Headline: Tailwind v4 is the most significant rewrite since the framework launched — CSS-first config, Lightning CSS under the hood, container queries built-in, and no more tailwind. config. js .
Source: [Dev.to](https://dev.to/ahmed_mahmoud360/tailwind-css-v4-what-actually-changed-and-how-i-migrated-two-projects-2f7b)