Is there any plan to handle the equivalent of :focus-within for the :focus-visible pseudo-selector in the CSS spec? Something like :focus-visible-within?

I modified [my version of] the script to add the focus-visible class to the body whenever focus is visible. Then I can write a selector like body.focus-visible foo:focus-within to style foo when focus is visible within it, but I don't see an obvious way to do that in pure CSS once the spec is updated.