[css3-selectors] "recursive" selectors

Was just playing around with some ideas, and was wondering if/why can't 
CSS3 selectors select based on CSS properties? A useful example of what 
I'm talking about might be something like:

    *:style(display: block) { margin: auto; }

I suppose you could do something like:

    *[style*="display: block"] { margin: auto; }

But that's obviously not as robust as the previous example/proposal.

As far as I know there isn't any better way of achieving something like 
this (centering all block-level elements), but should be in my opinion.

- Andy