> So basically you're abusing the fact that (modern) browsers treat unknown tags more or less as divs and built a small CSS framework with these names.

The spec allows custom elements[0] and pretty much requires this behaviour.

> you're breaking all HTML semantics and your markup is not accessible.

Calling the markup non-accessible is defensible[1], but it doesn't break HTML semantics in any way.

[0] https://html.spec.whatwg.org/multipage/custom-elements.html#...

[1] though it wouldn't be more accessible as a stack of divs and the custom element can be aria-tagged[2], in the browsers supporting it it's also possible to use customised elements but here there's little of interest

[2] https://html.spec.whatwg.org/multipage/custom-elements.html#...

Custom element names must contain a hyphen for forwards-compatibility, and these do not.

https://html.spec.whatwg.org/multipage/custom-elements.html#...

The Custom Elements spec requires all custom elements to have a hyphenated name.

Came to say the same thing. Seems odd to me, personally. Why not just make them class names, and you could probably still get an even smaller sized framework (if that was the main goal)?

I think the idea is to also abstract away the choice of elements in favor of familiar container names. Make it only class names and you're back to a simple CSS framework like tons of others already.

This could work with a build system or as a templating engine. The names and logic is sound, but as you said it makes little senses to use those tags as-is in production.