formatTime(stats.studyTime)}');
+      buffer.writeln('娱乐: ${_formatTime(stats.entertainmentTime)}');
+      buffer.writeln('社交: ${_formatTime(stats.socialTime)}');
+      buffer.writeln('工具: ${_formatTime(stats.toolTime)}');
+      if (stats.efficiencyScore != null) {
+        buffer.writeln('效率评分: ${stats.efficiencyScore}%');
+      }
+      buffer.writeln('');
+    }
+
+    if (topApps.isNotEmpty) {
+      buffer.writeln('Top 应用:');
+      for (int i = 0; i < topApps.length; i++) {
+        final app = topApps[i];
+        buffer.writeln('${i + 1}. ${app.appName}: ${app.formattedDuration} (${AppTheme.getCategoryName(app.category)})');
+      }
+    }
+
+    return buffer.toString();
+  }
+
+  String _escapeCsvField(String field) {
+    if (field.contains(',') || field.contains('"') || field.contains('\n')) {
+      return '"${field.replaceAll('"', '""')}"';
+    }
+    return field;
+  }
+
+  String _formatTime(int seconds) {
+    final hours = seconds ~/ 3600;
+    final minutes = (seconds % 3600) ~/ 60;
+    if (hours > 0) {
+      return '${hours}h ${minutes}m';
+    }
+    return '${minutes}m';
+  }
+}
+

lib/services/mock_data_service.dart

@@ -0,0 +1,114 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../models/daily_stats.dart';
+import '../models/app_usage.dart';
+
+/// 测试数据服务 - 用于 Web 平台或开发测试
+class MockDataService {
+  /// 生成今日测试统计数据
+  static DailyStats generateTodayStats() {
+    return DailyStats(
+      date: DateTime.now(),
+      totalTime: 23040, // 6小时24分钟
+      workTime: 14400, // 4小时
+      studyTime: 3600, // 1小时
+      entertainmentTime: 3600, // 1小时
+      socialTime: 1800, // 30分钟
+      toolTime: 0,
+      efficiencyScore: 72,
+      focusScore: 65,
+      appSwitchCount: 45,
+      createdAt: DateTime.now(),
+      updatedAt: DateTime.now(),
+    );
+  }
+
+  /// 生成本周测试统计数据
+  static List<DailyStats> generateWeekStats() {
+    final now = DateTime.now();
+    final startOfWeek = now.subtract(Duration(days: now.weekday - 1));
+    
+    return List.generate(7, (index) {
+      final date = startOfWeek.add(Duration(days: index));
+      final baseTime = 20000 + (index * 500); // 每天略有不同
+      
+      return DailyStats(
+        date: date,
+        totalTime: baseTime,
+        workTime: (baseTime * 0.6).round(), // 60% 工作时间
+        studyTime: (baseTime * 0.15).round(), // 15% 学习时间
+        entertainmentTime: (baseTime * 0.15).round(), // 15% 娱乐时间
+        socialTime: (baseTime * 0.08).round(), // 8% 社交时间
+        toolTime: (baseTime * 0.02).round(), // 2% 工具时间
+        efficiencyScore: 65 + (index * 2), // 效率评分递增
+        focusScore: 60 + (index * 3),
+        appSwitchCount: 40 + (index * 2),
+        createdAt: DateTime.now(),
+        updatedAt: DateTime.now(),
+      );
+    });
+  }
+
+  /// 生成今日 Top 应用测试数据
+  static List<AppUsage> generateTopApps() {
+    final now = DateTime.now();
+    
+    return [
+      AppUsage(
+        packageName: 'com.google.chrome',
+        appName: 'Chrome',
+        startTime: now.subtract(const Duration(hours: 2, minutes: 15)),
+        endTime: now,
+        duration: 8100, // 2小时15分钟
+        category: 'work',
+        createdAt: now,
+        updatedAt: now,
+      ),
+      AppUsage(
+        packageName: 'com.microsoft.vscode',
+        appName: 'VS Code',
+        startTime: now.subtract(const Duration(hours: 1, minutes: 30)),
+        endTime: now,
+        duration: 5400, // 1小时30分钟
+        category: 'work',
+        createdAt: now,
+        updatedAt: now,
+      ),
+      AppUsage(
+        packageName: 'com.slack',
+        appName: 'Slack',
+        startTime: now.subtract(const Duration(hours: 1)),
+        endTime: now,
+        duration: 3600, // 1小时
+        category: 'work',
+        createdAt: now,
+        updatedAt: now,
+      ),
+      AppUsage(
+        packageName: 'com.notion',
+        appName: 'Notion',
+        startTime: now.subtract(const Duration(minutes: 45)),
+        endTime: now,
+        duration: 2700, // 45分钟
+        category: 'work',
+        createdAt: now,
+        updatedAt: now,
+      ),
+      AppUsage(
+        packageName: 'com.apple.mail',
+        appName: 'Mail',
+        startTime: now.subtract(const Duration(minutes: 30)),
