CSS for swapping hi-res background images.

hi-res.css

/* 
-----------------------------------------------------------------------------
 =High Resolution Images
----------------------------------------------------------------------------- */
@media screen and (-webkit-min-device-pixel-ratio: 1.3),
screen and (min--moz-device-pixel-ratio: 1.3),
screen and (-o-min-device-pixel-ratio: 2 / 1),
screen and (min-device-pixel-ratio: 1.3),
screen and (min-resolution: 192dpi),
screen and (min-resolution: 2dppx) {
	#site-name a {
		background-image: url(/images/common/bg-logo-2x.png);
		-webkit-background-size: 303px 25px;
		-moz-background-size: 303px 25px;
		-o-background-size: 303px 25px;
		background-size: 303px 25px;
		}
}