body,
html{
    font-family: Tahoma;
    overflow-x: hidden;
}
.video_cover video{
    width: 50%; 
    margin: auto;
    position: relative;
}
.video_cover::before{
    content: "";
    width: 30%;
    left: 0%;
    height: 100%;
    position: absolute;
    background: #fff;
    z-index: 10000000;
}
.video_cover{
    position: fixed;
    z-index: 10000;
    top: 0px;
    bottom: 0px;
    left: 0px;
    right: 0px;
    width: 100%;
    background: #fff;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}