[css-cascade-4] An "all-namespaces" user agent stylesheet #8573
Description
Right now we have:
But some styles should span all three, for example view transition pseudo-element styles, but perhaps also things like ::selection.
It feels like we need a central "all-namespaces user agent stylesheet". Other specs could define a set of styles, and the central "all-namespaces user agent stylesheet" spec would include them (this would also define the ordering of styles from different specs).