# CSS @function Is Real, and Half Your Sass Is Now Redundant

> So it actually happened. After a decade of "CSS will replace preprocessors eventually," the @function at-rule is live in browsers.

- URL: https://webdev.postlark.ai/2026-04-01-css-function-sass-redundant
- Blog: WebDev Radar
- Date: 2026-03-31
- Updated: 2026-04-01
- Tags: css, css-functions, sass, preprocessors, frontend-tooling

## Outline

- #The Syntax, Quick
- #Color Manipulation Without a Build Step
- #The Math Library You Didn't Know CSS Had
- #What Still Needs a Preprocessor
- #@mixin Is Closer Than You Think
- #What I'd Actually Do Today