+        endTime: now,
+        duration: 1800, // 30分钟
+        category: 'work',
+        createdAt: now,
+        updatedAt: now,
+      ),
+    ];
+  }
+
+  /// 检查是否应该使用测试数据
+  static bool shouldUseMockData() {
+    return kIsWeb;
+  }
+}
+

lib/services/statistics_service.dart

@@ -0,0 +1,199 @@
+import 'package:flutter/foundation.dart' show kIsWeb;
+import '../models/daily_stats.dart';
+import '../models/app_usage.dart';
+import '../database/app_usage_dao.dart';
+import '../database/daily_stats_dao.dart';
+import 'mock_data_service.dart';
+
+class StatisticsService {
+  final AppUsageDao _appUsageDao = AppUsageDao();
+  final DailyStatsDao _dailyStatsDao = DailyStatsDao();
+
+  // 获取今日统计（如果不存在则计算）
+  Future<DailyStats> getTodayStats() async {
+    // Web 平台返回测试数据
+    if (kIsWeb) {
+      return MockDataService.generateTodayStats();
+    }
+
+    final today = DateTime.now();
+    
+    // 先查数据库
+    var stats = await _dailyStatsDao.getTodayStats();
+    if (stats != null) {
+      return stats;
+    }
+
+    // 如果不存在，计算并保存
+    stats = await _calculateDailyStats(today);
+    if (stats != null) {
+      await _dailyStatsDao.upsertDailyStats(stats);
+    } else {
+      // 如果没有数据，返回空统计
+      stats = DailyStats(
+        date: today,
+        totalTime: 0,
+        createdAt: DateTime.now(),
+        updatedAt: DateTime.now(),
+      );
+    }
+
+    return stats;
+  }
+
+  // 计算指定日期的统计
+  Future<DailyStats?> _calculateDailyStats(DateTime date) async {
+    final startOfDay = DateTime(date.year, date.month, date.day);
+    final endOfDay = startOfDay.add(const Duration(days: 1));
+
+    // 获取该日期的所有应用使用记录
+    final appUsages = await _appUsageDao.getAppUsages(
+      startTime: startOfDay,
+      endTime: endOfDay,
+    );
+
+    if (appUsages.isEmpty) return null;
+
+    // 按分类聚合
+    final categoryTime = <String, int>{};
+    int totalTime = 0;
+    int appSwitchCount = 0;
+
+    for (final usage in appUsages) {
+      categoryTime[usage.category] = (categoryTime[usage.category] ?? 0) + usage.duration;
+      totalTime += usage.duration;
+      appSwitchCount += usage.deviceUnlockCount;
+    }
+
+    // 计算效率评分
+    final efficiencyScore = _calculateEfficiencyScore(categoryTime, totalTime);
+
+    // 计算专注度评分
+    final focusScore = _calculateFocusScore(appSwitchCount, totalTime);
+
+    return DailyStats(
+      date: startOfDay,
+      totalTime: totalTime,
+      workTime: categoryTime['work'] ?? 0,
+      studyTime: categoryTime['study'] ?? 0,
+      entertainmentTime: categoryTime['entertainment'] ?? 0,
+      socialTime: categoryTime['social'] ?? 0,
+      toolTime: categoryTime['tool'] ?? 0,
+      efficiencyScore: efficiencyScore,
+      focusScore: focusScore,
+      appSwitchCount: appSwitchCount,
+      createdAt: DateTime.now(),
+      updatedAt: DateTime.now(),
+    );
+  }
+
+  // 计算效率评分
+  int _calculateEfficiencyScore(Map<String, int> categoryTime, int totalTime) {
+    if (totalTime == 0) return 0;
+
+    // 工作时间占比（40%）
+    final workRatio = (categoryTime['work'] ?? 0) / totalTime;
+    final workScore = workRatio * 40;
+
+    // 学习时间占比（30%）
+    final studyRatio = (categoryTime['study'] ?? 0) / totalTime;
+    final studyScore = studyRatio * 30;
+
+    // 娱乐时间占比（越低越好，30%）
+    final entertainmentRatio = (categoryTime['entertainment'] ?? 0) / totalTime;
+    final entertainmentScore = (1 - entertainmentRatio) * 30;
+
+    return (workScore + studyScore + entertainmentScore).round();
+  }
+
+  // 计算专注度评分
+  int _calculateFocusScore(int appSwitchCount, int totalTime) {
+    if (totalTime == 0) return 0;
+
+    // 平均每小时切换次数
+    final switchesPerHour = (appSwitchCount / (totalTime / 3600));
+    
+    // 理想情况：每小时切换 < 10 次 = 100分
+    // 每小时切换 > 50 次 = 0分
+    final score = 100 - (switchesPerHour * 2).clamp(0, 100);
+    
+    return score.round();
+  }
+
+  // 获取本周统计
+  Future<List<DailyStats>> getWeekStats() async {
+    // Web 平台返回测试数据
+    if (kIsWeb) {
+      return MockDataService.generateWeekStats();
+    }
+
+    final stats = await _dailyStatsDao.getWeekStats();
+    
+    // 如果数据不完整，计算缺失的日期
+    final now = DateTime.now();
+    final startOfWeek = now.subtract(Duration(days: now.weekday - 1));
