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

    /* ── Center Canvas ── */
    #center {
      flex: 1;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      background: var(--surface);
    }

    #canvas-wrap {
      flex: 1;
      position: relative;
      overflow: hidden;
      background: var(--surface);
    }

    #canvas-wrap::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: radial-gradient(circle, var(--outline-variant) 1px, transparent 1px);
      background-size: 28px 28px;
      opacity: 0.35;
      pointer-events: none;
      z-index: 0;
    }

    #cy {
      position: absolute;
      inset: 0;
      z-index: 1;
      background: transparent;
    }

    /* Empty state */
    #empty-state {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 1rem;
      z-index: 2;
      text-align: center;
      padding: 2rem;
    }

    .es-icon {
      width: 72px;
      height: 72px;
      background: var(--surface-low);
      border-radius: var(--radius-2xl);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2rem;
      box-shadow: var(--ambient-shadow);
    }

    .es-title {
      font-family: 'Manrope', sans-serif;
      font-size: 1.1rem;
      font-weight: 700;
      color: var(--on-surface);
    }

    .es-desc {
      font-size: 0.8rem;
      color: var(--outline);
      max-width: 220px;
      line-height: 1.5;
    }

    /* Canvas floating controls */
    .canvas-float {
      position: absolute;
      top: 12px;
      left: 50%;
      transform: translateX(-50%);
      z-index: 10;
      display: none;
    }

    .canvas-float.visible {
      display: block;
    }

    /* Ensure float-pill is visible in fullscreen */
    #canvas-wrap:fullscreen .canvas-float.visible,
    #canvas-wrap:-webkit-full-screen .canvas-float.visible {
      display: block;
      z-index: 9999;
    }

    .float-pill {
      display: flex;
      align-items: center;
      gap: 0.2rem;
      background: var(--surface-lowest);
      backdrop-filter: blur(16px);
      border-radius: var(--radius-full);
      padding: 0.35rem 0.7rem;
      box-shadow: var(--float-shadow);
      border: 1px solid var(--outline-variant);
    }

    .float-btn {
      width: 30px;
      height: 30px;
      border-radius: 50%;
      border: none;
      background: none;
      color: var(--on-surface-variant);
      font-size: 0.9rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: all var(--dur-fast);
    }

    .float-btn:hover {
      background: var(--surface-highest);
      color: var(--primary);
    }

    .float-btn svg {
      width: 15px;
      height: 15px;
    }

    .float-sep {
      width: 1px;
      height: 16px;
      background: var(--outline-variant);
      margin: 0 0.2rem;
      opacity: 0.5;
    }

    /* Zoom controls */
    .zoom-ctrl {
      position: absolute;
      bottom: 16px;
      right: 16px;
      z-index: 10;
      display: flex;
      flex-direction: column;
      gap: 0.3rem;
    }

    .zoom-btn {
      width: 32px;
      height: 32px;
      background: var(--surface-lowest);
      backdrop-filter: blur(12px);
      border: 1px solid var(--outline-variant);
      border-radius: var(--radius-md);
      color: var(--on-surface-variant);
      font-size: 1rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: all var(--dur-fast);
      box-shadow: var(--lift-shadow);
    }

    .zoom-btn:hover {
      background: var(--surface-high);
      color: var(--primary);
    }

    /* Canvas badge */
    .canvas-badge {
      position: absolute;
      top: 32px;
      right: 120px;
      z-index: 10;
      background: rgba(0, 91, 191, 0.1);
      color: var(--primary);
      font-size: 0.68rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      padding: 0.3rem 0.7rem;
      border-radius: var(--radius-full);
      display: none;
    }

    .canvas-badge.visible {
      display: block;
    }

    /* ε-closure popup */
    .closure-popup {
      position: absolute;
      background: var(--surface-lowest);
      border-radius: var(--radius-lg);
      padding: 0.8rem 1rem;
      box-shadow: var(--float-shadow);
      z-index: 20;
      display: none;
      min-width: 180px;
    }

    .closure-popup.visible {
      display: block;
      animation: fadeScaleIn var(--dur-fast) var(--ease-socialite);
    }

    .closure-title {
      font-family: 'Manrope', sans-serif;
      font-size: 0.78rem;
      font-weight: 700;
      color: var(--on-surface);
      margin-bottom: 0.3rem;
    }

    .closure-states {
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.78rem;
      color: var(--primary);
      font-weight: 600;
    }

    /* ── Floating Canvas Legend ── */
    .canvas-legend {
      position: absolute;
      bottom: 24px;
      left: 24px;
      padding: 0.65rem 0.8rem;
      background: var(--surface);
      border: 1px solid var(--outline-variant);
      border-radius: var(--radius-lg);
      box-shadow: var(--float-shadow);
      z-index: 100;
      display: flex;
      flex-direction: column;
      gap: 0.4rem;
      opacity: 0.95;
      animation: slideInRight 0.4s var(--ease-socialite);
    }

