#ssd {
    background-image: url(../images/ssd_1920.jpg);
    height: 780px;
}

@media screen and (max-width: 1366px) {
    #ssd {
        background-image: url(../images/ssd_1366.jpg);
        height: 620px;
    }
}

@media screen and (max-width: 960px) {
    #ssd {
        background-image: url(../images/ssd_960.jpg);
        height: 530px;
    }
}

@media screen and (max-width: 640px) {
    #ssd {
        background-image: url(../images/ssd_640.jpg);
        height: 950px;
        background-position: center bottom;
    }
}