+    
+    final result = <DailyStats>[];
+    for (int i = 0; i < 7; i++) {
+      final date = startOfWeek.add(Duration(days: i));
+      final existing = stats.firstWhere(
+        (s) => s.date.year == date.year && 
+               s.date.month == date.month && 
+               s.date.day == date.day,
+        orElse: () => DailyStats(
+          date: date,
+          totalTime: 0,
+          createdAt: DateTime.now(),
+          updatedAt: DateTime.now(),
+        ),
+      );
+      result.add(existing);
+    }
+    
+    return result;
+  }
+
+  // 获取本月统计
+  Future<List<DailyStats>> getMonthStats() async {
+    return await _dailyStatsDao.getMonthStats();
+  }
+
+  // 刷新今日统计（重新计算）
+  Future<DailyStats> refreshTodayStats() async {
+    final today = DateTime.now();
+    final stats = await _calculateDailyStats(today);
+    
+    if (stats != null) {
+      await _dailyStatsDao.upsertDailyStats(stats);
+      return stats;
+    } else {
+      final emptyStats = DailyStats(
+        date: today,
+        totalTime: 0,
+        createdAt: DateTime.now(),
+        updatedAt: DateTime.now(),
+      );
+      await _dailyStatsDao.upsertDailyStats(emptyStats);
+      return emptyStats;
+    }
+  }
+
+  // 获取 Top 应用
+  Future<List<AppUsage>> getTopApps({
+    required DateTime startTime,
+    required DateTime endTime,
+    int limit = 10,
+  }) async {
+    // Web 平台返回测试数据
+    if (kIsWeb) {
+      return MockDataService.generateTopApps().take(limit).toList();
+    }
+
+    return await _appUsageDao.getTopApps(
+      startTime: startTime,
+      endTime: endTime,
+      limit: limit,
+    );
+  }
+}
+

lib/services/time_tracking_service.dart

@@ -0,0 +1,182 @@
+import 'package:flutter/services.dart';
+import '../models/app_usage.dart';
+import '../database/app_usage_dao.dart';
+import 'category_service.dart';
+import 'statistics_service.dart';
+
+class TimeTrackingService {
+  static const MethodChannel _channel = MethodChannel('autotime_tracker/time_tracking');
+  
+  final AppUsageDao _appUsageDao = AppUsageDao();
+  final CategoryService _categoryService = CategoryService();
+  final StatisticsService _statisticsService = StatisticsService();
+
+  /// 检查权限状态
+  Future<bool> hasPermission() async {
+    try {
+      final result = await _channel.invokeMethod<bool>('hasPermission');
+      return result ?? false;
+    } catch (e) {
+      print('Error checking permission: $e');
+      return false;
+    }
+  }
+
+  /// 请求权限
+  Future<bool> requestPermission() async {
+    try {
+      final result = await _channel.invokeMethod<bool>('requestPermission');
+      return result ?? false;
+    } catch (e) {
+      print('Error requesting permission: $e');
+      return false;
+    }
+  }
+
+  /// 获取应用使用数据（从系统 API）
+  Future<List<AppUsageData>> getAppUsageFromSystem({
+    required DateTime startTime,
+    required DateTime endTime,
+  }) async {
+    try {
+      final result = await _channel.invokeMethod<List<dynamic>>('getAppUsage', {
+        'startTime': startTime.millisecondsSinceEpoch,
+        'endTime': endTime.millisecondsSinceEpoch,
+      });
+
+      if (result == null) return [];
+
+      return result
+          .map((item) => AppUsageData.fromMap(Map<String, dynamic>.from(item)))
+          .toList();
+    } catch (e) {
+      print('Error getting app usage from system: $e');
+      return [];
+    }
+  }
+
+  /// 同步应用使用数据到数据库
+  Future<void> syncAppUsageToDatabase({
+    required DateTime startTime,
+    required DateTime endTime,
+  }) async {
+    try {
+      // 1. 从系统获取数据
+      final systemData = await getAppUsageFromSystem(
+        startTime: startTime,
+        endTime: endTime,
+      );
+
+      if (systemData.isEmpty) {
+        print('No app usage data from system');
+        return;
+      }
+
+      // 2. 转换为 AppUsage 模型并分类
+      final appUsages = <AppUsage>[];
+      for (final data in systemData) {
+        // 获取分类
+        final category = await _categoryService.getCategory(data.packageName);
+
+        // 创建 AppUsage 对象
+        final usage = AppUsage(
+          packageName: data.packageName,
+          appName: data.appName,
+          startTime: data.startTime,
