That looks pretty good. I also have a homegrown solution that does something similar but uses a css-like syntax but isn't like css. It's sufficient for my purpo

That looks pretty good. I also have a homegrown solution that does something similar but uses a css-like syntax but isn't like css. It's sufficient for my purposes though lacks many of the things your solution has. I'll have a more detailed look at CSSApply, and see if I can add to it :)