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

tailwind.config.js

@@ -5,6 +5,13 @@ export default {
     "./src/**/*.{js,ts,jsx,tsx}",
   ],
   theme: {
+    screens: {
+      'xs': '480px',
+      'sm': '640px',
+      'md': '768px',
+      'lg': '1024px',
+      'xl': '1280px',
+    },
     extend: {
       colors: {
         teal: {