Weird glitch on my page??

Okay, so I've been screwing around with HTML and stuff on my profile the past few days, and after I started using this layout ( https://layouts.spacehey.com/layout?id=106503 ) my profile developed a weird glitch where if you scroll a bit, a bunch of white squares flash over half the page and make it really hard to read or see stuff. Anyone know how to fix it? I don't know where to even start.