#play {
    background-image:url('/images/play-mobile@2x.png');
    -webkit-background-size: 125px 24px;}
    #sound #play.paused:active {
            background-position: -26px 0; }
    #sound #play.playing {
        background-position: -50px 0; }
    #sound #play.loading {
        background-position: -100px 0; }