style(game): 优化游戏界面样式和布局

- 调整玩家头像位置和旋转效果
- 将玩家卡片样式从全局CSS分离到房间页面独立控制
- 优化桌面背景墙布局参数
- 修复左右侧玩家头像图片旋转显示问题
- 统一游戏场景中元素定位和间距配置

src/assets/styles/global.css

@@ -799,27 +799,27 @@ button:disabled {
 }
 
 .player-badge.seat-top {
-  top: 28px;
+  top: 20px;
   left: 50%;
   transform: translateX(-50%);
 }
 
 .player-badge.seat-right {
-  right: 24px;
+  right: -20px;
   top: 50%;
-  transform: translateY(-50%);
+  transform: translateY(-50%) rotate(90deg);
 }
 
 .player-badge.seat-bottom {
-  bottom: 136px;
+  bottom: 20px;
   left: 50%;
   transform: translateX(-50%);
 }
 
 .player-badge.seat-left {
-  left: 24px;
+  left: -20px;
   top: 50%;
-  transform: translateY(-50%);
+  transform: translateY(-50%) rotate(90deg);
 }
 
 .player-badge.is-turn {
@@ -853,6 +853,14 @@ button:disabled {
   object-fit: cover;
 }
 
+.player-badge.seat-right .avatar-card img {
+  transform: rotate(-90deg);
+}
+
+.player-badge.seat-left .avatar-card img {
+  transform: rotate(-90deg);
+}
+
 .player-meta p {
   font-size: 14px;
   font-weight: 700;