Re: The :min-width/:max-width pseudo-classes

On 3/22/13 1:30 PM, Tab Atkins Jr. wrote:
> It would be a property that switches it into "viewport mode", where
> its intrinsic size is no longer dependent on its children.  (No cyclic
> dependencies, because the viewport-element-relative pseudos can't
> apply to the subject of the selector.)

That's still really bad.

In particular, it means that you have to serialize style computation on 
a parent and CSS selector matching on its kids, because you can't do the 
latter until you've done the former and determined whether the parent 
has a magic property.

And that means that any hope of parallelizing selector matching across 
the tree is pretty much dead....

-Boris