I use Pico with LLM code gen for new projects. As you probably know, LLMs are predisposed to Tailwind and coding for industrial strength on any tiniest projects. The trick is to feed it the whole Pico docs as context and prompt it (i.e. in your CLAUDE.md) to use Pico explicitly.
Did you do anything fancy to get the whole Pico docs into context? I see on their website that their docs are split up across a bunch of pages, did you copy+paste each one into a large prompt document? I was hoping to see a single-page docs download but I didn't find one.