深色模式、首页设置页面和功能优化

lib/widgets/tabbed_nav_app_bar.dart

@@ -4,7 +4,7 @@ import '../constants/app_constants.dart';
 /// 时间: 2026-03-22
 /// 功能: 主导航内「标题 + Tab」共用 AppBar 构造
 /// 介绍: 压缩工具栏与 Tab 行高度，关闭 M3 卷动 surface tint，统一收藏页与发现页顶部观感
-/// 最新变化: 初始提取，减少两页相同结构的顶部留白
+/// 最新变化: 2026-04-02 支持深色模式
 
 /// 主导航子页（IndexedStack 内）带 [TabBar] 的页面共用 [AppBar] 配置
 class TabbedNavAppBar {
@@ -19,19 +19,26 @@ class TabbedNavAppBar {
     bool tabBarScrollable = false,
     EdgeInsetsGeometry? tabPadding,
     EdgeInsetsGeometry? tabLabelPadding,
+    Color? backgroundColor,
+    Color? foregroundColor,
   }) {
+    final isDark = backgroundColor != null && backgroundColor != Colors.white;
+
     return AppBar(
       title: Text(
         title,
-        style: const TextStyle(
+        style: TextStyle(
           fontWeight: FontWeight.bold,
           fontSize: 18,
-          color: Colors.black87,
+          color: foregroundColor ?? (isDark ? Colors.white : Colors.black87),
         ),
       ),
-      backgroundColor: Colors.white,
-      foregroundColor: Colors.black87,
-      iconTheme: const IconThemeData(color: Colors.black87),
+      backgroundColor: backgroundColor ?? Colors.white,
+      foregroundColor:
+          foregroundColor ?? (isDark ? Colors.white : Colors.black87),
+      iconTheme: IconThemeData(
+        color: foregroundColor ?? (isDark ? Colors.white : Colors.black87),
+      ),
       elevation: 0,
       scrolledUnderElevation: 0,
       surfaceTintColor: Colors.transparent,
@@ -49,7 +56,7 @@ class TabbedNavAppBar {
         dividerColor: Colors.transparent,
         tabs: tabLabels.map((String e) => Tab(text: e)).toList(),
         labelColor: AppConstants.primaryColor,
-        unselectedLabelColor: Colors.grey[600],
+        unselectedLabelColor: isDark ? Colors.grey[400] : Colors.grey[600],
         indicator: UnderlineTabIndicator(
           borderSide: BorderSide(color: AppConstants.primaryColor, width: 3),
         ),