diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index b9f2bc4..5ae6323 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -9,7 +9,8 @@
       "Bash(flutter run:*)",
       "Bash(timeout:*)",
       "Bash(nul)",
-      "Bash(start \"\" \"f:\\cursor-auto\\focusBuddy\\icon-preview.html\")"
+      "Bash(start \"\" \"f:\\cursor-auto\\focusBuddy\\icon-preview.html\")",
+      "Bash(dir:*)"
     ],
     "deny": [],
     "ask": []
diff --git a/ANDROID_BUILD_FIX.md b/ANDROID_BUILD_FIX.md
new file mode 100644
index 0000000..0429708
--- /dev/null
+++ b/ANDROID_BUILD_FIX.md
@@ -0,0 +1,140 @@
+# 🔧 Android 构建修复 - Core Library Desugaring
+
+**日期**: 2025-11-22
+**问题**: flutter_local_notifications 需要 core library desugaring
+
+---
+
+## ❌ 错误信息
+
+```
+FAILURE: Build failed with an exception.
+
+* What went wrong:
+Execution failed for task ':app:checkDebugAarMetadata'.
+> A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
+   > An issue was found when checking AAR metadata:
+
+       1.  Dependency ':flutter_local_notifications' requires core library desugaring to be enabled
+           for :app.
+```
+
+---
+
+## 🔍 问题原因
+
+`flutter_local_notifications` 包使用了 Java 8+ 的新 API（例如 `java.time` 包），这些 API 在较旧的 Android 版本上不可用。
+
+Core library desugaring 允许应用使用这些新 API，同时保持对旧版 Android 的兼容性。
+
+---
+
+## ✅ 解决方案
+
+修改 `android/app/build.gradle.kts` 文件：
+
+### 1. 启用 desugaring
+
+在 `compileOptions` 中添加：
+
+```kotlin
+compileOptions {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+    isCoreLibraryDesugaringEnabled = true  // ✨ 新增
+}
+```
+
+### 2. 添加 desugaring 库依赖
+
+在文件末尾添加：
+
+```kotlin
+dependencies {
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.0.4")
+}
+```
+
+---
+
+## 📝 完整修改
+
+### 修改前
+```kotlin
+compileOptions {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+}
+
+flutter {
+    source = "../.."
+}
+```
+
+### 修改后
+```kotlin
+compileOptions {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+    isCoreLibraryDesugaringEnabled = true  // ✨ 新增
+}
+
+flutter {
+    source = "../.."
+}
+
+dependencies {  // ✨ 新增
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.0.4")
+}
+```
+
+---
+
+## 🧪 验证修复
+
+运行以下命令测试：
+
+```bash
+flutter clean
+flutter build apk --debug
+```
+
+或直接运行：
+
+```bash
+flutter run -d <android-device>
+```
+
+---
+
+## 📚 相关信息
+
+### 什么是 Core Library Desugaring?
+
+Desugaring 是一个过程，它将使用较新 Java API 的代码转换为在旧版 Android 上可运行的等效代码。
+
+### 支持的 API
+
+启用 desugaring 后，可以使用：
+- `java.time.*` (日期和时间 API)
+- `java.util.stream.*` (Stream API)
+- `java.util.function.*` (函数式接口)
+- 以及其他 Java 8+ 的核心库 API
+
+### 版本说明
+
+- `desugar_jdk_libs:2.0.4` 是当前稳定版本
+- 最低支持 Android API 21 (Android 5.0)
+
+---
+
+## 🔗 参考链接
+
+- [Android Developer - Java 8+ Support](https://developer.android.com/studio/write/java8-support.html)
+- [Core Library Desugaring Guide](https://developer.android.com/studio/write/java8-support#library-desugaring)
+
+---
+
+**状态**: ✅ 已修复
+**文件**: `android/app/build.gradle.kts`
+**影响**: Android 构建现在应该可以正常工作
diff --git a/android/app/build.gradle.kts b/android/app/build.gradle.kts
index 27bc332..d27925c 100644
--- a/android/app/build.gradle.kts
+++ b/android/app/build.gradle.kts
@@ -13,6 +13,7 @@ android {
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_17
         targetCompatibility = JavaVersion.VERSION_17
+        isCoreLibraryDesugaringEnabled = true
     }
 
     kotlinOptions {
@@ -42,3 +43,7 @@ android {
 flutter {
     source = "../.."
 }
+
+dependencies {
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.0.4")
+}