PostCSS Error in Fresh Tailwind CSS v4 + Vite + ShadCN Project

[tanay-nagde]

I set up a fresh project using Tailwind CSS v4 with Vite and ShadCN. Initially, I used @tailwindcss/vite as a Vite plugin instead of PostCSS. Everything worked fine yesterday, but now I’m getting a PostCSS error, despite not having a postcss.config.js file in my project.

Here’s what I have tried so far:

• Reinstalled tailwindcss, @tailwindcss/vite, and vite.
• Removed node_modules, cleared cache, and reinstalled dependencies.
• Verified that PostCSS is only installed as a dependency of Vite ([email protected] -> [email protected]).
• Checked my vite.config.ts (removed and re-added @tailwindcss/vite).
• I also have tailwindcss-animate and tailwind-merge installed. My Tailwind styles file starts with:

@import "tailwindcss";
@plugin "tailwindcss-animate";

• Finally, I switched to using PostCSS instead of the Vite plugin, but why its not working by plugin method

Key Questions:

Does ShadCN require a specific PostCSS setup?
Why is this issue occurring in a fresh Tailwind CSS v4 project?
How can I resolve this error?

[MikeBellika]

What version of tailwind are you using, what error message are you getting, and does it work if you use 4.0.11? Having some issues similar issues with nuxt. Currently I'm getting this error:

[9:42:01 PM]  ERROR  Pre-transform error: Exceeded maximum recursion depth while resolving tailwindcss/utilities in /Users/mike/code/my_project/node_modules/.pnpm/[email protected]/node_modules/tailwindcss)
  Plugin: @tailwindcss/vite:generate:serve
  File: /Users/mike/code/my_project/app/hub/assets/css/main.css

However earlier i was getting errors relating to postcss.

[tanay-nagde]

my exact error message was

[vite] Internal server error: Failed to load PostCSS config (searchPath: D:/edtech/edtech-frontend): [Error] Loading PostCSS Plugin failed: Cannot find module 'tailwindcss' Require stack:

D:\postcss.config.mjs
(@D:\postcss.config.mjs) Error: Loading PostCSS Plugin failed: Cannot find module 'tailwindcss' Require stack:

D:\postcss.config.mjs

"tailwindcss": "^4.0.12",

[sunwrobert]

I'm also hitting this 😢 . Using a NextJS project

Seems to specifically break on 4.0.14. 4.0.13 and below works fine.