body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f5f5f5;
}
header {
  background: #222;
  color: white;
  padding: 2rem;
  text-align: center;
}
section {
  padding: 2rem;
  background: white;
  margin: 1rem;
  border-radius: 8px;
}
footer {
  background: #333;
  color: white;
  text-align: center;
  padding: 1rem;
}
a { color: #007bff; }