#march8 {

    height: 500px;
    background-image: url(../images/MAY_mob.png);
    background-size: 800px 500px;
    background-repeat:no-repeat;
    background-position: center center;

    @media (min-width: 800px) {
        background-image: url(../images/MAY_tab.png);
        background-size: 1200px 500px;
    }

    @media (min-width: 1200px) {
        margin-bottom: 10px;
        background-image: url(../images/MAU_desk.png);
        background-size: 1380px 500px;
    }

}