重构布局组件，优化导航栏和头部结构；调整样式以改善响应式设计

src/app/admin/_client/header.tsx

@@ -13,21 +13,21 @@ export default function Header(props: HeaderProps) {
 
   return (
     <header className={merge(
-      `flex-none h-16`,
+      `flex-none h-16 overflow-hidden`,
       `flex items-stretch`,
     )}>
       {/* left */}
       <div className="flex-auto flex items-center gap-2">
         <Button
           theme="ghost"
-          className="w-9 h-9"
+          className="w-9 h-9 ml-4 md:ml-0"
           onClick={toggleNavbar}>
           {navbar
             ? <PanelLeftCloseIcon/>
             : <PanelLeftOpenIcon/>
           }
         </Button>
-        <span>
+        <span className="max-md:hidden">
           欢迎来到，蓝狐代理
         </span>
       </div>