:root {
  --bg: #f6f7fb; --card: #fff; --text: #0f172a; --muted: #64748b;
  --primary: #4f46e5; --primary-hover: #4338ca;
  --border: #e2e8f0; --error-bg: #fef2f2; --error-fg: #b91c1c;
}
* { box-sizing: border-box; }
html, body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; background: var(--bg); color: var(--text); }
.auth-shell { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.auth-card {
  background: var(--card); border-radius: 16px; padding: 40px;
  box-shadow: 0 10px 40px rgba(15,23,42,0.06); width: 100%; max-width: 420px;
}
.auth-logo { text-align: center; margin-bottom: 28px; }
.logo-mark {
  width: 48px; height: 48px; margin: 0 auto 12px;
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  border-radius: 12px;
}
.auth-logo h1 { font-size: 1.4rem; margin: 0 0 4px; }
.muted { color: var(--muted); font-size: 0.9rem; margin: 0; }
.alert { padding: 12px 14px; border-radius: 8px; font-size: 0.9rem; margin-bottom: 16px; }
.alert-error { background: var(--error-bg); color: var(--error-fg); }
.auth-form label { display: block; margin-bottom: 14px; }
.auth-form label span { display: block; font-size: 0.85rem; margin-bottom: 6px; color: var(--muted); }
.auth-form input[type=email], .auth-form input[type=password], .auth-form input[type=text] {
  width: 100%; padding: 11px 13px; border: 1px solid var(--border);
  border-radius: 8px; font-size: 0.95rem; background: #fff;
}
.auth-form input:focus { outline: 2px solid var(--primary); outline-offset: -2px; border-color: var(--primary); }
.twofa-toggle { margin-bottom: 16px; }
.twofa-toggle summary { cursor: pointer; color: var(--muted); font-size: 0.85rem; padding: 6px 0; }
.btn-primary {
  width: 100%; padding: 12px; background: var(--primary); color: #fff;
  border: none; border-radius: 8px; font-size: 0.95rem; font-weight: 600; cursor: pointer;
}
.btn-primary:hover { background: var(--primary-hover); }
.footnote { margin-top: 20px; padding-top: 20px; border-top: 1px solid var(--border); font-size: 0.8rem; color: var(--muted); text-align: center; }
.footnote code { background: #f1f5f9; padding: 1px 6px; border-radius: 4px; font-size: 0.85em; }