body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: #f4f6f8;
  color: #1f2937;
}

header {
  background-color: #1d4ed8;
  color: white;
  text-align: center;
  padding: 40px 20px;
}

main {
  max-width: 900px;
  margin: 30px auto;
  padding: 0 20px;
}

.card {
  background: white;
  padding: 24px;
  margin-bottom: 20px;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

footer {
  text-align: center;
  padding: 20px;
  background-color: #e5e7eb;
  margin-top: 40px;
}