The installation of TailwindCSS v3 and v4 is different. You were expecting the v3 installation, but v4 is the new latest version. For v3 installation, use:

npm install -D tailwindcss@3

• Cannot build frontend with TailwindCSS - StackOverflow

However, if you want to install v4, I recommend reviewing the installation guides, as there are significant breaking changes between v3 and v4.

npm install tailwindcss @tailwindcss/vite

• Get started with Tailwind CSS - TailwindCSS v4 Docs
• Upgrading your Tailwind CSS projects from v3 to v4 - TailwindCSS v4 Docs
• Removed @tailwind directives
• Deprecated: Sass, Less and Stylus preprocessors support
• Deprecated init process