feat: 添加预览效果页面并优化交互效果

refactor: 优化代码健壮性和类型安全

style: 更新字体样式和全局CSS

fix: 修复IntersectionObserver潜在空引用问题

chore: 更新依赖和ESLint配置

build: 更新构建ID和路由配置

src/app/(marketing)/contact/page.tsx

@@ -13,10 +13,9 @@ export default function ContactPage() {
   const [isSubmitting, setIsSubmitting] = useState(false);
   const [isSubmitted, setIsSubmitted] = useState(false);
 
-  async function handleSubmit(formData: FormData) {
+  async function handleSubmit(_formData: FormData) {
     setIsSubmitting(true);
     
-    // Simulate form submission
     await new Promise(resolve => setTimeout(resolve, 1500));
     
     setIsSubmitting(false);