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/components/Footer.tsx

@@ -7,7 +7,7 @@ const Footer: React.FC = () => {
       whileInView={{ opacity: 1, y: 0 }}
       viewport={{ once: true, margin: '-50px' }}
       transition={{ duration: 0.5, ease: 'easeOut' }}
-      className="text-center pt-12 pb-8 border-t border-slate-200"
+      className="text-center pt-8 xs:pt-12 pb-6 xs:pb-8 border-t border-slate-200"
     >
       <svg
         className="block mx-auto mb-3"