body {
  background: white;
  color: black;
  margin: 2em;
  font-family: "Times New Roman", Times, serif;
  font-size: 16px;
  line-height: 1.5;
}

a:link    { color: blue; }
a:visited { color: purple; }
a:active  { color: red; }

nav {
  float: left;
  width: 120px;
  margin-right: 2em;
}

nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

nav li {
  margin-bottom: 0.25em;
}

nav .here {
  font-weight: bold;
}

main {
  margin-left: 152px;
  max-width: 640px;
}

h1 {
  font-size: 1.2em;
  font-weight: bold;
  margin-top: 0;
}

ul.plain {
  list-style: none;
  padding-left: 0;
}

ul.plain li {
  margin-bottom: 0.4em;
}

@media (max-width: 600px) {
  body { margin: 1em; }
  nav {
    float: none;
    width: auto;
    margin-right: 0;
    margin-bottom: 1.5em;
    border-bottom: 1px solid #ccc;
    padding-bottom: 0.5em;
  }
  nav li {
    display: inline;
    margin-right: 1em;
  }
  main {
    margin-left: 0;
  }
}