Post #2392941

@leaverou@front-end.social That's maybe still not super-intuitive, but it's consistent with established patterns about how custom properties work. It would probably be easily integrated with existing Dev Tools error messages to help people figure out what's going on. And I like that it doesn't invalidate any declarations that *don't* depend on the input argument. Although, it would still break some Sass-style mixins that are just trying to pass in an uncomputed token & use it to generate a set of related rules.