:root {
  color-scheme: light dark;
  --fg: #111;
  --bg: #fafafa;
  --card: #fff;
  --accent: #2563eb;
  --ok: #15803d;
  --warn: #b45309;
  --err: #b91c1c;
  --border: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --fg: #f1f5f9;
    --bg: #0f172a;
    --card: #1e293b;
    --border: #334155;
  }
}
* { box-sizing: border-box; }
html, body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--fg);
  font-size: 16px;
}
main {
  max-width: 480px;
  margin: 0 auto;
  padding: 16px;
}
h1 { font-size: 1.4rem; margin: 8px 0 16px; }
h2 { font-size: 1.1rem; margin: 16px 0 8px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
}
label { display: block; font-size: 0.9rem; margin-bottom: 4px; }
input[type=text], input[type=password] {
  width: 100%;
  padding: 12px;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--fg);
}
button {
  width: 100%;
  padding: 14px;
  font-size: 1rem;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  margin-top: 8px;
}
button.secondary { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
button.green { background: var(--ok); }
button.green.secondary { background: transparent; color: var(--ok); border: 1px solid var(--ok); }
button:disabled { opacity: 0.5; }
.qr { display: flex; justify-content: center; padding: 16px; background: white; border-radius: 12px; }
.qr img, .qr canvas { width: 100%; max-width: 320px; height: auto; }
.muted { color: #6b7280; font-size: 0.85rem; }
.status { padding: 12px; border-radius: 8px; margin: 8px 0; font-weight: 500; }
.status.ok { background: rgba(21, 128, 61, 0.15); color: var(--ok); }
.status.warn { background: rgba(180, 83, 9, 0.15); color: var(--warn); }
.status.err { background: rgba(185, 28, 28, 0.15); color: var(--err); }
nav a { display: inline-block; margin-right: 12px; color: var(--accent); }
#reader { width: 100%; }
table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
th, td { text-align: left; padding: 8px 4px; border-bottom: 1px solid var(--border); }
ul.signins { list-style: none; padding: 0; margin: 0; }
ul.signins li { padding: 8px 0; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; }