:root {
  color-scheme: light dark;
  --bg: #fbf8f4;
  --card: #ffffff;
  --ink: #23302c;
  --muted: #5d6b66;
  --accent: #3f5e56;
  --line: #e3ddd4;
  --danger: #8c2f22;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #171b1a;
    --card: #1f2523;
    --ink: #eceae5;
    --muted: #a8b2ae;
    --accent: #8fb3a7;
    --line: #2f3835;
    --danger: #e5a094;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
main {
  width: 100%;
  max-width: 34rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 28px 24px;
}
h1 { margin: 0 0 12px; font-size: 1.4rem; line-height: 1.3; }
p { margin: 0 0 14px; }
.muted { color: var(--muted); font-size: 0.925rem; }
button {
  appearance: none;
  border: 0;
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  padding: 12px 22px;
  cursor: pointer;
  min-height: 48px;
}
button:disabled { opacity: 0.65; cursor: default; }
.note {
  margin-top: 18px;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  font-size: 0.925rem;
}
.error { color: var(--danger); border-color: var(--danger); }
[hidden] { display: none !important; }