/* REPLACEMENTS */
  SPAN.r {color: red; background: white} /* replacement */
  SPAN.i {color: yellow; background: white} /* insertion */
  SPAN.m {color: blue; background: white; font-size: 50%;
     font-family: Helvetica } /* meta-data */
  SPAN.m:before {content: "[[ "; }
  SPAN.m:after {content: " ]]"; }
    /* does not work on my browser */