.auth-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-10) var(--space-6);
    position: relative;
    overflow: hidden;
  }

  /* ═══ Animated Background ═══ */
  .auth-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 0;
  }

  .auth-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.35;
    animation: authOrbFloat 18s ease-in-out infinite;
  }

  .auth-orb-1 {
    width: 500px;
    height: 500px;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    top: -180px;
    right: -120px;
  }

  .auth-orb-2 {
    width: 350px;
    height: 350px;
    background: linear-gradient(135deg, #3b82f6, #6366f1);
    bottom: -100px;
    left: -80px;
    animation-delay: -8s;
  }

  .auth-orb-3 {
    width: 250px;
    height: 250px;
    background: linear-gradient(135deg, #ec4899, #f43f5e);
    top: 40%;
    left: 60%;
    animation-delay: -4s;
    opacity: 0.15;
  }

  @keyframes authOrbFloat {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -25px) scale(1.06); }
    66% { transform: translate(-15px, 15px) scale(0.94); }
  }

  .auth-grid-lines {
    position: absolute;
    inset: 0;
    background-image:
      linear-gradient(rgba(99, 102, 241, 0.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(99, 102, 241, 0.04) 1px, transparent 1px);
    background-size: 50px 50px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 75%);
  }

  /* ═══ Container & Card ═══ */
  .auth-container {
    width: 100%;
    max-width: 420px;
    position: relative;
    z-index: 1;
  }

  .auth-card {
    padding: var(--space-10);
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: blur(24px) saturate(1.5);
    -webkit-backdrop-filter: blur(24px) saturate(1.5);
    border: 1px solid rgba(255, 255, 255, 0.6);
    border-radius: var(--radius-2xl);
    margin-bottom: var(--space-6);
    box-shadow:
      0 8px 32px rgba(0, 0, 0, 0.06),
      0 2px 8px rgba(0, 0, 0, 0.04),
      inset 0 1px 0 rgba(255, 255, 255, 0.8);
    animation: cardEntrance 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  /* Dark mode glassmorphism */
  html:not(.light-mode) .auth-card {
    background: rgba(15, 15, 25, 0.72);
    border-color: rgba(255, 255, 255, 0.08);
    box-shadow:
      0 8px 32px rgba(0, 0, 0, 0.3),
      0 2px 8px rgba(0, 0, 0, 0.2),
      inset 0 1px 0 rgba(255, 255, 255, 0.05);
  }

  @keyframes cardEntrance {
    from {
      opacity: 0;
      transform: translateY(24px) scale(0.97);
    }
    to {
      opacity: 1;
      transform: translateY(0) scale(1);
    }
  }

  /* ═══ Logo ═══ */
  .auth-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-3);
    margin-bottom: var(--space-8);
    text-decoration: none;
  }

  .logo-mark {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .logo-mark svg {
    width: 32px;
    height: 36px;
  }

  .logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1;
    gap: 1px;
  }

  .logo-traffic {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: 0.14em;
    text-transform: uppercase;
  }

  .logo-orchestrator {
    font-size: 0.8rem;
    font-weight: 500;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 0.02em;
  }

  /* ═══ Title ═══ */
  .auth-title {
    font-size: var(--text-2xl);
    font-weight: var(--font-bold);
    text-align: center;
    margin-bottom: var(--space-2);
    color: var(--text-primary);
  }

  .auth-subtitle {
    text-align: center;
    color: var(--text-tertiary);
    margin-bottom: var(--space-8);
  }

  /* ═══ OAuth Buttons ═══ */
  .oauth-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
  }

  .oauth-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-3);
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: rgba(255, 255, 255, 0.55);
    border: 1px solid rgba(0, 0, 0, 0.06);
    border-radius: var(--radius-lg);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(8px);
  }

  html:not(.light-mode) .oauth-btn {
    background: rgba(255, 255, 255, 0.04);
    border-color: rgba(255, 255, 255, 0.08);
  }

  .oauth-btn:hover {
    background: rgba(255, 255, 255, 0.85);
    border-color: rgba(99, 102, 241, 0.3);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  }

  html:not(.light-mode) .oauth-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.15);
  }

  /* ═══ Divider ═══ */
  .divider {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin: var(--space-6) 0;
  }