+          endTime: data.endTime,
+          duration: data.duration,
+          category: category,
+          deviceUnlockCount: data.deviceUnlockCount ?? 0,
+          createdAt: DateTime.now(),
+          updatedAt: DateTime.now(),
+        );
+
+        appUsages.add(usage);
+      }
+
+      // 3. 批量插入数据库
+      if (appUsages.isNotEmpty) {
+        await _appUsageDao.batchInsertAppUsages(appUsages);
+        print('Synced ${appUsages.length} app usage records to database');
+      }
+
+      // 4. 更新今日统计
+      await _statisticsService.refreshTodayStats();
+    } catch (e) {
+      print('Error syncing app usage to database: $e');
+      rethrow;
+    }
+  }
+
+  /// 同步今日数据
+  Future<void> syncTodayData() async {
+    final now = DateTime.now();
+    final startOfDay = DateTime(now.year, now.month, now.day);
+    final endOfDay = startOfDay.add(const Duration(days: 1));
+
+    await syncAppUsageToDatabase(
+      startTime: startOfDay,
+      endTime: endOfDay,
+    );
+  }
+
+  /// 启动后台追踪
+  Future<void> startBackgroundTracking() async {
+    try {
+      await _channel.invokeMethod('startBackgroundTracking');
+    } catch (e) {
+      print('Error starting background tracking: $e');
+    }
+  }
+
+  /// 停止后台追踪
+  Future<void> stopBackgroundTracking() async {
+    try {
+      await _channel.invokeMethod('stopBackgroundTracking');
+    } catch (e) {
+      print('Error stopping background tracking: $e');
+    }
+  }
+
+  /// 检查后台追踪状态
+  Future<bool> isBackgroundTrackingActive() async {
+    try {
+      final result = await _channel.invokeMethod<bool>('isBackgroundTrackingActive');
+      return result ?? false;
+    } catch (e) {
+      print('Error checking background tracking status: $e');
+      return false;
+    }
+  }
+}
+
+/// 系统返回的应用使用数据模型
+class AppUsageData {
+  final String packageName;
+  final String appName;
+  final DateTime startTime;
+  final DateTime endTime;
+  final int duration; // 秒
+  final int? deviceUnlockCount;
+
+  AppUsageData({
+    required this.packageName,
+    required this.appName,
+    required this.startTime,
+    required this.endTime,
+    required this.duration,
+    this.deviceUnlockCount,
+  });
+
+  factory AppUsageData.fromMap(Map<String, dynamic> map) {
+    return AppUsageData(
+      packageName: map['packageName'] as String,
+      appName: map['appName'] as String,
+      startTime: DateTime.fromMillisecondsSinceEpoch(map['startTime'] as int),
+      endTime: DateTime.fromMillisecondsSinceEpoch(map['endTime'] as int),
+      duration: map['duration'] as int,
+      deviceUnlockCount: map['deviceUnlockCount'] as int?,
+    );
+  }
+}
+

lib/theme/app_theme.dart

@@ -0,0 +1,119 @@
+import 'package:flutter/material.dart';
+import 'package:google_fonts/google_fonts.dart';
+
+class AppTheme {
+  // 颜色系统
+  static const Color primaryColor = Color(0xFF6366F1); // Indigo
+  static const Color secondaryColor = Color(0xFF8B5CF6); // Purple
+  static const Color accentColor = Color(0xFF10B981); // Green
+
+  // 分类颜色
+  static const Color workColor = Color(0xFF6366F1); // Indigo
+  static const Color studyColor = Color(0xFF8B5CF6); // Purple
+  static const Color entertainmentColor = Color(0xFFF59E0B); // Orange
+  static const Color socialColor = Color(0xFFEC4899); // Pink
+  static const Color toolColor = Color(0xFF6B7280); // Gray
+
+  // 状态颜色
+  static const Color successColor = Color(0xFF10B981);
+  static const Color warningColor = Color(0xFFF59E0B);
+  static const Color errorColor = Color(0xFFEF4444);
+  static const Color infoColor = Color(0xFF3B82F6);
+
+  // 浅色主题
+  static ThemeData get lightTheme {
+    return ThemeData(
+      useMaterial3: true,
+      colorScheme: ColorScheme.fromSeed(
+        seedColor: primaryColor,
+        brightness: Brightness.light,
+      ),
+      textTheme: GoogleFonts.interTextTheme(),
+      scaffoldBackgroundColor: Colors.white,
+      cardTheme: CardThemeData(
+        elevation: 0,
+        shape: RoundedRectangleBorder(
+          borderRadius: BorderRadius.circular(12),
+        ),
+        color: Colors.grey[50],
+      ),
+      appBarTheme: AppBarTheme(
+        elevation: 0,
+        backgroundColor: Colors.white,
+        foregroundColor: Colors.black87,
