fix(flutter): 放大播放图标并加半透明底

lib/pages/player/widgets/player_center_toggle.dart

@@ -4,8 +4,9 @@ import 'package:flutter/material.dart';
 
 import '../../../core/theme/app_colors.dart';
 
-const double _toggleSize = 72;
+const double _toggleSize = 84;
-const double _iconSize = 40;
+const double _iconSize = 48;
+const Color _toggleBackground = Colors.black26;
 const List<Shadow> _iconShadows = [
   Shadow(color: Colors.black54, blurRadius: 12),
 ];
@@ -28,9 +29,13 @@ class PlayerCenterToggle extends StatelessWidget {
       label: playing ? 'Pause' : 'Play',
       child: GestureDetector(
         onTap: onTap,
-        child: SizedBox(
+        child: Container(
           width: _toggleSize,
           height: _toggleSize,
+          decoration: const BoxDecoration(
+            color: _toggleBackground,
+            shape: BoxShape.circle,
+          ),
           child: Icon(
             playing ? Icons.pause_rounded : Icons.play_arrow_rounded,
             color: AppColors.onPrimary,

test/player/player_center_toggle_test.dart

@@ -6,7 +6,7 @@ import 'package:fruitshorts/core/theme/app_colors.dart';
 import 'package:fruitshorts/pages/player/widgets/player_center_toggle.dart';
 
 void main() {
-  testWidgets('should_use_one_shared_72px_transparent_toggle_style', (
+  testWidgets('should_use_one_shared_84px_translucent_toggle_style', (
     tester,
   ) async {
     await tester.pumpWidget(
@@ -34,16 +34,18 @@ void main() {
       Key('test-center-toggle-a'),
       Key('player-play-toggle'),
     ]) {
-      expect(tester.getSize(find.byKey(key)), const Size(72, 72));
+      expect(tester.getSize(find.byKey(key)), const Size(84, 84));
-      // 暂停按钮改为透明背景，容器已不再绘制任何底色或装饰。
+      // 圆形底改为半透明黑色，不再是完全透明或蓝色实底。
-      expect(
+      final container = tester.widget<Container>(
         find.descendant(of: find.byKey(key), matching: find.byType(Container)),
-        findsNothing,
       );
+      final decoration = container.decoration! as BoxDecoration;
+      expect(decoration.color, Colors.black26);
+      expect(decoration.shape, BoxShape.circle);
       final icon = tester.widget<Icon>(
         find.descendant(of: find.byKey(key), matching: find.byType(Icon)),
       );
-      expect(icon.size, 40);
+      expect(icon.size, 48);
       expect(icon.color, AppColors.onPrimary);
       expect(icon.shadows, isNotNull);
       expect(icon.shadows, isNotEmpty);