@media only screen and (-webkit-min-device-pixel-ratio:2),only screen and (min-device-pixel-ratio:2){.replace-2x{font-size:1px}.example{background-image:url(data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==);-webkit-background-size:13px 13px;-moz-background-size:13px 13px;-o-background-size:13px 13px;background-size:13px 13px}}