top: 1.2em;
  }
  pre.src:before {
    display: none;
    position: absolute;
    background-color: white;
    top: -10px;
    right: 10px;
    padding: 3px;
    border: 1px solid black;
  }
  pre.src:hover:before { display: inline;}
  pre.src-sh:before    { content: 'sh'; }
  pre.src-bash:before  { content: 'sh'; }
  pre.src-emacs-lisp:before { content: 'Emacs Lisp'; }
  pre.src-R:before     { content: 'R'; }
  pre.src-perl:before  { content: 'Perl'; }
  pre.src-java:before  { content: 'Java'; }
  pre.src-