body
{
    color: #000; background: #eee;
}
div.center
{
    text-align: center;
}
h1
{
    text-align: center;
}
div#main
{
    margin-left: auto;
    margin-right: auto;
    border: 1px solid black;
    padding: 1em;
    width: 50em;
    background: white;
}
pre
{
    margin-left: 4em;
    margin-right: 4em;
    padding: 1em;
    background: #eef;
}
table
{
    background: #eef;
    border-collapse: collapse;
    font-family: monospace;
    font-size: small;
}
td
{
    padding-left: .5em;
    padding-right: .5em;
}