+        titleTextStyle: GoogleFonts.inter(
+          fontSize: 18,
+          fontWeight: FontWeight.w600,
+          color: Colors.black87,
+        ),
+      ),
+    );
+  }
+
+  // 深色主题
+  static ThemeData get darkTheme {
+    return ThemeData(
+      useMaterial3: true,
+      colorScheme: ColorScheme.fromSeed(
+        seedColor: primaryColor,
+        brightness: Brightness.dark,
+      ),
+      textTheme: GoogleFonts.interTextTheme(ThemeData.dark().textTheme),
+      scaffoldBackgroundColor: const Color(0xFF1F2937),
+      cardTheme: CardThemeData(
+        elevation: 0,
+        shape: RoundedRectangleBorder(
+          borderRadius: BorderRadius.circular(12),
+        ),
+        color: const Color(0xFF374151),
+      ),
+      appBarTheme: AppBarTheme(
+        elevation: 0,
+        backgroundColor: const Color(0xFF1F2937),
+        foregroundColor: Colors.white,
+        titleTextStyle: GoogleFonts.inter(
+          fontSize: 18,
+          fontWeight: FontWeight.w600,
+          color: Colors.white,
+        ),
+      ),
+    );
+  }
+
+  // 获取分类颜色
+  static Color getCategoryColor(String category) {
+    switch (category.toLowerCase()) {
+      case 'work':
+        return workColor;
+      case 'study':
+        return studyColor;
+      case 'entertainment':
+        return entertainmentColor;
+      case 'social':
+        return socialColor;
+      case 'tool':
+        return toolColor;
+      default:
+        return Colors.grey;
+    }
+  }
+
+  // 获取分类中文名称
+  static String getCategoryName(String category) {
+    switch (category.toLowerCase()) {
+      case 'work':
+        return '工作';
+      case 'study':
+        return '学习';
+      case 'entertainment':
+        return '娱乐';
+      case 'social':
+        return '社交';
+      case 'tool':
+        return '工具';
+      default:
+        return '其他';
+    }
+  }
+}
+

lib/widgets/custom_time_picker_dialog.dart

@@ -0,0 +1,241 @@
+import 'package:flutter/material.dart';
+
+/// 自定义时间选择器对话框
+/// 用于选择小时和分钟，不会自动切换选择模式
+class CustomTimePickerDialog extends StatefulWidget {
+  final String title;
+  final TimeOfDay initialTime;
+
+  const CustomTimePickerDialog({
+    super.key,
+    required this.title,
+    required this.initialTime,
+  });
+
+  @override
+  State<CustomTimePickerDialog> createState() => _CustomTimePickerDialogState();
+
+  /// 显示时间选择器对话框
+  static Future<TimeOfDay?> show({
+    required BuildContext context,
+    required String title,
+    required TimeOfDay initialTime,
+  }) async {
+    return await showDialog<TimeOfDay>(
+      context: context,
+      builder: (context) => CustomTimePickerDialog(
+        title: title,
+        initialTime: initialTime,
+      ),
+    );
+  }
+}
+
+class _CustomTimePickerDialogState extends State<CustomTimePickerDialog> {
+  late int _hours;
+  late int _minutes;
+
+  @override
+  void initState() {
+    super.initState();
+    _hours = widget.initialTime.hour;
+    _minutes = widget.initialTime.minute;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return AlertDialog(
+      title: Text(widget.title),
+      content: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Row(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              // 小时选择
+              Column(
+                children: [
+                  Text('小时', style: theme.textTheme.bodySmall),
+                  const SizedBox(height: 8),
+                  Row(
+                    children: [
+                      IconButton(
+                        icon: const Icon(Icons.remove_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            if (_hours > 0) {
+                              _hours--;
+                            } else {
+                              _hours = 23;
+                            }
+                          });
+                        },
+                      ),
+                      Container(
+                        width: 60,
+                        padding: const EdgeInsets.symmetric(vertical: 8),
+                        decoration: BoxDecoration(
+                          color: theme.colorScheme.primaryContainer.withOpacity(0.3),
+                          borderRadius: BorderRadius.circular(8),
