:root { color-scheme: light dark; }

body {
  margin: 0;
  min-height: 100vh;
  padding: 2.5rem 1.25rem;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #fafafa;
  color: #1a1a1a;
}

@media (prefers-color-scheme: dark) {
  body { background: #111214; color: #f1f1f1; }
}

.back {
  display: inline-block;
  margin-bottom: 1.5rem;
  font-size: 0.85rem;
  opacity: 0.7;
  text-decoration: none;
  color: inherit;
}

main {
  max-width: 560px;
  margin: 0 auto;
}

button {
  padding: 0.6rem 1.1rem;
  border-radius: 8px;
  border: 1px solid #2563eb;
  background: #2563eb;
  color: #fff;
  font-size: 0.95rem;
  cursor: pointer;
}