body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f3f3f3;
  color: #333;
}

header {
  background: #222;
  color: white;
  text-align: center;
  padding: 1.5rem;
}

.card {
  background: white;
  margin: 1rem auto;
  padding: 1rem;
  border-radius: 10px;
  max-width: 600px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

footer {
  text-align: center;
  padding: 1rem;
  background: #ddd;
}