html视频标签的使用＜video＞＜/video＞

html

css

.videoContainer{
  background-color: aqua;
  position: fixed;
  width: 100%;
  height: 100%;
  overflow: hidden;
  z-index: -100;
}

.videoContainer:before{
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  display: block;
  z-index: -1;
  top: 0;
  left: 0;
  background: rgba(25,29,34,.65);
}

效果