#background-box {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    z-index: -2;
}

#background-box #video-src {
    min-width: 100%;
    min-height: 100%;
    width: auto;
    height: auto;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}
