That’s badly broken in a variety of ways at a variety of window sizes in both Firefox and Chromium, though worse in Firefox where it goes from being unpleasant to downright unusable at some sizes; and at larger resolutions in Firefox it’s not even managing 3fps. What are you doing? You’re meddling with scrolling, too. :-(
Also broken on iOS. Goes off my viewport horizontally. Scroll doesn’t work as expected.
There is scroll snapping. Yes it slightly exceeds the horizontal. My point was about the CSS Painting API though :)
Solved the horizontal viewport.
I am not seeing any issues on Chrome. To be fair, I mostly cared about Safari and Chrome than Firefox.