    .cl-row {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      font-size: 0.68rem;
      font-weight: 600;
      color: var(--on-surface-variant);
      letter-spacing: 0.02em;
    }

    .canvas-reset-wrap {
      position: absolute;
      top: 24px;
      right: 24px;
      z-index: 100;
    }

    .btn-canvas-reset {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.6rem 1rem;
      background: var(--surface);
      color: var(--tertiary);
      border: 1.5px solid var(--outline-variant);
      border-radius: var(--radius-full);
      font-family: 'Inter', sans-serif;
      font-size: 0.75rem;
      font-weight: 700;
      cursor: pointer;
      box-shadow: var(--float-shadow);
      transition: all 0.2s var(--ease-socialite);
    }

    .btn-canvas-reset:hover {
      background: var(--surface-high);
      border-color: var(--tertiary);
      transform: translateY(-1px);
    }

    .cl-symbol {
      width: 18px;
      height: 18px;
      border-radius: 50%;
      background: white;
      border: 1px solid var(--outline);
    }

    .cl-symbol.start {
      border: 2.5px solid #4caf50;
      outline: 1px solid var(--outline);
      outline-offset: -2.5px;
    }

    .cl-symbol.final {
      border: 2.5px solid #f44336;
      outline: 1px solid var(--outline);
      outline-offset: -2.5px;
    }

    .cl-symbol.dead {
      border-style: dashed;
      opacity: 0.6;
    }

    .cl-divider {
      height: 1px;
      background: var(--outline-variant);
      margin: 0.1rem 0;
    }

    .cl-line {
      width: 18px;
      height: 2px;
      background: var(--outline);
    }

    .cl-line.dashed {
      background: none;
      border-top: 2px dashed var(--primary-container);
    }

    @keyframes fadeScaleIn {
      from {
        opacity: 0;
        transform: scale(0.9) translateY(-4px);
      }

      to {
        opacity: 1;
        transform: scale(1) translateY(0);
      }
    }

    /* Regex canvas display (shown on regex stage, post-generate) */
    #regex-canvas-display {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 1.5rem;
      z-index: 2;
      padding: 2rem;
    }

    .rcd-badge {
      font-size: 0.65rem;
      font-weight: 700;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      color: var(--primary);
      background: rgba(0, 91, 191, 0.08);
      padding: 0.3rem 0.9rem;
      border-radius: var(--radius-full);
    }

    .rcd-regex-wrap {
      background: var(--surface-lowest);
      border-radius: var(--radius-2xl);
      padding: 2rem 3rem;
      box-shadow: var(--float-shadow);
      text-align: center;
      max-width: 600px;
      width: 100%;
    }

    .rcd-label {
      font-size: 0.68rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--outline);
      margin-bottom: 0.7rem;
    }

    .rcd-regex-str {
      font-family: 'JetBrains Mono', monospace;
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.08em;
      word-break: break-all;
      line-height: 1.2;
    }

    .rcd-pills {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem;
      justify-content: center;
      margin-top: 1.2rem;
    }

    .rcd-pill {
      padding: 0.35rem 0.85rem;
      border-radius: var(--radius-full);
      font-size: 0.72rem;
      font-weight: 600;
      font-family: 'JetBrains Mono', monospace;
    }

    .rcd-pill.syms {
      background: rgba(0, 91, 191, 0.1);
      color: var(--primary);
    }

    .rcd-pill.ops {
      background: rgba(124, 58, 237, 0.1);
      color: #7c3aed;
    }

    .rcd-pill.postfix {
      background: rgba(0, 110, 28, 0.1);
      color: var(--secondary);
    }

    .rcd-desc {
      font-size: 0.82rem;
      color: var(--on-surface-variant);
      line-height: 1.6;
      font-style: italic;
      max-width: 480px;
      text-align: center;
    }

    .rcd-arrow-row {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      font-size: 0.8rem;
      color: var(--outline);
    }

    .rcd-step {
      background: var(--surface-lowest);
      border-radius: var(--radius-xl);
      padding: 0.55rem 1.1rem;
      font-family: 'Manrope', sans-serif;
      font-size: 0.78rem;
      font-weight: 700;
      color: var(--on-surface);
      box-shadow: var(--lift-shadow);
    }

    /* ── Right Panel ── */
    #right-panel {
      width: var(--right-width);
      background: var(--surface-low);
      display: flex;
      flex-direction: column;
      overflow: hidden;
      flex-shrink: 0;
    }

    .rp-tabs {
      display: flex;
      background: var(--surface-highest);
      flex-shrink: 0;
    }

