pre { 
      text-align: left; 
      /* background: whitesmoke; */
      white-space: pre-wrap;
      word-break: break-all;
    }
    img  {
      display: block;
      margin-left: auto;
      margin-right: auto;
    }
  @media screen and (max-width: 680px) {
    iframe {
        max-width: 100% !important;
        width: auto !important;
        height: auto !important;
     }
    }