Recently, on some sites, black squares have appeared, blinking in a chaotic manner. Moreover, they are not always there. At first I thought it was some advertising bugs. However, I decided to play around with CSS-animation, and now I saw them on my test, local page. 
#bodyWrap{ .clear(); width: 3000px; height: 100%; background-image: url("../img/bg.jpg"); background-size: 2500px 100%; background-position:0px top; background-repeat: repeat-x; animation: bg; animation-duration: 90s; animation-iteration-count: infinite; animation-timing-function: linear; } @keyframes bg{ 0% { background-position:0px top; } 100% { background-position:-1500px top; } } I use Chrome Version 66.0.3359.181. In Mozilla, it seems to be no. Why do these squares appear? Are they only connected with the browser or does the power of the computer still matter?
