Retina Mixin

retina.scss

@mixin retina() {
	@media only screen and (-webkit-min-device-pixel-ratio: 1.25),
				 only screen and (min-resolution: 120dpi) {
		 @content;
	}
}

.icon {
	background-size: 200px 40px;
	background-image: url(img/icons.png);
	@include retina() {
		background-image: url(img/icons-2x.png);
	}
	
}