body {
    background-color: black;
}

.main {
    background: url('/beastsvsrobots/images/bvr.jpeg') ;
    background-size: contain;
    background-repeat: no-repeat;
    width: 100%;
    height: 0;
    padding-top: 96%;
}


@media screen and (max-width: 668px) {
    .main {


        background: url('/beastsvsrobots/images/fondobeasts.jpeg') ;
        background-size: contain;
        background-repeat: no-repeat;
        width: 100%;
        height: 0;
        padding-top: 179%;


    }

}