Well, I wrote a functional CSS framework that is platform agnostic. It was built on sass. Post: https://www.minid.net/2019/4/7/the-css-utilitarian-methodolo..., github https://github.com/meerita/utilcss I am working a different project now, and now I evolved it to simply pure css files that i compile later with postcss and purge everything.

The latest and newest i did https://github.com/meerita/fcss

just drop into your react app, in this order:

root.css normalizer.css generics.css (all css classes) sm.css (mobile classes) md.css (mid desktop/iPad) lg.css (standard desktop) xl.css (large desktop) xxl for large large desktops

The usage is easy, lets build a grid:

<div className='display--grid gap--8'>...</div>

Those are from the generics.css, but if you need 2 cols in mobile and 4 in desktop you can do it

<div className='display--grid gap--8 sm-template-columns--2 md-template-columns--4'>...</div>

The structure of every class is made using the css language, contrary to tailwind has its own syntax. it takes huge amount of time and mental effort to get it. With FCSS you learn the pattern and you can advance it or extend it.