Personally? Not a fan. Wish it would have stuck to utility classes.
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.
Having said that we switched to Tailwind for a very specific reason: customisability. see: https://github.com/dwyl/learn-tailwind#what-about-tachyons
Still Tachyons is a perfectly valid and lightweight utility class based CSS library.