    .rp-tab {
      flex: 1;
      padding: 0.65rem 0.2rem;
      font-size: 0.63rem;
      font-weight: 700;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      color: var(--outline);
      cursor: pointer;
      border-bottom: 2.5px solid transparent;
      text-align: center;
      transition: all var(--dur-fast);
    }

    .rp-tab:hover {
      color: var(--on-surface);
    }

    .rp-tab.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
      background: var(--surface-lowest);
    }

    .rp-content {
      flex: 1;
      overflow-y: auto;
      padding: 1rem;
    }

    .rp-pane {
      display: none;
    }

    .rp-pane.active {
      display: block;
    }

    /* Explanation cards */
    .exp-card {
      background: var(--surface-lowest);
      border-radius: var(--radius-xl);
      padding: 1rem;
      margin-bottom: 0.75rem;
      box-shadow: var(--ambient-shadow);
    }

    .exp-step-badge {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 26px;
      height: 26px;
      background: var(--primary);
      border-radius: var(--radius-full);
      font-size: 0.72rem;
      font-weight: 700;
      color: white;
      margin-bottom: 0.5rem;
    }

    .exp-title {
      font-family: 'Manrope', sans-serif;
      font-size: 0.95rem;
      font-weight: 700;
      color: var(--on-surface);
      margin-bottom: 0.35rem;
    }

    .exp-desc {
      font-size: 0.78rem;
      color: var(--on-surface-variant);
      line-height: 1.55;
    }

    .exp-diagram {
      margin: 0.5rem 0;
      padding: 0.5rem 0.7rem;
      background: var(--surface-highest);
      border-radius: var(--radius-md);
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.75rem;
      color: var(--primary);
      font-weight: 500;
    }

    .why-btn {
      display: inline-flex;
      align-items: center;
      gap: 0.3rem;
      background: none;
      border: 1.5px solid var(--outline-variant);
      color: var(--outline);
      font-family: 'Inter', sans-serif;
      font-size: 0.7rem;
      font-weight: 600;
      padding: 0.3rem 0.6rem;
      border-radius: var(--radius-full);
      cursor: pointer;
      margin-top: 0.5rem;
      transition: all var(--dur-fast);
    }

    .why-btn:hover {
      border-color: var(--primary);
      color: var(--primary);
    }

    .why-body {
      margin-top: 0.5rem;
      padding: 0.6rem;
      background: rgba(0, 91, 191, 0.06);
      border-radius: var(--radius-md);
      font-size: 0.73rem;
      color: var(--on-surface-variant);
      line-height: 1.5;
      display: none;
    }

    .why-body.open {
      display: block;
    }

    /* Stack */
    .stack-container {
      background: var(--surface-lowest);
      border-radius: var(--radius-xl);
      padding: 0.8rem;
      box-shadow: var(--ambient-shadow);
      min-height: 120px;
    }

    .stack-top-label {
      font-size: 0.62rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--primary);
      margin-bottom: 0.5rem;
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }

    .stack-top-label::after {
      content: '';
      flex: 1;
      height: 1px;
      background: var(--outline-variant);
      opacity: 0.4;
    }

    .stack-items {
      display: flex;
      flex-direction: column-reverse;
      gap: 0.3rem;
    }

    .stack-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0.45rem 0.7rem;
      background: var(--surface-highest);
      border-radius: var(--radius-md);
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.73rem;
      color: var(--primary);
      font-weight: 600;
      animation: slideUpIn var(--dur-fast) var(--ease-socialite);
    }

    .stack-item .si-label {
      color: var(--outline);
      font-size: 0.62rem;
      font-family: 'Inter', sans-serif;
    }

    @keyframes slideUpIn {
      from {
        opacity: 0;
        transform: translateY(6px);
      }

      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    /* Tables tab */
    .data-table-wrap {
      background: var(--surface-lowest);
      border-radius: var(--radius-xl);
      overflow: hidden;
      box-shadow: var(--ambient-shadow);
      margin-bottom: 0.75rem;
    }

    .dt-header {
      padding: 0.6rem 0.8rem;
      background: var(--surface-high);
      font-size: 0.65rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .data-table {
      width: 100%;
      border-collapse: collapse;
      font-size: 0.72rem;
      font-family: 'JetBrains Mono', monospace;
    }

    .data-table th {
      background: var(--surface-highest);
      color: var(--outline);
      font-size: 0.63rem;
      font-weight: 700;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      padding: 0.4rem 0.6rem;
      text-align: left;
    }

    .data-table td {
      padding: 0.38rem 0.6rem;
      color: var(--on-surface-variant);
    }

    .data-table tr:hover td {
      background: var(--surface-highest);
    }

    .data-table tr.final-r td {
      color: var(--tertiary);
      font-weight: 600;
    }

