Install Tailwind v4

Install Tailwind CSS v4 with Next.js

npx create-next-app@latest my-project --typescript --eslint --app
cd my-project

Install @tailwindcss/postcss and its peer dependencies.

npm install tailwindcss @tailwindcss/postcss postcss

postcss.config.mjs

const config = {
  plugins: {
    "@tailwindcss/postcss": {},
  },
};
export default config;

globals.css

@import "tailwindcss";

npm run dev

page.tsx

export default function Home() {
  return (
    <h1 className="text-3xl font-bold underline">
      Hello world!
    </h1>
  )
}

Eunary