Created attachment 196537 [details]
html file demonstrating the bug
A specific combination of large fonts with fixed positioning causes stuttering, ugly artifacts, incorrect cropping and erroneous z-indexing. I've attached an html file to illustrate these problems.
Firefox and Chrome on desktop have no problem rendering the page. However, most mobile browsers break in some way, including webkit-backed ones. Some of the problems:
* The tiled background does not stay fixed
* Text on a lower z-index appears in front for some time, becomes correct after some sort of refresh occurs
* Artifacts appear after scrolling down pretty far, and scrolling back up
Created attachment 196538 [details]
video footage of broken page on mobile :(
This is video of interaction with Firefox, but Chrome reacts *very* similar.