body {
    margin: 0;
    padding: 0;
}

video {
    display: block;
    margin: auto;
    width: 640px;
    height: 480px;
}

@media screen and (min-width: 960px) {
    video {
        width: 960px;
        height: 720px;
    }
}

@media print {
    video {
        display: none;
    }
}