+                        ),
+                        child: Text(
+                          '$_hours',
+                          textAlign: TextAlign.center,
+                          style: theme.textTheme.headlineMedium?.copyWith(
+                            fontWeight: FontWeight.bold,
+                          ),
+                        ),
+                      ),
+                      IconButton(
+                        icon: const Icon(Icons.add_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            if (_hours < 23) {
+                              _hours++;
+                            } else {
+                              _hours = 0;
+                            }
+                          });
+                        },
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+              const SizedBox(width: 24),
+              // 分隔符
+              Text(
+                ':',
+                style: theme.textTheme.headlineLarge?.copyWith(
+                  fontWeight: FontWeight.bold,
+                ),
+              ),
+              const SizedBox(width: 24),
+              // 分钟选择
+              Column(
+                children: [
+                  Text('分钟', style: theme.textTheme.bodySmall),
+                  const SizedBox(height: 8),
+                  Row(
+                    children: [
+                      IconButton(
+                        icon: const Icon(Icons.remove_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            if (_minutes >= 15) {
+                              _minutes -= 15;
+                            } else if (_minutes > 0) {
+                              _minutes = 0;
+                            } else {
+                              _minutes = 45;
+                            }
+                          });
+                        },
+                      ),
+                      Container(
+                        width: 60,
+                        padding: const EdgeInsets.symmetric(vertical: 8),
+                        decoration: BoxDecoration(
+                          color: theme.colorScheme.secondaryContainer.withOpacity(0.3),
+                          borderRadius: BorderRadius.circular(8),
+                        ),
+                        child: Text(
+                          _minutes.toString().padLeft(2, '0'),
+                          textAlign: TextAlign.center,
+                          style: theme.textTheme.headlineMedium?.copyWith(
+                            fontWeight: FontWeight.bold,
+                          ),
+                        ),
+                      ),
+                      IconButton(
+                        icon: const Icon(Icons.add_circle_outline),
+                        onPressed: () {
+                          setState(() {
+                            _minutes += 15;
+                            if (_minutes >= 60) {
+                              _minutes = 0;
+                            }
+                          });
+                        },
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+            ],
+          ),
+          const SizedBox(height: 16),
+          // 快速选择按钮
+          Wrap(
+            spacing: 8,
+            runSpacing: 8,
+            alignment: WrapAlignment.center,
+            children: [
+              _buildQuickTimeButton(context, theme, '00:00', 0, 0),
+              _buildQuickTimeButton(context, theme, '08:00', 8, 0),
+              _buildQuickTimeButton(context, theme, '12:00', 12, 0),
+              _buildQuickTimeButton(context, theme, '18:00', 18, 0),
+              _buildQuickTimeButton(context, theme, '20:00', 20, 0),
+              _buildQuickTimeButton(context, theme, '22:00', 22, 0),
+            ],
+          ),
+        ],
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.of(context).pop(),
+          child: const Text('取消'),
+        ),
+        ElevatedButton(
+          onPressed: () {
+            Navigator.of(context).pop(
+              TimeOfDay(hour: _hours, minute: _minutes),
+            );
+          },
+          child: const Text('确定'),
+        ),
+      ],
+    );
+  }
+