    /* Simulate tab */
    .sim-section {
      display: flex;
      flex-direction: column;
      gap: 0.6rem;
    }

    .sim-btn {
      width: 100%;
      padding: 0.65rem;
      border-radius: var(--radius-lg);
      border: none;
      font-family: 'Inter', sans-serif;
      font-size: 0.8rem;
      font-weight: 700;
      cursor: pointer;
      transition: all var(--dur-fast) var(--ease-socialite);
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0.4rem;
    }

    .sim-btn.forward {
      background: linear-gradient(135deg, var(--primary), var(--primary-container));
      color: var(--on-primary);
      box-shadow: 0 4px 12px rgba(0, 91, 191, 0.2);
    }

    .sim-btn.forward:hover {
      transform: translateY(-1px);
      box-shadow: 0 6px 18px rgba(0, 91, 191, 0.3);
    }

    .sim-btn.reverse {
      background: var(--surface-lowest);
      color: var(--primary);
      border: 1.5px solid rgba(0, 91, 191, 0.25);
      box-shadow: var(--lift-shadow);
    }

    .sim-btn.reverse:hover {
      background: rgba(0, 91, 191, 0.06);
    }

    .quick-test-row {
      display: flex;
      gap: 0.4rem;
    }

    .quick-test-input {
      flex: 1;
      background: var(--surface-highest);
      border: none;
      border-bottom: 1.5px solid var(--outline-variant);
      border-radius: var(--radius-md) var(--radius-md) 0 0;
      padding: 0.45rem 0.6rem;
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.82rem;
      color: var(--on-surface);
      outline: none;
      transition: border-color var(--dur-fast);
    }

    .quick-test-input:focus {
      border-bottom-color: var(--primary);
    }

    .quick-test-run {
      padding: 0.45rem 0.8rem;
      background: var(--primary);
      color: var(--on-primary);
      border: none;
      border-radius: var(--radius-md);
      font-family: 'Inter', sans-serif;
      font-size: 0.75rem;
      font-weight: 700;
      cursor: pointer;
      transition: all var(--dur-fast);
    }

    .quick-test-run:hover {
      background: #004ea3;
    }

    .quick-result {
      padding: 0.5rem 0.7rem;
      border-radius: var(--radius-md);
      font-size: 0.78rem;
      font-weight: 600;
      display: none;
    }

    .quick-result.accepted {
      background: rgba(0, 110, 28, 0.1);
      color: var(--secondary);
      display: block;
    }

    .quick-result.rejected {
      background: rgba(187, 22, 19, 0.08);
      color: var(--tertiary);
      display: block;
    }

    /* Theory tab */
    .concept-item {
      background: var(--surface-lowest);
      border-radius: var(--radius-xl);
      padding: 0.7rem 0.9rem;
      margin-bottom: 0.5rem;
      cursor: pointer;
      box-shadow: var(--ambient-shadow);
      transition: box-shadow var(--dur-fast);
    }

    .concept-item:hover {
      box-shadow: var(--lift-shadow);
    }

    .concept-title {
      font-family: 'Manrope', sans-serif;
      font-size: 0.82rem;
      font-weight: 700;
      color: var(--on-surface);
      margin-bottom: 0.2rem;
    }

    .concept-def {
      font-size: 0.73rem;
      color: var(--on-surface-variant);
      line-height: 1.45;
      display: none;
      margin-top: 0.4rem;
    }

    .concept-def.open {
      display: block;
    }

    /* ── Simulation Modal ── */
    .modal-overlay {
      position: fixed;
      inset: 0;
      background: rgba(7, 30, 39, 0.35);
      backdrop-filter: blur(6px);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      pointer-events: none;
      transition: opacity var(--dur-normal) var(--ease-socialite);
    }

    .modal-overlay.open {
      opacity: 1;
      pointer-events: all;
    }

    .modal {
      background: var(--surface-lowest);
      border-radius: var(--radius-2xl);
      padding: 1.75rem;
      width: 540px;
      max-width: calc(100vw - 2rem);
      max-height: 88vh;
      overflow-y: auto;
      box-shadow: var(--float-shadow);
      transform: scale(0.96) translateY(10px);
      transition: transform var(--dur-normal) var(--ease-socialite);
      position: relative;
    }

    .modal-overlay.open .modal {
      transform: scale(1) translateY(0);
    }

    .modal-eyebrow {
      font-size: 0.65rem;
      font-weight: 700;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--primary);
      margin-bottom: 0.3rem;
    }

    .modal-title {
      font-family: 'Manrope', sans-serif;
      font-size: 1.3rem;
      font-weight: 800;
      color: var(--on-surface);
      margin-bottom: 1.2rem;
    }

