fix: show nav bar earlier

src/components/Header.astro

@@ -136,6 +136,8 @@ const { version } = Astro.props;
     if (!header || !hero) return;
 
     // Show/hide header based on scroll past hero
+    // Show header when top half of hero is above the fold
+    const topMargin = Math.floor(window.innerHeight / 2);
     const observer = new IntersectionObserver(
       ([entry]) => {
         if (entry.isIntersecting) {
@@ -148,7 +150,7 @@ const { version } = Astro.props;
           header.classList.add("dark:border-[var(--color-dark-border)]");
         }
       },
-      { threshold: 0, rootMargin: "-64px 0px 0px 0px" }
+      { threshold: 0, rootMargin: `-${topMargin}px 0px 0px 0px` }
     );
 
     observer.observe(hero);