body {
  font-family: sans-serif;
}
header > nav, footer > nav {
    text-align: center
}
header > nav > a[rel=prev], footer > nav > a[rel=prev] {
    float: center;
}
header > nav > a[rel=next], footer > nav > a[rel=next] {
    float: center;
}
header > hgroup > h1, header > hgroup > h2 {
  text-align: center;
}
p.copyright, p.start, p.subtitle, p.suptitle {
  text-align: center;
}
section, p.warning {
    width: 75%;
    margin: auto;
}
section > nav {
    width: 50%;
    margin: auto;
}
section > h3 {
  text-align: center;
  margin-top: 4.0em;
  margin-bottom: 0;
}