    .modal-close {
      position: absolute;
      top: 1.5rem;
      right: 1.75rem;
      background: var(--surface-highest);
      border: none;
      color: var(--outline);
      width: 30px;
      height: 30px;
      border-radius: 50%;
      font-size: 0.9rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: all var(--dur-fast);
    }

    .modal-close:hover {
      background: var(--surface-high);
      color: var(--on-surface);
    }

    .modal-mode-row {
      display: flex;
      gap: 0.5rem;
      margin-bottom: 1rem;
    }

    .mode-chip {
      padding: 0.35rem 0.9rem;
      background: var(--surface-highest);
      border: none;
      border-radius: var(--radius-full);
      font-family: 'Inter', sans-serif;
      font-size: 0.73rem;
      font-weight: 600;
      color: var(--outline);
      cursor: pointer;
      transition: all var(--dur-fast);
    }

    .mode-chip.active {
      background: rgba(0, 91, 191, 0.12);
      color: var(--primary);
    }

    .modal-input-row {
      display: flex;
      gap: 0.5rem;
      margin-bottom: 0.8rem;
    }

    .modal-input {
      flex: 1;
      background: var(--surface-high);
      border: none;
      border-bottom: 2px solid var(--outline-variant);
      border-radius: var(--radius-md) var(--radius-md) 0 0;
      padding: 0.65rem 0.8rem;
      font-family: 'JetBrains Mono', monospace;
      font-size: 1rem;
      color: var(--on-surface);
      outline: none;
      transition: border-color var(--dur-fast);
      letter-spacing: 0.08em;
    }

    .modal-input:focus {
      border-bottom-color: var(--primary);
      background: var(--surface-lowest);
    }

    .modal-run-btn {
      padding: 0.65rem 1.2rem;
      background: linear-gradient(135deg, var(--primary), var(--primary-container));
      color: var(--on-primary);
      border: none;
      border-radius: var(--radius-lg);
      font-family: 'Inter', sans-serif;
      font-size: 0.8rem;
      font-weight: 700;
      cursor: pointer;
      transition: all var(--dur-fast) var(--ease-socialite);
      white-space: nowrap;
      box-shadow: var(--lift-shadow);
    }

    .modal-run-btn:hover {
      transform: translateY(-1px);
      box-shadow: var(--ambient-shadow);
    }

    .modal-result {
      border-radius: var(--radius-xl);
      padding: 1rem 1.2rem;
      display: none;
      text-align: center;
      margin-bottom: 1rem;
    }

    .modal-result.accepted {
      background: rgba(0, 110, 28, 0.08);
      display: block;
    }

    .modal-result.rejected {
      background: rgba(187, 22, 19, 0.06);
      display: block;
    }

    .result-icon {
      font-size: 2rem;
      display: block;
      margin-bottom: 0.25rem;
    }

    .result-text {
      font-family: 'Manrope', sans-serif;
      font-size: 1rem;
      font-weight: 700;
    }

    .modal-result.accepted .result-text {
      color: var(--secondary);
    }

    .modal-result.rejected .result-text {
      color: var(--tertiary);
    }

    .trace-log-wrap {
      background: var(--surface-high);
      border-radius: var(--radius-lg);
      padding: 0.8rem;
      max-height: 200px;
      overflow-y: auto;
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.75rem;
    }

    .trace-step {
      display: flex;
      align-items: center;
      gap: 0.4rem;
      padding: 0.22rem 0;
      animation: fadeDown var(--dur-fast) var(--ease-socialite);
    }

    @keyframes fadeDown {
      from {
        opacity: 0;
        transform: translateY(-4px);
      }

      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    .t-num {
      color: var(--outline);
      min-width: 20px;
      font-size: 0.63rem;
    }

    .t-from {
      color: var(--primary);
      font-weight: 600;
    }

    .t-arrow,
    .t-paren {
      color: var(--outline);
    }

    .t-via {
      color: #7c3aed;
      font-weight: 600;
    }

    .t-to {
      color: var(--secondary);
      font-weight: 600;
    }

    .t-err {
      color: var(--tertiary);
      font-weight: 600;
    }

    .trace-info-row {
      display: flex;
      gap: 0.5rem;
      margin-top: 0.6rem;
    }

    .trace-badge {
      flex: 1;
      background: var(--surface-highest);
      border-radius: var(--radius-md);
      padding: 0.4rem 0.6rem;
    }

    .tb-label {
      font-size: 0.6rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.06em;
      color: var(--outline);
    }

    .tb-val {
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.78rem;
      font-weight: 700;
      color: var(--on-surface);
      margin-top: 0.1rem;
    }

    .reverse-path {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 0.25rem;
      padding: 0.7rem;
      background: var(--surface-high);
      border-radius: var(--radius-lg);
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.78rem;
      margin-top: 0.6rem;
    }