+  Widget _buildQuickTimeButton(
+    BuildContext context,
+    ThemeData theme,
+    String label,
+    int hours,
+    int minutes,
+  ) {
+    final isSelected = _hours == hours && _minutes == minutes;
+    return OutlinedButton(
+      onPressed: () {
+        setState(() {
+          _hours = hours;
+          _minutes = minutes;
+        });
+      },
+      style: OutlinedButton.styleFrom(
+        backgroundColor: isSelected
+            ? theme.colorScheme.primaryContainer.withOpacity(0.3)
+            : null,
+        side: BorderSide(
+          color: isSelected
+              ? theme.colorScheme.primary
+              : theme.colorScheme.outline.withOpacity(0.5),
+          width: isSelected ? 2 : 1,
+        ),
+      ),
+      child: Text(
+        label,
+        style: TextStyle(
+          fontSize: 12,
+          color: isSelected
+              ? theme.colorScheme.primary
+              : theme.colorScheme.onSurface,
+        ),
+      ),
+    );
+  }
+}
+

lib/widgets/empty_state_widget.dart

@@ -0,0 +1,149 @@
+import 'package:flutter/material.dart';
+import '../theme/app_theme.dart';
+
+/// 空状态组件
+/// 用于显示无数据时的友好提示
+class EmptyStateWidget extends StatelessWidget {
+  final IconData icon;
+  final String title;
+  final String? subtitle;
+  final String? actionLabel;
+  final VoidCallback? onAction;
+  final bool showIllustration;
+
+  const EmptyStateWidget({
+    super.key,
+    required this.icon,
+    required this.title,
+    this.subtitle,
+    this.actionLabel,
+    this.onAction,
+    this.showIllustration = true,
+  });
+
+  /// 默认空状态 - 无数据
+  factory EmptyStateWidget.noData({
+    String? title,
+    String? subtitle,
+    String? actionLabel,
+    VoidCallback? onAction,
+  }) {
+    return EmptyStateWidget(
+      icon: Icons.inbox_outlined,
+      title: title ?? '暂无数据',
+      subtitle: subtitle ?? '使用应用一段时间后，数据将显示在这里',
+      actionLabel: actionLabel,
+      onAction: onAction,
+    );
+  }
+
+  /// 空状态 - 无搜索结果
+  factory EmptyStateWidget.noSearchResults({
+    String? query,
+  }) {
+    return EmptyStateWidget(
+      icon: Icons.search_off,
+      title: '未找到匹配结果',
+      subtitle: query != null ? '没有找到与 "$query" 相关的内容' : '请尝试其他关键词',
+      showIllustration: false,
+    );
+  }
+
+  /// 空状态 - 无应用数据
+  factory EmptyStateWidget.noApps({
+    VoidCallback? onAction,
+  }) {
+    return EmptyStateWidget(
+      icon: Icons.apps_outlined,
+      title: '暂无应用数据',
+      subtitle: '使用应用一段时间后，应用使用记录将显示在这里',
+      actionLabel: '刷新',
+      onAction: onAction,
+    );
+  }
+
+  /// 空状态 - 首次使用
+  factory EmptyStateWidget.firstTime({
+    VoidCallback? onAction,
+  }) {
+    return EmptyStateWidget(
+      icon: Icons.touch_app,
+      title: '欢迎使用 AutoTime Tracker',
+      subtitle: '开始追踪您的时间使用情况\n\n1. 授予应用使用权限\n2. 正常使用您的设备\n3. 查看详细的使用统计',
+      actionLabel: '去设置权限',
+      onAction: onAction,
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(32),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            if (showIllustration) ...[
+              Container(
+                width: 120,
+                height: 120,
+                decoration: BoxDecoration(
+                  color: AppTheme.primaryColor.withOpacity(0.1),
+                  shape: BoxShape.circle,
+                ),
+                child: Icon(
+                  icon,
+                  size: 64,
+                  color: AppTheme.primaryColor.withOpacity(0.6),
+                ),
+              ),
+              const SizedBox(height: 24),
+            ] else ...[
+              Icon(
+                icon,
+                size: 64,
+                color: theme.colorScheme.onSurface.withOpacity(0.3),
+              ),
+              const SizedBox(height: 16),
+            ],
+            Text(
+              title,
+              style: theme.textTheme.titleLarge?.copyWith(
+                fontWeight: FontWeight.w600,
+                color: theme.colorScheme.onSurface,
+              ),
+              textAlign: TextAlign.center,
+            ),
+            if (subtitle != null) ...[
+              const SizedBox(height: 12),
+              Text(
+                subtitle!,
+                style: theme.textTheme.bodyMedium?.copyWith(
