首次提交：关于页、夜间模式选项

lib/main.dart

@@ -1,12 +1,11 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'pages/battery_health_page.dart';
 import 'services/saf_storage_service.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
-
   await SafStorageService().init();
-
   runApp(const MyApp());
 }
 
@@ -17,51 +16,65 @@ class MyApp extends StatelessWidget {
   Widget build(BuildContext context) {
     return MaterialApp(
       title: '电池健康度',
-      theme: ThemeData(
-        // 🟢 中文用 HarmonyOS Sans SC
-        fontFamily: 'HarmonyOS_Sans_SC',
-        // 🟢 数字回退到 FlymeFont
-        fontFamilyFallback: const ['Flyme'],
-        // 🟢 统一文字颜色为黑色
-        colorScheme: ColorScheme.fromSeed(
-          seedColor: const Color(0xFFFFFFFF),
-        ).copyWith(onSurface: Colors.black),
-        textTheme: const TextTheme(
-          // 大标题/数字（健康度、容量等）
-          displayMedium: TextStyle(
-            fontFamily: 'HarmonyOS_Sans_SC',
-            fontFamilyFallback: ['Flyme'],
-            color: Colors.black,
-          ),
-          // 标题（如“容量百分比变动趋势”）
-          headlineMedium: TextStyle(
-            fontFamily: 'HarmonyOS_Sans_SC',
-            fontFamilyFallback: ['Flyme'],
-            color: Colors.black,
-          ),
-          // 正文（电压、温度、循环次数等）
-          bodyMedium: TextStyle(
-            fontFamily: 'HarmonyOS_Sans_SC',
-            fontFamilyFallback: ['Flyme'],
-            color: Colors.black,
-          ),
-          // 小字（日期、辅助信息）
-          bodySmall: TextStyle(
-            fontFamily: 'HarmonyOS_Sans_SC',
-            fontFamilyFallback: ['Flyme'],
-            color: Colors.black87,
-          ),
-          // 数字专用（大号数字，如健康度百分比）
-          displayLarge: TextStyle(
-            fontFamily: 'HarmonyOS_Sans_SC',
-            fontFamilyFallback: ['Flyme'],
-            color: Colors.black,
-          ),
-        ),
-        useMaterial3: true,
-      ),
+      theme: _lightTheme(),
+      darkTheme: _darkTheme(),
+      themeMode: ThemeMode.system, // 默认跟随系统
       home: const BatteryHealthPage(),
       debugShowCheckedModeBanner: false,
     );
   }
+
+  ThemeData _lightTheme() {
+    return ThemeData(
+      fontFamily: 'HarmonyOS_Sans_SC',
+      fontFamilyFallback: const ['Flyme'],
+      useMaterial3: true,
+      brightness: Brightness.light,
+      scaffoldBackgroundColor: Colors.white,
+      appBarTheme: const AppBarTheme(
+        backgroundColor: Colors.white,
+        foregroundColor: Colors.black,
+        elevation: 0,
+        centerTitle: false,
+      ),
+      iconTheme: const IconThemeData(color: Colors.black),
+      colorScheme: const ColorScheme.light(
+        primary: Color(0xFF1A73E8),
+        secondary: Color(0xFF1A73E8),
+      ),
+      textTheme: const TextTheme(
+        bodyLarge: TextStyle(color: Colors.black),
+        bodyMedium: TextStyle(color: Colors.black87),
+        labelLarge: TextStyle(color: Colors.black),
+      ),
+      dividerColor: Colors.grey.shade200,
+    );
+  }
+
+  ThemeData _darkTheme() {
+    return ThemeData(
+      fontFamily: 'HarmonyOS_Sans_SC',
+      fontFamilyFallback: const ['Flyme'],
+      useMaterial3: true,
+      brightness: Brightness.dark,
+      scaffoldBackgroundColor: const Color(0xFF121212),
+      appBarTheme: const AppBarTheme(
+        backgroundColor: Color(0xFF1E1E1E),
+        foregroundColor: Colors.white,
+        elevation: 0,
+        centerTitle: false,
+      ),
+      iconTheme: const IconThemeData(color: Colors.white),
+      colorScheme: const ColorScheme.dark(
+        primary: Color(0xFF4FC3F7),
+        secondary: Color(0xFF4FC3F7),
+      ),
+      textTheme: const TextTheme(
+        bodyLarge: TextStyle(color: Colors.white),
+        bodyMedium: TextStyle(color: Colors.white70),
+        labelLarge: TextStyle(color: Colors.white),
+      ),
+      dividerColor: Colors.grey.shade800,
+    );
+  }
 }