www-style: the discussion is about the :root selector in the Selectors
specification.
> Yeah, it really should say "a document".
That doesn't solve the problem, in some ways, since it might mean that multiple
nodes being rendered in the same window match :root, depending on what
transclusion technologies people come up with. Perhaps that's desirable.
What would make the most sense to me, I guess, would be to have it that an
element matches :root if it is the documentElement of its ownerDocument.
-Boris
