Fix Tailwind CSS v4 migration

- Update globals.css to use @import "tailwindcss" and @config
- Remove incompatible plugins (tailwindcss-animate, @tailwindcss/forms)
- Add @tailwindcss/postcss for v4 compatibility

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -41,12 +41,10 @@
     "react-ga4": "^2.1.0",
     "react-intersection-observer": "^10.0.2",
     "tailwind-merge": "^3.4.0",
-    "tailwindcss-animate": "^1.0.7",
     "web-vitals": "^5.1.0"
   },
   "devDependencies": {
     "@playwright/test": "^1.58.1",
-    "@tailwindcss/forms": "^0.5.11",
     "@tailwindcss/postcss": "^4.1.18",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.2",
@@ -63,7 +61,6 @@
     "playwright-lighthouse": "^4.0.0",
     "postcss": "^8.5.6",
     "sharp": "^0.34.5",
-    "tailwindcss": "^4.1.18",
     "typescript": "^5.9.3",
     "vitest": "^4.0.18"
   }