fix: update styles for dark mode support

components/footer.tsx

@@ -1,6 +1,6 @@
 export default function Footer() {
   return (
-    <footer className="w-full bg-white shadow p-4 text-left text-gray-500 flex flex-row gap-2">
+    <footer className="w-full bg-white dark:bg-gray-950 shadow p-4 text-left text-gray-500 dark:text-gray-400 flex flex-row gap-2">
       <div className="container mx-auto">
         <div>© {new Date().getFullYear()} 智能计算实验室 · Designed by LufsX.</div>
       </div>

components/header.tsx

@@ -2,18 +2,18 @@ import Link from "next/link";
 
 export default function Header() {
   return (
-    <header className="home-header px-4 w-full bg-white shadow flex sm:px-8">
+    <header className="home-header px-4 w-full bg-white dark:bg-gray-950 shadow flex sm:px-8">
       <nav className="container mx-auto flex justify-between items-center">
         <div className="flex items-center">
           <Link href="/">
-            <h1 className="text-2xl font-bold text-gray-900">智能计算实验室</h1>
+            <h1 className="text-2xl font-bold text-gray-900 dark:text-gray-100">智能计算实验室</h1>
           </Link>
         </div>
         <div className="flex space-x-4">
-          <Link className="nav-link py-3 px-2" href="/">
+          <Link className="nav-link py-3 px-2 text-gray-700 dark:text-gray-200 hover:text-blue-600 dark:hover:text-blue-400 transition-colors" href="/">
             首页
           </Link>
-          {/* <Link className="nav-link py-3 px-2" href="/contacts">
+          {/* <Link className="nav-link py-3 px-2 text-gray-700 dark:text-gray-200 hover:text-blue-600 dark:hover:text-blue-400 transition-colors" href="/">
             联系
           </Link> */}
         </div>