Pretty much what I expect from Svelte, and sadly that's not a good thing. ALSO what I expect from Github in making it as hard as humanly possible to find a damned thing thanks to the dozens of pointless files crapped all over the place across endless pointless directories... ALSO not a fan.

I'm not 100% familiar with svelte apart from ripping it out of two different projects where in both cases it was doing more harm than good... just like every other halfwit bloated train wreck of derpitude "framework" IDIOCY.

My biggest concern with your implementation is the lack of scripting off graceful degradation. The fact that the button to show/hide is there whether the client-side scripting is working fails the graceful degradation requirement common to accessibility norms. You end up with a button that does nothing, confusing the user on things like screen readers, braille readers, etc. That's why I added it from the scripting on the DOM. It's also why you don't s*** on your markup with onevent attributes.

Because of how svelte slops together what you've written, it also would crap the style and scripting into the markup pissing on caching models.

Though I could be mistaken on that since you didn't provide a live working copy, and I lack the time to set up a BS testing server just for some garbage back-end system (svelte) that I'd likely NEVER use in the first blasted place. Why? Same reason I think React, Vue, Angular, bootcrap, tailwind, etc, etc, etc, are all inept ignorant incompetent trash made by people not qualified to write a single blasted line of HTML or CSS.

But let me tell you what I really think. Just from what I've seen on your example ALONE, I'd sooner eat a bullet than use svelte for something like this.