I want the ability to flip element scroll orientation (to create text message-like interfaces)

Mobile UIs have settled on a pattern in text message-like conversations where the latest item appears at the bottom of the screen and pushes new items upwards. That's very difficult to replicate on the web without heavy JavaScript use to set the scroll position manually (which can then clash with a user trying to scroll themselves). It would be great to flip an element's scroll orientation entirely, with new items appearing at the bottom and scroll position being pinned to the bottom.

It's possible to get quite far towards this with a CSS rotate and right-to-left hack, but it doesn't work on iOS and isn't semantically correct anyway.