feat(leetcode_card): 优化界面展示效果并添加刷新动画

- 增加 AnimationController 以实现刷新动画效果
- 调整文本样式和大小，提升可读性
- 在用户击败百分比和最近提交部分增加加粗显示
- 优化提交记录为空时的显示效果
- 在刷新按钮周围添加旋转动画

lib/widgets/leetcode_card.dart

@@ -12,7 +12,10 @@ class LeetCodeCard extends StatefulWidget {
   State<LeetCodeCard> createState() => _LeetCodeCardState();
 }
 
-class _LeetCodeCardState extends State<LeetCodeCard> {
+class _LeetCodeCardState extends State<LeetCodeCard>
+    with SingleTickerProviderStateMixin {
+  late AnimationController _refreshController;
+
   List<dynamic> _submissions = [];
   Map<String, dynamic>? _progress;
   bool _isLoading = false;
@@ -118,6 +121,10 @@ class _LeetCodeCardState extends State<LeetCodeCard> {
   void initState() {
     super.initState();
     _fetchData();
+    _refreshController = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 500),
+    );
   }
 
   Widget _buildProgressCard() {
@@ -135,7 +142,7 @@ class _LeetCodeCardState extends State<LeetCodeCard> {
           children: [
             const Text(
               '解题进度',
-              style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
+              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
             ),
             const SizedBox(height: 8),
             ...acceptedQuestions.map((q) {
@@ -153,8 +160,13 @@ class _LeetCodeCardState extends State<LeetCodeCard> {
             Row(
               mainAxisAlignment: MainAxisAlignment.spaceBetween,
               children: [
-                const Text('击败用户'),
-                Text('${totalBeatsPercentage.toStringAsFixed(1)}%'),
+                const Text('击败用户',
+                    style: TextStyle(fontWeight: FontWeight.bold)),
+                Text('${totalBeatsPercentage.toStringAsFixed(1)}%',
+                    style: const TextStyle(
+                        fontWeight: FontWeight.bold,
+                        fontSize: 16,
+                        color: Colors.green)),
               ],
             ),
           ],
@@ -176,19 +188,34 @@ class _LeetCodeCardState extends State<LeetCodeCard> {
               children: [
                 const Text(
                   'LeetCode 最近提交',
-                  style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
+                  style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
                 ),
-                IconButton(
-                  icon: const Icon(Icons.refresh),
-                  onPressed: _isLoading ? null : _fetchData,
+                RotationTransition(
+                  turns: _refreshController,
+                  child: IconButton(
+                    icon: const Icon(Icons.refresh, size: 28),
+                    onPressed: _isLoading
+                        ? null
+                        : () async {
+                            _refreshController.forward(from: 0.0);
+                            await _fetchData();
+                          },
+                  ),
                 ),
               ],
             ),
             if (_isLoading)
-              const Center(
+              Center(
                 child: Padding(
-                  padding: EdgeInsets.all(16.0),
-                  child: CircularProgressIndicator(),
+                  padding: const EdgeInsets.all(16.0),
+                  child: AnimatedBuilder(
+                    animation: _refreshController,
+                    builder: (_, child) => Transform.rotate(
+                      angle: _refreshController.value * 2 * 3.14,
+                      child: child,
+                    ),
+                    child: const CircularProgressIndicator(),
+                  ),
                 ),
               )
             else if (_error != null)
@@ -212,7 +239,8 @@ class _LeetCodeCardState extends State<LeetCodeCard> {
                         const Center(
                           child: Padding(
                             padding: EdgeInsets.all(16.0),
-                            child: Text('暂无提交记录'),
+                            child:
+                                Text('暂无提交记录', style: TextStyle(fontSize: 16)),
                           ),
                         )
                       else
@@ -228,12 +256,16 @@ class _LeetCodeCardState extends State<LeetCodeCard> {
                               title: Text(
                                 question['translatedTitle'] ??
                                     question['title'],
+                                style: const TextStyle(fontSize: 16),
                               ),
                               subtitle: Text(
                                 '提交时间: ${timeago.format(DateTime.fromMillisecondsSinceEpoch(submission['submitTime'] * 1000), locale: 'zh_CN')}',
+                                style: const TextStyle(fontSize: 14),
                               ),
                               trailing: Text(
                                 '#${question['questionFrontendId']}',
+                                style: const TextStyle(
+                                    fontSize: 14, fontWeight: FontWeight.bold),
                               ),
                             );
                           },