#background_video {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    object-fit: cover;
    height: 100%;
    width: 100%;
}

#video_cover {
    position: absolute;
    width: 100%;
    height: 100%;
    background: url('https://cdn.xt12366.com/image/xtshsw/2021/index/video-banner-bg.png') no-repeat;
    background-size: cover;
    background-position: center;
}

#overlay {
    position: absolute;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
}