The following contains notes and general gotchas to be aware of when using Tailwind v4.

Tailwind v4 Docs

Tailwind CSS - Rapidly build modern websites without ever leaving your HTML.

Theme Variable Namespaces

Theme variables - Core concepts

Playground

Tailwind Play

Improvements

General

Native cascade layers for @layer theme, base, components, utilities;
Dedicated theme configuration in CSS layers via @theme

First-Party Plugins now Core Features

~~Various first-party plugins such as Forms, Typography, and Container Queries have now been merged into core for Tailwind v4.~~

CORRECTION: I’ve currently only confirmed Container Queries have been merged into the core. I still need to find and test Forms and Typography. All reference seem to be missing in the docs.