body {
  font-family: sans-serif;
  line-height: 1.6;
  max-width: 800px;
  margin: auto;
  padding: 1rem;
  background-color: #f9f9f9;
  color: #333;
}

header {
  text-align: center;
  margin-bottom: 2rem;
}

nav {
  margin-top: 1rem;
}

nav a {
  margin: 0 15px;
  text-decoration: none;
  color: #0077cc;
  font-weight: bold;
}

nav a:hover {
  text-decoration: underline;
}

h1, h2, h3 {
  color: #004466;
}

pre {
  background: #eee;
  padding: 1em;
  overflow-x: auto;
}

footer {
  margin-top: 3rem;
  text-align: center;
  font-size: 0.9em;
  color: #777;
}