Fix Tailwind CSS v4 configuration

- Update src/index.css to use @import "tailwindcss" (v4 syntax)
- Remove tailwind.config.js (not needed in v4)
- Tailwind styles now properly applied

src/index.css

@@ -1,3 +1 @@
-@tailwind base;
-@tailwind components;
-@tailwind utilities;
+@import "tailwindcss";

tailwind.config.js

@@ -1,11 +0,0 @@
-/** @type {import('tailwindcss').Config} */
-export default {
-  content: [
-    "./index.html",
-    "./src/**/*.{js,ts,jsx,tsx}",
-  ],
-  theme: {
-    extend: {},
-  },
-  plugins: [],
-}