body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #eef2ff, #dbeafe);
  color: #1f2937;
}

.card {
  width: min(90vw, 24rem);
  padding: 2rem;
  border-radius: 1rem;
  text-align: center;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 1rem 2rem rgba(15, 23, 42, 0.15);
}

button {
  border: 0;
  padding: 0.85rem 1.5rem;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: #2563eb;
  cursor: pointer;
}

button:hover {
  background: #1d4ed8;
}