body {
  margin: 0;
  background: #000; 
}

video { 
    position: fixed;
    top: 50%;
    left: 50%;
    min-width: 100%;
    min-height: 100%;
    width: auto;
    height: auto;
    z-index: -100;
    transform: translateX(-50%) translateY(-50%);
    background: url('../videos/bg-face.jpg') no-repeat;
    background-size: cover;
    transition: 1s opacity;
}

@media screen and (max-width: 500px) { 
  div{width:70%;} 
}

@media screen and (max-device-width: 800px) {
  html { background: url('../videos/bg-face.jpg') #000 no-repeat center center fixed; }
  #bgvid { display: none; }
}