body {
  font-family: Arial, sans-serif;
  background: #f4f6f8;
  margin: 0;
  color: #222;
}

header {
  background: #0c4b33;
  color: white;
  padding: 24px;
  text-align: center;
}

main {
  max-width: 700px;
  margin: 24px auto;
  padding: 0 16px;
}

.card {
  background: white;
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 16px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}

button {
  background: #0c4b33;
  color: white;
  border: none;
  padding: 10px 16px;
  border-radius: 6px;
  cursor: pointer;
}

button:hover {
  background: #146b49;
}

.error {
  color: #b00020;
  font-weight: bold;
}

footer {
  text-align: center;
  color: #777;
  padding: 16px;
}