Task 11: Implement scroll animations and responsive design

- Add xs (480px) breakpoint to tailwind config for mobile
- Standardize scroll-reveal animations to opacity 0→1, y 24→0
- Add responsive padding to main container (px-5 xs:px-6 md:px-8)
- Add responsive section padding (py-12 xs:py-16 md:py-20)
- FloatingNav: responsive width and font/padding on mobile
- Hero: responsive vitals grid, title font clamp to 28px min
- Skills: responsive grid (2→3→auto-fit), smaller gauges on mobile
- Experience: responsive card padding, ECG decoration size
- Education/Projects: responsive grids matching concept.html
- Contact/Footer: responsive padding

src/App.tsx

@@ -27,7 +27,7 @@ function App() {
       {phase === 'content' && (
         <>
           <FloatingNav />
-          <main className="max-w-[1000px] mx-auto px-8">
+          <main className="max-w-[1000px] mx-auto px-5 xs:px-6 md:px-8">
             <Hero />
             
             <Skills />