It's been brought up a few times before, most recently in #5911, that it would be useful to set snapping controls on the individual columns of a multi-column element to enable, for example, using multicol as a pagination mechanism with snapping between "pages".

The most straightforward way to do this would be to add a pseudo-element (e.g. ::column or ::nth-column(An+B) that represents each column. It could initially accept only the properties in css-scroll-snap, though we'll likely want to extend it to accept other properties in the future as well.

Thoughts?

p.s. With a generic name like that, though, we'll have to contend with also the question of whether to extend this to grid tracks, flex lines, and/or table rows and columns. (It's not so necessary to have this feature there, because they typically have elements we can snap to instead.)