    .rev-state {
      color: var(--primary);
      background: rgba(0, 91, 191, 0.1);
      padding: 0.2rem 0.45rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }

    .rev-arrow {
      color: var(--outline);
    }

    .rev-sym {
      color: #7c3aed;
      font-size: 0.65rem;
    }

    /* ── Presentation Mode ── */
    #pres-mode {
      position: fixed;
      inset: 0;
      background: var(--surface-lowest);
      z-index: 2000;
      display: none;
      flex-direction: column;
    }

    #pres-mode.open {
      display: flex;
    }

    .pres-top {
      height: 56px;
      background: var(--surface-low);
      display: flex;
      align-items: center;
      padding: 0 2rem;
      justify-content: space-between;
      flex-shrink: 0;
    }

    .pres-brand {
      font-family: 'Manrope', sans-serif;
      font-weight: 800;
      font-size: 1rem;
      color: var(--primary);
    }

    .pres-slide-info {
      font-size: 0.75rem;
      color: var(--outline);
      font-family: 'JetBrains Mono', monospace;
    }

    .pres-exit {
      padding: 0.35rem 0.8rem;
      background: rgba(187, 22, 19, 0.08);
      border: none;
      border-radius: var(--radius-full);
      color: var(--tertiary);
      font-family: 'Inter', sans-serif;
      font-size: 0.75rem;
      font-weight: 600;
      cursor: pointer;
      transition: all var(--dur-fast);
    }

    .pres-exit:hover {
      background: rgba(187, 22, 19, 0.15);
    }

    .pres-body {
      flex: 1;
      display: flex;
      overflow: hidden;
    }

    .pres-canvas {
      flex: 1;
      position: relative;
      background: var(--surface);
    }

    .pres-canvas::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: radial-gradient(circle, var(--outline-variant) 1px, transparent 1px);
      background-size: 28px 28px;
      opacity: 0.3;
    }

    #pres-cy {
      width: 100%;
      height: 100%;
    }

    .pres-info {
      width: 380px;
      padding: 2.5rem 2rem;
      display: flex;
      flex-direction: column;
      gap: 0.8rem;
      overflow-y: auto;
      background: var(--surface-lowest);
    }

    .pres-eyebrow {
      font-size: 0.65rem;
      font-weight: 700;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      color: var(--primary);
    }

    .pres-title {
      font-family: 'Manrope', sans-serif;
      font-size: 1.7rem;
      font-weight: 800;
      color: var(--on-surface);
      line-height: 1.15;
    }

    .pres-desc {
      font-size: 0.86rem;
      color: var(--on-surface-variant);
      line-height: 1.65;
    }

    .pres-diagram-block {
      padding: 0.6rem 0.8rem;
      background: var(--surface-highest);
      border-radius: var(--radius-md);
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.78rem;
      color: var(--primary);
    }

    .pres-footer {
      height: 68px;
      background: var(--surface-highest);
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 1.2rem;
      flex-shrink: 0;
    }

    .pres-nav-btn {
      padding: 0.6rem 1.5rem;
      background: var(--surface-lowest);
      border: none;
      border-radius: var(--radius-full);
      font-family: 'Inter', sans-serif;
      font-size: 0.82rem;
      font-weight: 700;
      color: var(--on-surface-variant);
      cursor: pointer;
      transition: all var(--dur-normal) var(--ease-socialite);
      box-shadow: var(--lift-shadow);
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }

    .pres-nav-btn:hover {
      background: var(--surface-high);
      color: var(--on-surface);
    }

    .pres-nav-btn.primary {
      background: linear-gradient(135deg, var(--primary), var(--primary-container));
      color: var(--on-primary);
    }

    .pres-nav-btn.primary:hover {
      transform: translateY(-1px);
      box-shadow: var(--ambient-shadow);
    }

    .pres-dots {
      display: flex;
      gap: 0.35rem;
    }

    .pres-dot {
      width: 8px;
      height: 8px;
      border-radius: var(--radius-full);
      background: var(--outline-variant);
      transition: all var(--dur-normal) var(--ease-socialite);
      cursor: pointer;
    }

    .pres-dot.done {
      background: var(--secondary);
    }

    .pres-dot.active {
      background: var(--primary);
      width: 22px;
    }

    /* Toast */
    #toast-wrap {
      position: fixed;
      bottom: 1.5rem;
      left: 50%;
      transform: translateX(-50%);
      z-index: 3000;
      display: flex;
      flex-direction: column-reverse;
      gap: 0.4rem;
      pointer-events: none;
    }

