#banner_video {
    max-width: 100%;
    width: 100%;
    margin: 0 auto;
    display: block;
}

@media only screen and (min-width: 600px) {
    #banner_video {
        max-width: 320px;
    }
}

@media only screen and (min-width: 768px) {
    #banner_video {
        max-width: 450px;
    }
}

@media only screen and (min-width: 992px) {
    #banner_video {
        max-width: 500px;
    }
}

@media only screen and (min-width: 1200px) {
    #banner_video {
        max-width: 800px;
    }
}