Interesting, so if I'm understanding correctly, component A's style was supposed to change when component B was present, and this was implemented as styling rules in component B? Why was Tailwind necessary rather than moving these rules to component A (which I know would probably require some gnarly selectors)?

I don't want to be a "you should've double bagged it" guy, I'm just curious. Svelte is not the be all and all, if you moved on to greener pastures more power to you.