body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: #111;
  color: #fff;
}

header {
  background: #222;
  padding: 20px;
  text-align: center;
}

nav a {
  color: #fff;
  margin: 0 15px;
  text-decoration: none;
}

.container {
  padding: 40px;
  max-width: 900px;
  margin: auto;
}

footer {
  background: #222;
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
}