style: 增加推荐剧单渐变背景

test/recommend/recommend_sections_test.dart

@@ -143,6 +143,31 @@ void main() {
     expect(find.text('New This Week'), findsOneWidget);
     expect(find.text('Costume Drama Awards'), findsOneWidget);
     expect(find.byType(AppBottomNav), findsOneWidget);
+    final playlistSurface = tester.widget<DecoratedBox>(
+      find.byKey(const Key('recommend-playlist-surface')),
+    );
+    final playlistGradient =
+        (playlistSurface.decoration as BoxDecoration).gradient!
+            as LinearGradient;
+    expect(playlistGradient.begin, Alignment.topCenter);
+    expect(playlistGradient.end, Alignment.bottomCenter);
+    expect(playlistGradient.colors, const [
+      AppColors.mineGradientTop,
+      AppColors.mineGradientMiddle,
+      AppColors.mineGradientBottom,
+    ]);
+    expect(playlistGradient.stops, const [0, 0.4, 0.75]);
+    final playlistGlow = tester.widget<DecoratedBox>(
+      find.byKey(const Key('recommend-playlist-glow')),
+    );
+    final glowGradient =
+        (playlistGlow.decoration as BoxDecoration).gradient! as RadialGradient;
+    expect(glowGradient.center, const Alignment(0, -0.95));
+    expect(glowGradient.radius, 0.9);
+    expect(glowGradient.colors, const [
+      AppColors.recommendPlaylistGlow,
+      AppColors.transparent,
+    ]);
     final sectionTitle = tester.widget<Text>(find.text("This Week's Hits"));
     expect(sectionTitle.style?.fontSize, AppDimens.recommendSectionTitle);
     expect(sectionTitle.style?.fontWeight, FontWeight.w700);