v4 breaking changes compared to v3

There have been several updates in TailwindCSS v4.

The installation process has changed:

• Upgrade guide - TailwindCSS v3 to v4

Some older features have been deprecated:

• Changed npx tailwindcss to npx @tailwindcss/cli - TailwindCSS v4 Docs
• Removed npx tailwindcss init process - StackOverflow
• Use @config directive to legacy JavaScript-config - StackOverflow

A CSS-first configuration has been implemented:

• CSS-first configuration instead of tailwind.config.js - TailwindCSS v4 Docs

Changed TailwindCSS v3 installation steps

npm i tailwindcss installs v4 by default. To install v3, use:

npm install -D tailwindcss@3

• TailwindCSS v3 installation guide with Vite

Answers based on the above information

Why aren't the tailwind.config.js and postcss.config.js files being generated automatically when running the installation commands?

The init process has been removed. There is no longer a need for tailwind.config.js, so nothing is automatically created anymore. However, you can still make it available using the @config directive and create it manually.

How can I resolve the error npm ERR! could not determine executable to run when initializing Tailwind CSS or Shadcn UI?

This error typically occurs when there is an issue with the command being run, such as a missing or incorrect executable. From the context, I infer that you're trying to run the init process, but as I mentioned, it has been deprecated.

Is there a specific configuration or prerequisite I might be missing for setting up Shadcn UI in a React.js (Vite + JavaScript) project?

• schadcn/app-tailwind-v4
• shadcn/ui #2996