@media screen and (min-width: 400px)
 {

    video {
    position: fixed; right: 0; bottom: 0;
    min-width: 100%; min-height: 100%;
    width: auto; height: auto; z-index: -100;
    background-size: cover;
    }

 }

@media only screen and (max-width : 400px) {
background: url(../images/tanisalimmobilebackground.jpg);
    background-size:cover;

    video {
        display:none!important;
    }

}

@media only screen and (max-width : 400px) {
    someelement{
        background: url(../images/tanisalimmobilebackground.jpg);
        background-size:cover;
    }
    video {
        display:none!important;
    }

}