Retina media query implementation

retina.css

.sprite.logo {
    background: url(logo.png);
    width: 200px;
    height: 80px;
}

@media
    only screen and (min-device-pixel-ratio: 2),
    only screen and (-webkit-min-device-pixel-ratio: 2),
    only screen and (-moz-min-device-pixel-ratio: 2),
    only screen and (-o-min-device-pixel-ratio: 2/1) {
        .sprite.logo {
            background: url(logo-2x.png);
            background-size: 200px 80px;
        }
}