body {
  margin: 0;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #0f1220;
  color: #fff;
  font-family: Arial, sans-serif;
}

.card {
  background: #1c1f3a;
  padding: 30px;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 10px 30px rgba(0,0,0,0.4);
}

button {
  margin-top: 15px;
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  background: #4f7cff;
  color: white;
  font-size: 16px;
}