restrict feed width in desktop

src/pages/AuthorPage.tsx

@@ -16,8 +16,10 @@ export function AuthorPage() {
   const posts = useAsyncState(fetchPosts)
 
   return (
-    <main className={`w-full max-w-full`}>
-      <PostsFeed posts={posts ?? []} />
+    <main className={`w-full max-w-full md:flex md:justify-center`}>
+      <div className="w-full md:w-lg md:max-w-lg md:ml-8">
+        <PostsFeed posts={posts ?? []} />
+      </div>
     </main>
   )
 }