fix: prevent content flash before GSAP intro animations

- Hide header-reveal, hero-line, hero-title words, hero-text and
  hero-actions via CSS visibility:hidden before JS runs
- Restore visibility:visible in gsap.set() calls so GSAP owns the
  full lifecycle with no flash of unstyled content

Author: dacrab

src/components/Header.astro

@@ -86,7 +86,7 @@ const links = [
   const bottomBar = document.getElementById('bar-bottom')!;
   let isMenuOpen = false;
 
-  gsap.set('.header-reveal', { y: -40, opacity: 0 });
+  gsap.set('.header-reveal', { y: -40, opacity: 0, visibility: 'visible' });
   gsap.set('.menu-item', { y: 20, opacity: 0 });
   gsap.to('.header-reveal', {
     y: 0,

src/components/Hero.astro

@@ -41,9 +41,9 @@
   import gsap from 'gsap';
   import { addHoverAnimation, DURATION, EASE, isMobile } from '../utils/animations';
 
-  gsap.set('.hero-line', { scaleY: 0 });
-  gsap.set('.hero-title .word', { y: '100%', opacity: 0 });
-  gsap.set(['.hero-text', '.hero-actions'], { opacity: 0, y: 32 });
+  gsap.set('.hero-line', { scaleY: 0, visibility: 'visible' });
+  gsap.set('.hero-title .word', { y: '100%', opacity: 0, visibility: 'visible' });
+  gsap.set(['.hero-text', '.hero-actions'], { opacity: 0, y: 32, visibility: 'visible' });
 
   if (isMobile) {
     gsap.timeline()

src/styles/global.css

@@ -15,4 +15,13 @@
       linear-gradient(to bottom, rgba(0, 0, 0, 0.04) 1px, transparent 1px);
     background-size: 4rem 4rem;
   }
+
+  /* Hide elements that GSAP animates in on load — prevents flash before JS runs */
+  .header-reveal,
+  .hero-line,
+  .hero-title .word,
+  .hero-text,
+  .hero-actions {
+    visibility: hidden;
+  }
 }