Bernd 11/27/2018 (Tue) 00:20:21 No.20810 del
>>20797
It is base64 of file contents embedded in stylesheet. Browsers can open them in URLs too, you may try to paste this into url bar:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAATCAYAAACk9eypAAAABGdBTUEAALGPC/xhBQAAAMFJREFUOE+NUsERwjAMy7w8WIHOwDCdpQ92MZYiO05KAd0plmOpzaVtZjbRYU8R+jSfGm93bB2d0GtoCJd4apiD65v6Us1ABKRr6GwGagAoIQamIbAGAO9HQBt2KzoC2JPOwLZtHPBoQAlwz2fwzIGK+gYhA64ZStMF6anX+g+nQDxFA6L2qlxdXxuB0nuBGGckoNc+qrMHfh0JUD8CSWBXbS9e6fdrFfir6+vTg4Kl916WAPBo9zSDXLLx9hOHx9obgGI1NPcWwOgAAAAASUVORK5CYII=

>>20803
Yes, that's sad that they don't compress it. I guess the reason is that custom.css is the customized thing for each board that resides in database or somewhere like this, so they serve it with specific code.

Main downside of data-uri is that there are all countryballs in css, but only few balls actually required to display average page. Most of balls are never used. Although nowadays it is not really matter because few images on page already kill all size optimizations of css, and endchan is imageboard full of images.