遮罩层

全屏遮罩层

.zhezhao {
      position: absolute;
      width: 150px;
      top: 0;
      z-index: 30;
      background-color: rgba(0,0,0,0.8);
      padding: 15px;
    ｝
    
 /*全屏*/
div {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0,0,0,0.5);
}