The following is an example styled with the "example" class. Here is the CSS code.
.example { background-color: #d5dee3;
border-top-width: 4px;
border-top-style: double;
border-top-color: gray;
border-bottom-width: 4px;
border-bottom-style: double;
border-bottom-color: gray;
padding: 4px; margin: 1em
the spec prose continues ...