gistfile1.css

dl.expand{
  float: left; display: inline;
  width: 315px;
  margin: 0 20px 14px 0;
  &:nth-child(even){ margin-right: 0; }
  dt{ 
    border-bottom: 1px solid #fff; 
    position: relative; 
    cursor: pointer; 
    h3{ margin: 0; border-bottom: 1px solid #cecece; }
    span.action{ 
      position: absolute; top: 0; right: 10px; 
      display: block; 
      width: 16px; height: 16px;
      background: #fff url(../images/expand-closed.png) 0 0 no-repeat;
      text-indent: -9999px; overflow: hidden; 
    }
  }
  &.open span.action{ background: #fff url(../images/expand-open.png) 0 0 no-repeat; }
  dd{ padding: 14px 10px 0 10px; display: none; }
  &.open dd{ display: block; }
}