    .toast {
      padding: 0.55rem 1rem;
      background: var(--on-surface);
      color: var(--surface);
      border-radius: var(--radius-full);
      font-size: 0.78rem;
      font-weight: 500;
      box-shadow: var(--float-shadow);
      animation: toastIn 0.3s var(--ease-socialite), toastOut 0.3s var(--ease-socialite) 2.5s forwards;
      pointer-events: all;
    }

    @keyframes toastIn {
      from {
        opacity: 0;
        transform: translateY(8px) scale(0.95);
      }

      to {
        opacity: 1;
        transform: translateY(0) scale(1);
      }
    }

    @keyframes toastOut {
      from {
        opacity: 1;
      }

      to {
        opacity: 0;
        transform: translateY(4px);
      }
    }

    .hidden {
      display: none !important;
    }

    .not-ready {
      font-size: 0.75rem;
      color: var(--outline);
      padding: 0.8rem 0;
      font-style: italic;
    }

    /* ══ Thompson Visualizer Module ══ */
    .module-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100vw;
      height: 100vh;
      background: var(--surface);
      z-index: 2000;
      display: none;
      flex-direction: column;
      animation: slideInDown 0.4s var(--ease-socialite);
    }

    .module-overlay.open {
      display: flex;
    }

    .module-header {
      height: 72px;
      padding: 0 2rem;
      border-bottom: 1px solid var(--outline-variant);
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: var(--surface-low);
    }

    .mh-title {
      font-size: 1.1rem;
      font-weight: 800;
      color: var(--primary);
      margin: 0;
    }

    .mh-badge {
      font-size: 0.65rem;
      text-transform: uppercase;
      font-weight: 800;
      letter-spacing: 0.12em;
      color: var(--outline);
      margin-bottom: 2px;
    }

    .mh-input-wrap {
      display: flex;
      background: var(--surface-highest);
      padding: 4px;
      border-radius: var(--radius-xl);
      border: 1.5px solid var(--outline-variant);
      width: 450px;
    }

    .mh-input-wrap input {
      flex: 1;
      background: transparent;
      border: none;
      padding: 0 1rem;
      color: var(--on-surface);
      font-family: 'JetBrains Mono', monospace;
      font-size: 0.85rem;
    }

    .mh-input-wrap input:focus {
      outline: none;
    }

    .tm-run-btn {
      padding: 0.6rem 1.2rem;
      background: var(--primary);
      color: var(--on-primary);
      border: none;
      border-radius: var(--radius-lg);
      font-size: 0.8rem;
      font-weight: 700;
      cursor: pointer;
    }

    .module-close {
      padding: 0.5rem 1rem;
      background: rgba(244, 67, 54, 0.1);
      color: #f44336;
      border: 1.5px solid rgba(244, 67, 54, 0.2);
      border-radius: var(--radius-md);
      font-size: 0.75rem;
      font-weight: 700;
      cursor: pointer;
    }

    .module-body {
      flex: 1;
      display: flex;
      overflow: hidden;
    }

    .tm-sidebar {
      width: 320px;
      padding: 1.5rem;
      overflow-y: auto;
      border-right: 1px solid var(--outline-variant);
      background: var(--surface-low);
    }

    .tm-sidebar.tm-details {
      width: 360px;
      border-right: none;
      border-left: 1px solid var(--outline-variant);
    }

    .tm-main {
      flex: 1;
      display: flex;
      flex-direction: column;
      position: relative;
    }

    .tm-section {
      margin-bottom: 2.5rem;
    }

    .tm-eyebrow {
      font-size: 0.75rem;
      font-weight: 800;
      text-transform: uppercase;
      color: var(--primary);
      margin-bottom: 1rem;
      letter-spacing: 0.08em;
    }

    .tm-text {
      font-size: 0.82rem;
      line-height: 1.6;
      color: var(--on-surface-variant);
    }

    .tm-list {
      padding-left: 1.2rem;
      font-size: 0.8rem;
      color: var(--on-surface-variant);
    }

    .tm-list li {
      margin-bottom: 0.5rem;
    }

    .rule-card {
      padding: 1rem;
      background: var(--surface);
      border: 1px solid var(--outline-variant);
      border-radius: var(--radius-lg);
      margin-bottom: 0.75rem;
      cursor: pointer;
      transition: all 0.2s var(--ease-socialite);
    }

    .rule-card:hover {
      border-color: var(--primary);
      transform: translateX(4px);
      box-shadow: var(--ambient-shadow);
    }

    .rc-label {
      font-size: 0.85rem;
      font-weight: 700;
      margin-bottom: 0.25rem;
    }

    .rc-desc {
      font-size: 0.7rem;
      color: var(--outline);
      line-height: 1.4;
    }

    .tm-canvas-header {
      padding: 1rem 1.5rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      border-bottom: 1px solid var(--outline-variant);
    }

