.section {
  background-color: fuchsia;
  top:15px;
  margin-top:15px;
}
.changes {
  background-color: #CCC;
}
pre {
overflow: hidden;
}
pre.new {
        position: relative;
        background-color: #0f0;
        font-size: small;
        width: 500px;
}

pre.old {
     position: relative;
        background-color: #ff0;
        font-size: small;
        width: 500px;
}