/* ── Page shell ── */
    html, body { height: 100%; overflow: hidden; }

    .auth-shell {
      display: flex;
      height: 100vh;
      width: 100vw;
      overflow: hidden;
    }

    /* ══ LEFT PANEL — branding ══ */
    .auth-left {
      width: 42%;
      flex-shrink: 0;
      background: linear-gradient(135deg, var(--surface-1) 0%, var(--surface-2) 100%);
      border-right: 1px solid var(--surface-3);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 3.5rem;
      position: relative;
      overflow: hidden;
    }

    /* subtle grid background */
    .auth-left::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image:
        linear-gradient(var(--surface-3) 1px, transparent 1px),
        linear-gradient(90deg, var(--surface-3) 1px, transparent 1px);
      background-size: 40px 40px;
      opacity: 0.25;
      pointer-events: none;
    }

    /* glowing orb */
    .auth-left::after {
      content: '';
      position: absolute;
      top: -120px;
      left: -120px;
      width: 400px;
      height: 400px;
      background: radial-gradient(circle, color-mix(in srgb, var(--brand-primary) 8%, transparent) 0%, transparent 70%);
      pointer-events: none;
    }

    .auth-brand {
      position: relative;
      z-index: 1;
    }

    .auth-logo-mark {
      display: flex;
      align-items: center;
      gap: 14px;
      margin-bottom: 3rem;
    }

    .auth-logo-icon img { width: 56px; height: 56px; border-radius: 12px; object-fit: cover; display: block; box-shadow: var(--shadow-md); }
    .auth-logo-icon {
      width: 56px;
      height: 56px;
      flex-shrink: 0;
    }

    .auth-logo-name {
      font-family: var(--font-heading);
      font-size: 24px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--text-primary);
    }

    .auth-logo-tag {
      font-size: 10px;
      font-family: var(--font-mono);
      color: var(--text-secondary);
      letter-spacing: 0.5px;
      margin-top: 2px;
      text-transform: uppercase;
    }

    .auth-headline {
      font-family: var(--font-heading);
      font-size: 34px;
      font-weight: 700;
      letter-spacing: -0.75px;
      line-height: 1.2;
      color: var(--text-primary);
      margin-bottom: 1.25rem;
    }

    .auth-headline span { color: var(--brand-primary); }

    .auth-subtext {
      font-size: 14.5px;
      color: var(--text-secondary);
      line-height: 1.6;
      max-width: 320px;
    }

    .auth-features {
      position: relative;
      z-index: 1;
      display: flex;
      flex-direction: column;
      gap: 1rem;
      margin-top: 3rem;
    }

    .auth-feature {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 13.5px;
      color: var(--text-secondary);
    }

    .auth-feature-dot {
      width: 28px;
      height: 28px;
      border-radius: 8px;
      background: var(--brand-gradient-soft);
      border: 1px solid var(--surface-3);
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      color: var(--brand-primary);
    }

    .auth-feature-dot svg { fill: currentColor; }

    .auth-footer-note {
      position: relative;
      z-index: 1;
      font-size: 11px;
      font-family: var(--font-mono);
      color: var(--text-muted);
    }

    /* ══ RIGHT PANEL — form ══ */
    .auth-right {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow-y: auto;
      padding: 2.5rem 2rem;
      background: var(--surface-0);
    }

    .auth-form-wrap {
      width: 100%;
      max-width: 400px;
    }

    /* Tab switcher */
    .auth-tabs {
      display: flex;
      background: var(--surface-2);
      border-radius: var(--btn-radius);
      padding: 4px;
      margin-bottom: 2rem;
      gap: 4px;
    }

    .auth-tab {
      flex: 1;
      text-align: center;
      padding: 0.55rem;
      border-radius: 6px;
      cursor: pointer;
      font-size: 13px;
      font-weight: 600;
      color: var(--text-secondary);
      transition: all var(--transition-fast);
      user-select: none;
    }

    .auth-tab.active {
      background: var(--surface-1);
      color: var(--text-primary);
      box-shadow: var(--shadow-sm);
    }

    /* Form heading */
    .auth-form-title {
      font-family: var(--font-heading);
      font-size: 22px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--text-primary);
      margin-bottom: 0.25rem;
    }

    .auth-form-sub {
      font-size: 13.5px;
      color: var(--text-secondary);
      margin-bottom: 2rem;
    }

    /* Panel visibility */
    .auth-panel { display: none; }
    .auth-panel.active { display: block; }

    /* Single-column form fields */
    .auth-fields {
      display: flex;
      flex-direction: column;
      gap: 1.25rem;
    }

    /* Two-column row inside form */
    .auth-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1rem;
      align-items: end;
    }

    /* Submit button */
    .auth-submit {
      width: 100%;
      justify-content: center;
      padding: 0.8rem;
      font-size: 14px;
      margin-top: 0.5rem;
      border-radius: var(--btn-radius);
    }

    /* Demo hint */
    .auth-demo-hint {
      margin-top: 1.5rem;
      text-align: center;
      font-size: 11px;
      color: var(--text-secondary);
      font-family: var(--font-mono);
      padding: 0.75rem 1rem;
      background: var(--surface-2);
      border-radius: var(--radius);
      border: 1px solid var(--surface-3);
    }

    .auth-demo-hint strong { color: var(--brand-primary); }

    /* Divider */
    .auth-divider {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      margin: 0.5rem 0;
      font-size: 11px;
      color: var(--text-muted);
      text-transform: uppercase;
      font-family: var(--font-mono);
      letter-spacing: 0.5px;
    }

    .auth-divider::before,
    .auth-divider::after {
      content: '';
      flex: 1;
      height: 1px;
      background: var(--surface-3);
    }

    /* ── Responsive Adjustments ── */
    @media (max-width: 900px) {
      html, body {
        overflow: auto;
        height: auto;
      }
      .auth-shell {
        flex-direction: column;
        height: auto;
        min-height: 100vh;
        overflow: visible;
      }
      .auth-left {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--surface-3);
        padding: 2rem 1.5rem;
        height: auto;
      }
      .auth-brand {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        width: 100%;
        gap: 1rem;
        flex-wrap: wrap;
      }
      .auth-logo-mark {
        margin-bottom: 0;
      }
      .auth-logo-icon img {
        width: 44px;
        height: 44px;
        border-radius: 10px;
      }
      .auth-logo-icon {
        width: 44px;
        height: 44px;
      }
      .auth-logo-name {
        font-size: 18px;
      }
      .auth-logo-tag {
        font-size: 8px;
      }
      .auth-headline,
      .auth-subtext,
      .auth-features,
      .auth-footer-note {
        display: none;
      }
      .auth-mode-selector {
        margin-top: 0 !important;
        max-width: 100% !important;
        padding: 8px 10px !important;
      }
      .auth-right {
        width: 100%;
        padding: 3rem 1.5rem;
        height: auto;
      }
    }