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/bills/page.tsx

@@ -96,10 +96,9 @@ export default function BillsPage(props: BillsPageProps) {
       {/* 操作区 */}
       <section className="flex justify-between flex-wrap">
         <div>
-          <h1 className="text-xl font-bold">账单管理</h1>
         </div>
 
-        <Form form={form} onSubmit={onSubmit} className="flex items-end gap-4">
+        <Form form={form} onSubmit={onSubmit} className="flex items-end gap-4 flex-wrap">
           <FormField name="type" label={<span className="text-sm">账单类型</span>}>
             {({id, field}) => (
               <Select value={field.value} onValueChange={field.onChange}>