* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(135deg, #1f2937, #111827);
  color: #f3f4f6;
}

.card {
  background: #1e293b;
  padding: 2.5rem 3rem;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  text-align: center;
  max-width: 420px;
}

h1 {
  margin-top: 0;
  font-size: 1.8rem;
}

p {
  color: #cbd5e1;
  line-height: 1.5;
}

button {
  margin-top: 1rem;
  padding: 0.7rem 1.4rem;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  background: #6366f1;
  color: white;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.1s ease;
}

button:hover {
  background: #4f46e5;
}

button:active {
  transform: scale(0.97);
}