feat(home): 首页改为三列探索网格

lib/core/theme/app_colors.dart

@@ -60,6 +60,18 @@ abstract final class AppColors {
   /// 页面背景。
   static const ink = Color(0xFF0B1020);
 
+  /// 首页/追剧/我的统一的纯黑内容背景。
+  static const appBackground = Color(0xFF000000);
+
+  /// 中性深灰卡片与控件表面。
+  static const contentCard = Color(0xFF171717);
+  static const contentSurface = Color(0xFF1C1C1E);
+  static const contentChip = Color(0xFF2C2C2E);
+  static const contentBorder = Color(0x1AFFFFFF);
+
+  /// 次级文字与列表 chevron。
+  static const textSecondary = Color(0xFF8E8E93);
+
   /// 原生开屏与冷启动过渡底色。
   static const splashInk = ink;
 
@@ -125,7 +137,12 @@ abstract final class AppColors {
   static const badgeBeige = raised;
 
   /// 导航未选中。
-  static const navUnselected = Color(0xFF8E8E93);
+  static const navUnselected = textSecondary;
+
+  /// 首页内容角标。
+  static const badgeHot = Color(0xFFE5484D);
+  static const badgeNew = Color(0xFF3B82F6);
+  static const badgeAnime = Color(0xFF8B5CF6);
 
   /// 播放器次要文字。
   static const playerMuted = Color(0xA3FFFFFF);

lib/core/theme/app_dimens.dart

@@ -73,4 +73,18 @@ abstract final class AppDimens {
   static const double cardTitle = 15;
   static const double cardShadowBlur = 0;
   static const double cardShadowY = 0;
+
+  /// 首页探索网格。
+  static const double homeGridGap = 8;
+  static const double homeCardRadius = 8;
+  static const double homeCardPadding = 8;
+  static const double homeCardTitle = 13;
+  static const double homeCardMeta = 10;
+  static const double homeCardBadge = 9;
+  static const double homeTagFont = 10;
+  static const double homeCardBodyExtent = 84;
+  static const double homeSectionFont = 14;
+  static const double homeSectionIndicator = 2;
+  static const double homeIconSlot = 44;
+  static const double homeHeaderIcon = 22;
 }