:root { color-scheme: light; }
* { box-sizing: border-box; }
body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: #f4f6f8;
  margin: 0;
  padding: 24px 16px;
  color: #1a1a1a;
}
.card {
  max-width: 420px;
  margin: 0 auto;
  background: #fff;
  border-radius: 12px;
  padding: 28px 24px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.06);
}
h1 { font-size: 20px; margin: 0 0 8px; }
p.sub { color: #666; margin: 0 0 24px; font-size: 14px; }
label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; }
input[type=text], input[type=email], input[type=password] {
  width: 100%;
  padding: 11px 12px;
  border: 1px solid #d7dbe0;
  border-radius: 8px;
  font-size: 15px;
  margin-bottom: 16px;
}
button {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 8px;
  background: #16a34a;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}
button:disabled { background: #9ca3af; cursor: not-allowed; }
.step { display: none; }
.step.active { display: block; }
.qr-box { text-align: center; margin: 8px 0 20px; }
.qr-box img { width: 240px; height: 240px; border: 1px solid #eee; border-radius: 8px; }
.status-line { text-align: center; font-size: 14px; color: #555; margin-top: 8px; }
.token-box {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-radius: 8px;
  padding: 14px;
  font-family: ui-monospace, monospace;
  font-size: 13px;
  word-break: break-all;
  margin: 12px 0;
}
.warn {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 8px;
  padding: 12px;
  font-size: 13px;
  color: #92400e;
  margin-bottom: 16px;
}
.info {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  padding: 12px;
  font-size: 13px;
  color: #1e40af;
  margin-bottom: 16px;
}
.error { color: #b91c1c; font-size: 13px; margin-top: -8px; margin-bottom: 12px; }
.copy-btn { background: #111827; margin-top: 4px; }
.spinner {
  width: 18px; height: 18px; border: 2px solid #ddd; border-top-color: #16a34a;
  border-radius: 50%; display: inline-block; animation: spin 0.8s linear infinite; vertical-align: middle;
}
@keyframes spin { to { transform: rotate(360deg); } }

.tabs { display: flex; gap: 8px; margin-bottom: 20px; }
.tab-btn {
  flex: 1;
  background: #f1f3f5;
  color: #444;
  padding: 10px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 14px;
}
.tab-btn.active { background: #111827; color: #fff; }
.link-btn {
  background: none;
  color: #2563eb;
  font-size: 13px;
  font-weight: 500;
  width: auto;
  padding: 0;
  text-decoration: underline;
  margin-top: -8px;
  margin-bottom: 16px;
}