[austinjp]

Personally I'm a fan of cxs [0] which is (or purports to be) atomic among other strengths. From the readme:

  - 0.7 KB (gzipped)
  - Zero dependencies
  - High performance ("fast af")
  - Deduplicates repeated styles
  - Dead-code elimination
  - Media queries and pseudoclasses supported

Works with any framework or with none, apparently, although I've only used it with Preact. Supports themes. Everything I need and nothing I don't.

[0] https://github.com/cxs-css/cxs

[jitl]

I think csx is probably the best choice amongst the compute-styles-at-runtime CSS-in-JS libraries. The brutal simplicity has a lot to offer. For most projects csx is perfectly fine. However it can’t beat a more complex zero-runtime precompiled styles system on paper — but it’s an optimization tradeoff you could choose if you need it in the future.