body {
  font-family: Arial, sans-serif;
  max-width: 700px;
  margin: auto;
  padding: 20px;
  background: #f9f9f9;
  color: #333;
}
header {
  text-align: center;
  margin-bottom: 30px;
}
nav a {
  margin: 0 10px;
  text-decoration: none;
  color: #0077cc;
}
footer {
  text-align: center;
  margin-top: 40px;
  font-size: 0.9em;
  color: #888;
}