fix: 恢复对话页面头部样式 - 紫色渐变背景 + 搜索按钮 + 新建对话按钮

www/style.css

@@ -108,29 +108,56 @@ body {
   height: 100%;
 }
 
+.chats-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 12px 16px;
+  background: linear-gradient(135deg, var(--primary) 0%, #764ba2 100%);
+  color: white;
+}
+
+.chats-header h1 {
+  font-size: 18px;
+  font-weight: 600;
+}
+
+.chats-header-actions {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.chats-header-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 44px;
+  height: 44px;
+  background: rgba(255,255,255,0.95);
+  border: none;
+  border-radius: 50%;
+  color: var(--primary);
+  cursor: pointer;
+  transition: all 0.25s ease;
+  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
+}
+
+.chats-header-btn:hover {
+  transform: scale(1.08);
+  box-shadow: 0 4px 16px rgba(102,126,234,0.4);
+  color: #5a67d8;
+}
+
+.chats-header-btn:active {
+  transform: scale(0.95);
+}
+
 .chats-content {
   flex: 1;
   padding: 16px;
   overflow-y: auto;
-}
-
-.new-chat-btn {
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  width: 40px;
-  height: 40px;
-  background: var(--primary);
-  border: none;
-  border-radius: 10px;
-  color: white;
-  cursor: pointer;
-  transition: all 0.2s;
-}
-
-.new-chat-btn:hover {
-  background: #5a67d8;
-  transform: scale(1.05);
+  background: #f5f5f5;
 }
 
 /* ==================== 智能体页面 ==================== */