jquery实现直播视频弹幕效果

    html, body {
      margin: 0px;
      padding: 0px;
      width: 100%;
      height: 100%;
      font-family: "微软雅黑";
      font-size: 62.5%;
    }
 
    .boxDom {
      width: 100%;
      height: 100%;
      position: relative;
      overflow: hidden;
    }
 
    .idDom {
      width: 100%;
      height: 10%;
      background: #666;
      position: fixed;
      bottom: 0px;
    }
 
    .content {
      display: inline-block;
      width: 460px;
      height: 40px;
      position: absolute;
      left: 0px;
      right: 0px;
      top: 0px;
      bottom: 0px;
      margin: auto;
    }
 
    .title {
      display: inline;
      font-size: 4em;
      vertical-align: bottom;
      color: #fff;
    }
 
    .text {
      border: none;
      width: 300px;
      height: 30px;
      border-radius: 5px;
      font-size: 2.4em;
    }
 
    .btn {
      width: 60px;
      height: 30px;
      background: #f90000;
      border: none;
      color: #fff;
      font-size: 2.4em;
    }
 
    span {
      height: 40px;
      position: absolute;
      overflow: hidden;
      color: #000;
      font-size: 4em;