:root {
  --bg: #f3f4f6; --card: #ffffff; --text: #111827; --muted: #6b7280;
  --open: #16a34a; --close: #dc2626; --accent: #2563eb; --border: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #111827; --card: #1f2937; --text: #f9fafb; --muted: #9ca3af; --border: #374151; }
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; font-family: system-ui, sans-serif;
  background: var(--bg); color: var(--text);
  display: flex; justify-content: center; padding: 24px 16px;
}
main { width: 100%; max-width: 420px; display: flex; flex-direction: column; gap: 16px; }
h1 { margin: 0 0 8px; font-size: 1.6rem; text-align: center; }
button {
  width: 100%; padding: 32px 16px; border: none; border-radius: 16px;
  font-size: 1.5rem; font-weight: 600; color: #fff; cursor: pointer;
  transition: transform .05s, opacity .2s;
}
button:active { transform: scale(.98); }
button:disabled { opacity: .5; cursor: wait; }
#open { background: var(--open); }
#close { background: var(--close); }
button.primary { background: var(--accent); padding: 16px; font-size: 1.1rem; border-radius: 12px; }
button.link {
  background: none; color: var(--muted); padding: 8px; font-size: .9rem;
  font-weight: 400; text-decoration: underline;
}
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 12px; padding: 12px 16px;
}
#status { text-align: center; min-height: 1.4em; font-weight: 500; }
#status.error { color: var(--close); }
.hint { color: var(--muted); font-size: .85rem; text-align: center; }
ul { list-style: none; margin: 0; padding: 0; font-size: .9rem; }
li { padding: 4px 0; border-bottom: 1px solid var(--border); color: var(--muted); }
li:last-child { border-bottom: none; }
form { display: flex; flex-direction: column; gap: 12px; }
input[type=password] {
  width: 100%; padding: 14px; font-size: 1.1rem; border-radius: 12px;
  border: 1px solid var(--border); background: var(--card); color: var(--text);
}
label.check { display: flex; align-items: center; gap: 8px; color: var(--muted); }