First Line Pseudo Element in epubs

Hey ya'll, so I am in the midst of a trying to figure something out with the css of my epubs. (for background info, I have a kobo sage)

I really like my the first line of the first paragraphs in chapter/section to have "font-variant: small-caps" using first-line pseudo element, I also like to have page breaks before subheadings/section titles when they occur in the middle of a chapter.

My dilemma is this: I understand kepubs do not support page breaks, and epubs do, but one thing I have not been able to figure out is if epubs support the pseudo element first-line. I know for sure kepubs do, as I've had that working for a while, but I haven't been able to get first-line working on epubs..... Is there a way to get this to work?

edit to add in case it matters, these are all epub3s....