backend opti

frontend/src/pages/posts/[slug].astro

@@ -71,6 +71,11 @@ const displayTitle = post ? (post.title || formatSlug(post.slug)) : 'Work';
     image={post?.cover_image?.url}
     type="article"
 >
+  {post?.cover_image?.url && (
+    <Fragment slot="head">
+      <link rel="preload" as="image" href={post.cover_image.url} fetchpriority="high" />
+    </Fragment>
+  )}
   <div id="reading-progress" class="reading-progress" aria-hidden="true"></div>
 
   {error && (
@@ -192,9 +197,18 @@ const displayTitle = post ? (post.title || formatSlug(post.slug)) : 'Work';
         const pct = Math.max(0, Math.min(1, (window.scrollY - startY) / distance));
         bar.style.transform = 'scaleX(' + pct + ')';
       }
+      let pending = false;
+      function schedule() {
+        if (pending) return;
+        pending = true;
+        requestAnimationFrame(function () {
+          pending = false;
+          update();
+        });
+      }
       update();
-      window.addEventListener('scroll', update, { passive: true });
-      window.addEventListener('resize', update);
+      window.addEventListener('scroll', schedule, { passive: true });
+      window.addEventListener('resize', schedule);
     })();
   </script>
 </Layout>