tailwind css problem

package.json

@@ -24,16 +24,21 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.25.0",
+    "@tailwindcss/postcss": "^4.1.10",
+    "@tailwindcss/vite": "^4.1.10",
     "@types/react": "^19.1.8",
     "@types/react-dom": "^19.1.2",
     "@vitejs/plugin-react": "^4.4.1",
+    "autoprefixer": "^10.4.21",
     "eslint": "^9.25.0",
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.19",
     "globals": "^16.0.0",
     "husky": "^9.1.7",
     "lint-staged": "^16.1.2",
+    "postcss": "^8.5.6",
     "prettier": "^3.5.3",
+    "tailwindcss": "^4.1.10",
     "typescript": "~5.8.3",
     "typescript-eslint": "^8.30.1",
     "vite": "^6.3.5"

postcss.config.cjs

@@ -0,0 +1,6 @@
+module.exports = {
+  plugins: {
+    '@tailwindcss/postcss': {},
+    autoprefixer: {},
+  }
+}

src/Components/Header.tsx

@@ -1,7 +1,9 @@
 export const Header = () => {
     return (
-        <header className="bg-gray-800 text-white p-4">
+        <header className="!bg-blue-500 text-white p-4 border border-black">
             <h1 className="text-xl">StoreZero</h1>
+            {/* Debug element */}
+            <div className="w-full h-8 bg-red-500 mt-2 border border-black"></div>
         </header>
     )
 }

src/index.css

@@ -0,0 +1 @@
+@import "tailwindcss";

src/main.tsx

@@ -1,6 +1,6 @@
+import './index.css'
 import { StrictMode } from 'react'
 import { createRoot } from 'react-dom/client'
-import './index.css'
 import App from './App.tsx'
 
 createRoot(document.getElementById('root')!).render(

tailwind.config.cjs

@@ -0,0 +1,16 @@
+module.exports = {
+  content: [
+    "./index.html",
+    "./src/**/*.{js,ts,jsx,tsx}",
+  ],
+  theme: {
+    extend: {
+      colors: {
+        red: {
+          500: '#ef4444', // Explicitly define red-500
+        }
+      }
+    },
+  },
+  plugins: [],
+}

vite.config.ts

@@ -1,7 +1,8 @@
 import { defineConfig } from 'vite'
 import react from '@vitejs/plugin-react'
+import tailwindcss from '@tailwindcss/vite'
 
 // https://vite.dev/config/
 export default defineConfig({
-    plugins: [react()],
+    plugins: [react(), tailwindcss()],
 })