* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; display: grid; place-items: center;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: #f3f4f6; color: #111827; padding: 16px;
}
.card {
  background: #fff; max-width: 420px; width: 100%; padding: 32px;
  border-radius: 12px; box-shadow: 0 4px 20px rgba(0,0,0,.08);
}
h1 { font-size: 1.4rem; margin-top: 0; }
.actions { display: grid; gap: 12px; margin: 20px 0; }
.btn {
  display: block; text-align: center; padding: 12px; border-radius: 8px;
  border: 1px solid #d1d5db; background: #fff; color: #111827;
  text-decoration: none; font-weight: 600; cursor: pointer; width: 100%; font-size: 1rem;
}
.btn.github { background: #24292f; color: #fff; border-color: #24292f; }
.btn:hover { filter: brightness(.95); }
.note { font-size: .85rem; color: #6b7280; }
[hidden] { display: none !important; }