+                  color: theme.colorScheme.onSurface.withOpacity(0.6),
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ],
+            if (actionLabel != null && onAction != null) ...[
+              const SizedBox(height: 24),
+              ElevatedButton.icon(
+                onPressed: onAction,
+                icon: const Icon(Icons.refresh),
+                label: Text(actionLabel!),
+                style: ElevatedButton.styleFrom(
+                  padding: const EdgeInsets.symmetric(
+                    horizontal: 24,
+                    vertical: 12,
+                  ),
+                ),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}
+

lib/widgets/error_state_widget.dart

@@ -0,0 +1,141 @@
+import 'package:flutter/material.dart';
+import '../theme/app_theme.dart';
+
+/// 错误状态组件
+/// 用于显示错误时的友好提示
+class ErrorStateWidget extends StatelessWidget {
+  final String? title;
+  final String? message;
+  final String? actionLabel;
+  final VoidCallback? onRetry;
+  final IconData icon;
+  final bool showDetails;
+
+  const ErrorStateWidget({
+    super.key,
+    this.title,
+    this.message,
+    this.actionLabel,
+    this.onRetry,
+    this.icon = Icons.error_outline,
+    this.showDetails = false,
+  });
+
+  /// 默认错误状态
+  factory ErrorStateWidget.generic({
+    String? message,
+    VoidCallback? onRetry,
+  }) {
+    return ErrorStateWidget(
+      title: '加载失败',
+      message: message ?? '请检查网络连接后重试',
+      actionLabel: '重试',
+      onRetry: onRetry,
+    );
+  }
+
+  /// 权限错误
+  factory ErrorStateWidget.permission({
+    VoidCallback? onRetry,
+  }) {
+    return ErrorStateWidget(
+      icon: Icons.security,
+      title: '权限未授予',
+      message: '需要授予应用使用权限才能追踪时间\n\n请在系统设置中开启"使用情况访问权限"',
+      actionLabel: '去设置',
+      onRetry: onRetry,
+    );
+  }
+
+  /// 网络错误
+  factory ErrorStateWidget.network({
+    VoidCallback? onRetry,
+  }) {
+    return ErrorStateWidget(
+      icon: Icons.wifi_off,
+      title: '网络连接失败',
+      message: '无法连接到服务器\n\n请检查网络连接后重试',
+      actionLabel: '重试',
+      onRetry: onRetry,
+    );
+  }
+
+  /// 数据加载错误
+  factory ErrorStateWidget.dataLoad({
+    String? message,
+    VoidCallback? onRetry,
+  }) {
+    return ErrorStateWidget(
+      icon: Icons.cloud_off,
+      title: '数据加载失败',
+      message: message ?? '无法加载数据，请稍后重试',
+      actionLabel: '重试',
+      onRetry: onRetry,
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(32),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Container(
+              width: 100,
+              height: 100,
+              decoration: BoxDecoration(
+                color: AppTheme.errorColor.withOpacity(0.1),
+                shape: BoxShape.circle,
+              ),
+              child: Icon(
+                icon,
+                size: 56,
+                color: AppTheme.errorColor,
+              ),
+            ),
+            const SizedBox(height: 24),
+            Text(
+              title ?? '出错了',
+              style: theme.textTheme.titleLarge?.copyWith(
+                fontWeight: FontWeight.w600,
+                color: theme.colorScheme.error,
+              ),
+              textAlign: TextAlign.center,
+            ),
+            if (message != null) ...[
+              const SizedBox(height: 12),
+              Text(
+                message!,
+                style: theme.textTheme.bodyMedium?.copyWith(
+                  color: theme.colorScheme.onSurface.withOpacity(0.7),
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ],
+            if (actionLabel != null && onRetry != null) ...[
+              const SizedBox(height: 24),
+              ElevatedButton.icon(
+                onPressed: onRetry,
+                icon: const Icon(Icons.refresh),
+                label: Text(actionLabel!),
+                style: ElevatedButton.styleFrom(
+                  backgroundColor: AppTheme.errorColor,
+                  foregroundColor: Colors.white,
+                  padding: const EdgeInsets.symmetric(
+                    horizontal: 24,
+                    vertical: 12,
+                  ),
+                ),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}
+