#OC {
    background-color: #000;
    background-image: url(../images/OC-1920.jpg);
    background-position: 50% 70px;
    background-repeat: no-repeat;
    min-height: 884px;
}

@media screen and (max-width: 1366px) {
    #OC {
        background-color: #000;
        background-image: url(../images/OC-1366.jpg);
        background-position: center 20px;
        background-repeat: no-repeat;
        min-height: 811px;
    }
}

@media screen and (max-width: 960px) {
    #OC {
        background-image: url(../images/OC-960.jpg);
        background-position: center 0px;
        background-repeat: no-repeat;
        min-height: 681px;
    }
}

@media screen and (max-width: 640px) {
    #OC {
        background-image: url(../images/OC-640.jpg);
        background-position: center -100px;
        background-repeat: no-repeat;
        min-height: 800px;
    }
}