    .tm-stage-badge {
      display: inline-block;
      padding: 0.25rem 0.6rem;
      background: var(--primary-container);
      color: var(--on-primary-container);
      font-size: 0.65rem;
      font-weight: 800;
      border-radius: 4px;
      text-transform: uppercase;
    }

    .tm-active-sub {
      margin-top: 0.35rem;
      font-family: 'JetBrains Mono', monospace;
      font-weight: 700;
      color: var(--on-surface);
    }

    .tm-cy-container {
      flex: 1;
      position: relative;
    }

    #tm-cy {
      width: 100%;
      height: 100%;
    }

    .tm-stack-overlay {
      position: absolute;
      top: 1.5rem;
      right: 1.5rem;
      width: 200px;
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(10px);
      border: 1px solid var(--outline-variant);
      border-radius: var(--radius-lg);
      padding: 1rem;
      box-shadow: var(--float-shadow);
      z-index: 10;
    }

    .tm-stack-title {
      font-size: 0.7rem;
      font-weight: 800;
      text-transform: uppercase;
      color: var(--outline);
      margin-bottom: 0.75rem;
      text-align: center;
    }

    .tm-stack-list {
      display: flex;
      flex-direction: column-reverse;
      gap: 0.5rem;
    }

    .tm-stack-item {
      padding: 0.5rem;
      background: var(--surface-highest);
      border-radius: var(--radius-md);
      font-size: 0.7rem;
      font-weight: 600;
      text-align: center;
      border: 1px solid var(--outline-variant);
      animation: slideInUp 0.3s var(--ease-socialite);
    }

    .tm-stack-empty {
      font-size: 0.7rem;
      color: var(--outline);
      text-align: center;
      padding: 1rem 0;
    }

    .tm-footer {
      padding: 1rem 1.5rem;
      border-top: 1px solid var(--outline-variant);
      background: var(--surface-low);
    }

    .tm-slider {
      width: 150px;
      accent-color: var(--primary);
    }

    .tm-speed-p {
      display: flex;
      align-items: center;
      gap: 1rem;
      font-size: 0.7rem;
      font-weight: 700;
      color: var(--outline);
    }

    .tm-details-card {
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }

    .tm-details-eyebrow {
      font-size: 0.65rem;
      font-weight: 800;
      text-transform: uppercase;
      color: var(--outline);
    }

    .tm-step-title {
      font-size: 1.25rem;
      font-weight: 800;
      margin: 0;
      line-height: 1.25;
    }

    .tm-step-desc {
      font-size: 0.85rem;
      line-height: 1.6;
      color: var(--on-surface-variant);
    }

    .tm-reasoning-box {
      margin-top: 1.5rem;
      padding: 1rem;
      background: var(--surface-higher);
      border-radius: var(--radius-lg);
    }

    .tm-r-header {
      font-size: 0.7rem;
      font-weight: 800;
      margin-bottom: 0.5rem;
      color: var(--primary);
    }

    .tm-step-why {
      font-size: 0.75rem;
      line-height: 1.6;
      color: var(--on-surface-variant);
      font-style: italic;
    }

    .btn-thompson {
      height: 36px;
      padding: 0 1rem;
      background: var(--surface-high);
      border: 1px solid var(--outline-variant);
      border-radius: var(--radius-md);
      color: var(--primary);
      font-family: 'Inter', sans-serif;
      font-size: 0.78rem;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      transition: all 0.2s var(--ease-socialite);
    }

    .btn-thompson:hover {
      background: var(--primary);
      color: var(--on-primary);
      border-color: var(--primary);
      box-shadow: 0 4px 12px rgba(102, 86, 135, 0.2);
    }

    /* Thompson Visualizer */
    #thompson-mode {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--surface);
      z-index: 9999;
      display: none;
      flex-direction: column;
    }

    #thompson-mode.open {
      display: flex;
    }

    .thompson-body {
      flex: 1;
      overflow-y: auto;
      padding: 3rem 2rem;
      max-width: 900px;
      margin: 0 auto;
      width: 100%;
    }

    .thompson-rule {
      margin-bottom: 4rem;
      padding: 2rem;
      background: var(--surface-low);
      border-radius: var(--radius-lg);
      box-shadow: var(--lift-shadow);
    }

    .thompson-rule h2 {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--primary);
      margin: 0 0 1rem 0;
    }

    .thompson-rule p {
      font-size: 1rem;
      line-height: 1.6;
      color: var(--on-surface-variant);
      margin: 0 0 2rem 0;
    }

    .thompson-svg {
      width: 100%;
      height: auto;
      background: var(--surface);
      border-radius: var(--radius-md);
      padding: 1.5rem;
    }

    .thompson-svg text {
      font-family: 'Inter', sans-serif;
      font-weight: 600;
    }