body { margin-left: 5%; margin-right: 5%;
        font-family: sans-serif,Arial, Helvetica;
      }

   H1, H2, H3, H4  {color:blue;
                    font-family: sans-serif;
                   }

   pre { font-family: monospace; background: lightblue;}

  div.color {
                background: yellow;
                padding: 0.5em;
                border: none;
              }