video{
    position: fixed;
    display: block;
    width: 100%;
    object-fit:fill;
    height:100%;
    right: 0px;
    bottom: 0px;
    top: 0px;
    left: 0px;
    z-index: -11;
  }
  source{
    min-width: 100%;
    min-height: 100%;
    height: auto;
    width: auto;
  }

　　

<video id='video'  autoplay loop muted>
      <source src="../../assets/img/bgvideo.mp4" type="video/mp4"  />
      Your browser does not support the video tag.
 </video>