Error when use new version 4.x.x

[baohg1108]

Hi programmers, I am a freshman practicing FE. After reading the manual and following it, I encountered a very annoying error. I have consulted Stack overflow as well as other documents but cannot fix it. Please help me. Thanks. ERROR: Error: It looks like you're trying to use tailwindcss directly as a PostCSS plugin. The PostCSS plugin has moved to a separate package, so to continue using Tailwind CSS with PostCSS you'll need to install @tailwindcss/postcss and update your PostCSS configuration.

[wongjn]

It looks like you're trying to use tailwindcss directly as a PostCSS plugin. The PostCSS plugin has moved to a separate package, so to continue using Tailwind CSS with PostCSS you'll need to install @tailwindcss/postcss and update your PostCSS configuration:

 export default {
   plugins: {
-    "tailwindcss: {},
+    "@tailwindcss/postcss": {},
   }
 }

[KaloudasDev]

Hello! Welcome to frontend development! This error occurs because Tailwind CSS v4 moved the PostCSS plugin to a separate package. Here's the complete fix:

Step 1: Install the New Package

npm install -D @tailwindcss/postcss

Step 2: Update Your PostCSS Configuration

// postcss.config.js
export default {
  plugins: {
    '@tailwindcss/postcss': {},
    autoprefixer: {},
  }
}

Step 3: Verify Your Tailwind CSS Setup
Ensure your main CSS file uses the correct imports:

/* app.css or main.css */
@import "tailwindcss";

If You're Using Older Configuration Syntax:

// For CommonJS syntax (postcss.config.cjs)
module.exports = {
  plugins: {
    '@tailwindcss/postcss': {},
    autoprefixer: {},
  }
}

Additional Check for Build Tools:
If you're using Vite, Next.js, or other frameworks, ensure your configuration matches:

// vite.config.js (if using Vite)
export default {
  css: {
    postcss: './postcss.config.js'
  }
}

This change was made in Tailwind CSS v4 to separate concerns and improve maintainability. The functionality remains the same - you're just using the dedicated PostCSS plugin package now.