Add fluid typography scale and responsive headings

app/blog/page.tsx

@@ -11,10 +11,10 @@ export default function BlogIndexPage() {
   return (
     <section className="space-y-4">
       <header className="space-y-1">
-        <h1 className="text-lg font-semibold text-slate-900 dark:text-slate-50">
+        <h1 className="type-title font-semibold text-slate-900 dark:text-slate-50">
           所有文章
         </h1>
-        <p className="text-xs text-slate-500 dark:text-slate-400">
+        <p className="type-small text-slate-500 dark:text-slate-400">
           繼續往下滑，慢慢逛逛。
         </p>
       </header>