Tailwind CSS Impl: v3 Configuration (tailwind.config.js)

In v3.4 the entire Tailwind project is configured through a single JavaScript file (tailwind.config.js / .mjs / .ts). Every behaviour, every token, every plugin lives here. Mastering this file is mastering v3. NOTE: v4 moves most of this into CSS @theme { ... } blocks ; this skill is v3-ONLY and explicitly flags every option that is REMOVED in v4.

Quick Reference

Option matrix (v3.4 full surface)