  background-color: #f2f2f2;
    padding: 8pt;
    font-family: monospace;
    overflow: auto;
    margin: 1.2em;
  }
  pre.src {
    position: relative;
    overflow: auto;
  }
  pre.src:before {
    display: none;
    position: absolute;
    top: -8px;
    right: 12px;
    padding: 3px;
    color: #555;
    background-color: #f2f2f299;
  }
  pre.src:hover:before { display: inline; margin-top: 14px;}
  /* Languages per Org manual */
  pre.src-asymptote:before { content: 'Asymptote'; }
  pre.src-awk:before 