[wwweston]

Those are certainly everyday concerns for people doing UI work, but I'm not sure I see how they're specific criticisms of CSS.

Global is going to mean global, regardless of whatever's managing the appearance, and the only UI systems I can imagine that wouldn't have a problem like this would be those with an entirely uncustomizable global UI presentation.

And for differing stylings inside a specific visual component -- generally, specificity is on your side here, most of the time the selectors involved in component-specific rules will naturally override global styles and you'd only fighting specificity if there's another component specific rule. If that's the case, though, what system would save you from conflicting rules applied to a specific component?