Retina displays CSS background image

style.css

.logo_background {
    background-image: url('../img/logo@1x.png');
    background-position: center center;
    background-repeat: no-repeat;
    background-size: 80px 40px; /* size of the logo image @ 1x */
}
@media /* only for retina displays */
only screen and (-webkit-min-device-pixel-ratio: 2),
only screen and (min--moz-device-pixel-ratio: 2),
only screen and (min-device-pixel-ratio: 2),
only screen and (-webkit-min-device-pixel-ratio: 2),
only screen and (min-resolution: 192dpi),
only screen and (min-resolution: 2dppx) {
    .logo_background {
        background-image: url('../img/logo@2x.png');
    }
}