.ribbon {
    position: absolute;
    top: 0;
    right: 0;
    width: 150px;
    height: 22px;
    margin-right: -50px;
    margin-top: 15px;
    -ms-transform: rotate(45deg); /* IE 9 */
    -webkit-transform: rotate(45deg); /* Safari prior 9.0 */
    transform: rotate(45deg); /* Standard syntax */
  }