body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  margin: 0;
  padding: 2rem;
  background: #f5f5f5;
}

h1 {
  margin-bottom: 2rem;
}

.card {
  background: white;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  margin-bottom: 1.5rem;
  max-width: 480px;
}

button {
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
}

pre {
  margin-top: 1rem;
  background: #111;
  color: #0f0;
  padding: 0.75rem;
  border-radius: 8px;
  min-height: 2.5rem;
  white-space: pre-wrap;
}