  .divider::before,
  .divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border-subtle);
  }

  .divider span {
    font-size: var(--text-xs);
    color: var(--text-quaternary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  /* ═══ Form ═══ */
  .form-group {
    margin-bottom: var(--space-5);
  }

  .form-group label {
    display: block;
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--text-primary);
    margin-bottom: var(--space-2);
  }

  .label-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-2);
  }

  .label-row label {
    margin-bottom: 0;
  }

  .forgot-link {
    font-size: var(--text-sm);
    color: var(--brand-primary);
    text-decoration: none;
  }

  .forgot-link:hover {
    text-decoration: underline;
  }

  .form-group input[type="email"],
  .form-group input[type="password"],
  .form-group input[type="text"] {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: rgba(255, 255, 255, 0.6);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: var(--radius-lg);
    font-size: var(--text-base);
    color: var(--text-primary);
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(8px);
  }

  html:not(.light-mode) .form-group input[type="email"],
  html:not(.light-mode) .form-group input[type="password"],
  html:not(.light-mode) .form-group input[type="text"] {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.1);
  }

  .form-group input:focus {
    outline: none;
    border-color: var(--brand-primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.12), 0 1px 3px rgba(0, 0, 0, 0.06);
    transform: translateY(-1px);
  }

  .form-group input::placeholder {
    color: var(--text-quaternary);
  }

  .password-wrapper { position: relative; }
  .password-wrapper input { padding-right: var(--space-10) !important; }
  .password-toggle {
    position: absolute; right: 12px; top: 50%; transform: translateY(-50%);
    background: none; border: none; padding: 4px; color: var(--text-tertiary);
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    transition: color 0.2s;
  }
  .password-toggle:hover { color: var(--text-primary); }

  /* ═══ Checkbox ═══ */
  .checkbox-group {
    margin-top: var(--space-2);
  }

  .checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: var(--text-sm);
    color: var(--text-secondary);
    cursor: pointer;
  }

  .checkbox-label input {
    display: none;
  }

  .checkmark {
    width: 18px;
    height: 18px;
    border: 2px solid var(--border-default);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--duration-fast);
  }

  .checkbox-label input:checked + .checkmark {
    background: var(--brand-primary);
    border-color: var(--brand-primary);
  }

  .checkbox-label input:checked + .checkmark::after {
    content: '✓';
    color: white;
    font-size: 12px;
  }

  /* ═══ Footer ═══ */
  .auth-footer {
    text-align: center;
    font-size: var(--text-sm);
    color: var(--text-tertiary);
    margin-top: var(--space-6);
  }

  .auth-footer a {
    color: var(--brand-primary);
    text-decoration: none;
    font-weight: var(--font-medium);
  }

  .auth-footer a:hover {
    text-decoration: underline;
  }

  /* ═══ Trust Row ═══ */
  .trust-row {
    display: flex;
    justify-content: center;
    gap: var(--space-6);
    flex-wrap: wrap;
  }

  .trust-item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-tertiary);
  }

  .trust-item svg {
    color: var(--text-quaternary);
  }

  /* ═══ Error States ═══ */
  .form-error-banner {
    padding: var(--space-3) var(--space-4);
    background: var(--error-muted);
    border: 1px solid rgba(239, 68, 68, 0.3);
    border-radius: var(--radius-lg);
    color: var(--error);
    font-size: var(--text-sm);
    margin-bottom: var(--space-5);
    display: flex;
    align-items: center;
    gap: var(--space-2);
  }

  .form-error-banner::before {
    content: '⚠';
  }

  .form-group input.input-error {
    border-color: var(--error);
  }

  .form-group input.input-error:focus {
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
  }

  .field-error {
    margin-top: var(--space-2);
    font-size: var(--text-sm);
    color: var(--error);
  }

  .label-required::after {
    content: ' *';
    color: var(--error);
  }

  /* ═══ Button Loading ═══ */
  .btn .btn-spinner {
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
  }

  @keyframes spin {
    to { transform: rotate(360deg); }
  }

  /* ═══ Reduced Motion ═══ */
  @media (prefers-reduced-motion: reduce) {
    .auth-orb { animation: none; }
    .auth-card { animation: none; }
  }