body {max-width: 40em; margin: auto;
      font-family: helvetica; 
      line-height: 1.5em;
      text-align: justify;
      font-family: Verdana,Arial,'Lucida Grande',Sans-Serif;
      }
      .anchor { margin-left: 0.5em; }
      .by { float: right; }
      .clear { clear: both; }
      .halfvisible { opacity: 0.5; }
      .invisible {opacity: 0.01; }
      img {max-width: 100%;}
      h1 { margin-top: 3em; }
      h2 { margin-top: 2em; }
      h3 { margin-top: 1em; }
      h1.title { margin-top: 0.75em; }
      h1.btop { border-top: solid 3px black; padding-top: 0.55em; }
      @media print { .anchor, .halfvisible, .invisible { visibility: hidden; } }
      .red { color: #ff0000 }
      .green { color: #00d400 }
      .blue  { color: #0000ff }
      figure { text-align: center; }
      figcaption { margin-bottom: 3em; }
      .result { border: solid 1px black; }