content: import 'package:flutter/material.dart';
  import 'package:flutter_screenutil/flutter_screenutil.dart';
  
  /// 浅色主题
  ThemeData lightTheme = ThemeData(
    // 浅色背景
    brightness: Brightness.light,
    // 启用material3
    useMaterial3: true,
    // 文本主题
    // 定制好一些文本样式，后续直接使用,例如：`style: Theme.of(context).textTheme.bodySmall`
    // 否则就是默认的
    textTheme: TextTheme(
      displayLarge: TextStyle(
          fontSize: 96.sp, fontWeight: FontWeight.w300, color: Colors.black),
      displayMedium: TextStyle(
          fontSize: 60.sp, fontWeight: FontWeight.w400, color: Colors.black),
      displaySmall: TextStyle(
          fontSize: 48.sp, fontWeight: FontWeight.w400, color: Colors.black),
      headlineMedium: TextStyle(
          fontSize: 34.sp, fontWeight: FontWeight.w400, color: Colors.black),
      headlineSmall: TextStyle(
          fontSize: 24.sp, fontWeight: FontWeight.w400, color: Colors.black),
      titleLarge: TextStyle(
          fontSize: 20.sp, fontWeight: FontWeight.w500, color: Colors.black),
      bodyLarge: TextStyle(
          fontSize: 16.sp, fontWeight: FontWeight.w400, color: Colors.black87),
      bodyMedium: TextStyle(
          fontSize: 14.sp, fontWeight: FontWeight.w400, color: Colors.black87),
      bodySmall: TextStyle(
          fontSize: 12.sp, fontWeight: FontWeight.w400, color: Colors.black54),
      labelLarge: TextStyle(
          fontSize: 14.sp, fontWeight: FontWeight.w500, color: Colors.white),
    ),
    // appbar主题
    appBarTheme: AppBarTheme(
      // color: Colors.blue,
      iconTheme: const IconThemeData(color: Colors.white),
      titleTextStyle: TextStyle(fontSize: 20.sp),
    ),
    // 颜色组，定义应用可以使用的颜色集。定义了许多小部件的默认颜色
    colorScheme: ColorScheme.fromSeed(
      seedColor: Colors.red,
    ).copyWith(
      primary: Colors.green,
    ),
    // 指定某种按钮的主体
    elevatedButtonTheme: ElevatedButtonThemeData(
        style: ButtonStyle(
      backgroundColor: WidgetStateProperty.resolveWith<Color?>(
        (Set<WidgetState> states) => Colors.red,
      ),
    )),
  );
  
  final ThemeData darkTheme = ThemeData(
    useMaterial3: false,
    brightness: Brightness.light,
    primaryColor: Colors.greenAccent,
    canvasColor: Colors.yellow,
    cardColor: Colors.black,
    secondaryHeaderColor: Colors.grey,
    primarySwatch: Colors.red,
    textTheme: TextTheme(
      displayLarge: TextStyle(
        fontSize: 52.sp,
        fontWeight: FontWeight.w500,
      ),
      bodyLarge: TextStyle(fontSize: 18.sp),
    ),
  );
  