1. The one feature I prefer in Marko when compared to Mint is Marko’s nice ID and class syntax, rather than your custom selectors, so you can just use regular CSS (which seems to be advancing faster than the JS & HTML specs combined). You could get the scoping using shadow roots for your components (I’m sure this has flow on consequences, but given you own the language it’s probably better case than many others.)
2. Interpolating values directly in CSS blocks is something that a lot of HTML templating systems sort of give up on (see Astro going out of it’s way to make interpolating variables super verbose [0]), so I’m glad to see you do it. Does the value interpolation compile to CSS variables that are set on the component root (or somewhere else I suppose) as in Astro [0], or is it just simple interpolation? Additionally, I can’t help but notice your hash symbol would conflict with ID selectors, so is CSS nesting available?
Please don’t take this as criticism! I really like what you’ve done here and am very curious.
[0]: https://docs.astro.build/en/guides/styling/#css-variables