The timing is interesting. Stylex (Metas CSS in JS library) is taking off right now because it seems a better fit for AI driven coding in the long run.
Apparently they did a long experiment with Stylex at Shopify and found that it was "a wash in every metric":
And it has an explicit LLM Resources endpoint: https://stylexjs.com/docs/llm-resources
Linear adopted stylex as well and published a comprehensive write up https://linear.app/now/styling-linear-for-the-future-stylex