body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  padding: 20px;
  max-width: 900px;
  margin: auto;
}
header {
  text-align: center;
  margin-bottom: 30px;
}
h1 {
  font-size: 2.5rem;
  margin: .2rem 0;
}
nav a {
  margin: 0 10px;
}
section {
  margin: 2rem 0;
}
footer {
  text-align: center;
  margin-top: 40px;
  font-size: 0.9rem;
  color: #555;
}