This is makes little sense. According to this I’m an expert but not advanced.

CSS architecture (for a lack of a better term) is completely different from its more playful aspects. Stacking on on top of the other is just silly.

The "expert" description is far too vague and easily interpreted as less advanced than the "advanced" category. Results for this question are meaningless.

Exactly my reaction. I do think that you can create stunning animations and for that you need some expertise but animations are the "the basis" for a complete and successful front-end.

You're absolutely right. I'd bet the CSS experts understand the context of the question and the difficulty involved in "styling an entire front-end app from scratch with consistency." I think a lot of novices looked at that and thought it meant using one of the css grid / framework libraries and making a website. The question hides how difficult that actually is with CSS and how easy it seems if you've never had to do it.