refactor(ui): [UI8] 补齐全局异常卡片边距并统一剩余下拉表单样式

client/src/pages/NotFoundPage.tsx

@@ -3,7 +3,7 @@ import { Link } from "react-router-dom";
 export function NotFoundPage() {
   return (
     <div className="flex min-h-screen items-center justify-center bg-background-light p-6">
-      <div className="card-std max-w-lg text-center">
+      <div className="card-std p-8 max-w-lg text-center">
         <p className="text-sm font-semibold uppercase tracking-wide text-primary">404</p>
         <h1 className="mt-2 text-2xl font-bold text-zinc-900">页面不存在</h1>
         <p className="mt-2 text-sm text-secondary">请检查地址，或返回工作台首页继续操作。</p>