/* ============================================================
   PHYLOGENETIC TREE EVOLUTION — BEASTX-ALIGNED THEME
   ============================================================ */

  :root {
    --bg: #0a0e14;
    --bg-2: #0f1520;
    --surface: #131c2b;
    --surface-2: #182234;
    --line: rgba(255,255,255,0.07);
    --muted: #6b7a94;
    --body: #b0bdd4;
    --head: #e8edf5;
    --white: #f4f7fc;
    --site-blue: #025196;

    --teal: #00c9a7;
    --teal-dim: rgba(0,201,167,0.12);
    --gold: #f0a500;
    --gold-dim: rgba(240,165,0,0.10);
    --rose: #e05a7a;
    --rose-dim: rgba(224,90,122,0.10);
    --sky: #5ca8e8;
    --sky-dim: rgba(92,168,232,0.10);
    --violet: #a57cf0;
    --violet-dim: rgba(165,124,240,0.10);
    --lime: #7ecd4e;
    --lime-dim: rgba(126,205,78,0.10);

    --accent: var(--teal);
    --accent-dim: var(--teal-dim);
    --accent-dark: color-mix(in srgb, var(--teal) 72%, #041814);
    --accent-glow: rgba(0,201,167,0.18);
    --accent-contrast: #031a14;
    --slider-glow: color-mix(in srgb, var(--accent) 32%, transparent);
    --page-glow-a: rgba(0,201,167,0.10);
    --page-glow-b: rgba(92,168,232,0.08);
    --topbar-bg: rgba(10,14,20,0.84);
    --overlay-backdrop: rgba(0,0,0,0.72);
    --shadow-card: 0 22px 46px rgba(0,0,0,0.24);
    --shadow-card-hover: 0 26px 52px rgba(0,0,0,0.28);
    --shadow-panel: 0 18px 30px rgba(0,0,0,0.18);
    --shadow-modal: 0 32px 80px rgba(0,0,0,0.52);
    --surface-highlight: rgba(255,255,255,0.03);
    --link-underline: color-mix(in srgb, var(--text-secondary) 26%, transparent);
    --input-disabled-bg: color-mix(in srgb, var(--white) 4%, var(--surface));
    --success-ink: #bbf7d0;
    --success-border: rgba(74, 222, 128, 0.30);
    --success-surface: rgba(34, 197, 94, 0.14);
    --warning-ink: #fde68a;
    --warning-border: rgba(251, 191, 36, 0.30);
    --warning-surface: rgba(245, 158, 11, 0.14);
    --danger-ink: #fecaca;
    --danger-border: rgba(248, 113, 113, 0.30);
    --danger-surface: rgba(239, 68, 68, 0.16);
    --canvas-bg: transparent;
    --canvas-tree-branch: #54767c;
    --canvas-tree-node: #28474f;
    --canvas-tree-label: #658187;

    --bg-surface: var(--surface);
    --bg-elevated: var(--surface-2);
    --border: var(--line);
    --border-mid: color-mix(in srgb, var(--head) 12%, transparent);
    --text-primary: var(--head);
    --text-secondary: var(--muted);
    --text-muted: color-mix(in srgb, var(--muted) 76%, transparent);
    --red: var(--rose);

    --mono: "DM Mono", "SFMono-Regular", Menlo, monospace;
    --serif: "Playfair Display", Georgia, serif;
    --sans: "DM Sans", "Avenir Next", "Segoe UI", sans-serif;

    --radius-sm: 12px;
    --radius: 14px;
    --radius-lg: 24px;
    --ease: cubic-bezier(.4,0,.2,1);
    color-scheme: dark;
  }

  :root[data-theme="light"] {
    --bg: #f7f7f3;
    --bg-2: #eef0ea;
    --surface: #ffffff;
    --surface-2: #f4f5ef;
    --line: rgba(58, 67, 81, 0.14);
    --muted: #6c7684;
    --body: #4a5461;
    --head: #232c38;
    --white: #232c38;

    --teal: #4b8196;
    --teal-dim: rgba(75,129,150,0.14);
    --gold: #a8833b;
    --gold-dim: rgba(185,133,44,0.12);
    --rose: #a96c78;
    --rose-dim: rgba(183,103,116,0.12);
    --sky: #5d8ea3;
    --sky-dim: rgba(93,142,163,0.12);
    --violet: #7b88a0;
    --violet-dim: rgba(123,136,160,0.12);
    --lime: #738d61;
    --lime-dim: rgba(122,151,80,0.12);

    --accent: var(--teal);
    --accent-dim: var(--teal-dim);
    --accent-dark: color-mix(in srgb, var(--teal) 72%, #dbe3df);
    --accent-glow: rgba(75,129,150,0.16);
    --accent-contrast: #ffffff;
    --slider-glow: color-mix(in srgb, var(--accent) 22%, transparent);
    --page-glow-a: rgba(75,129,150,0.12);
    --page-glow-b: rgba(185,133,44,0.08);
    --topbar-bg: rgba(247,247,243,0.88);
    --overlay-backdrop: rgba(231, 236, 240, 0.72);
    --shadow-card: 0 18px 36px rgba(31, 45, 61, 0.08);
    --shadow-card-hover: 0 22px 44px rgba(31, 45, 61, 0.12);
    --shadow-panel: 0 16px 26px rgba(31, 45, 61, 0.10);
    --shadow-modal: 0 28px 72px rgba(31, 45, 61, 0.18);
    --surface-highlight: rgba(255,255,255,0.55);
    --link-underline: color-mix(in srgb, var(--text-secondary) 34%, transparent);
    --input-disabled-bg: color-mix(in srgb, var(--surface-2) 85%, var(--surface));
    --success-ink: #23693a;
    --success-border: rgba(34, 197, 94, 0.22);
    --success-surface: rgba(34, 197, 94, 0.08);
    --warning-ink: #8a5a13;
    --warning-border: rgba(245, 158, 11, 0.22);
    --warning-surface: rgba(245, 158, 11, 0.08);
    --danger-ink: #9f2d2d;
    --danger-border: rgba(239, 68, 68, 0.22);
    --danger-surface: rgba(239, 68, 68, 0.08);
    --canvas-bg: transparent;
    --canvas-tree-branch: #44696f;
    --canvas-tree-node: #1f4248;
    --canvas-tree-label: #5a767a;

    --bg-surface: var(--surface);
    --bg-elevated: var(--surface-2);
    --border: var(--line);
    --border-mid: color-mix(in srgb, var(--head) 16%, transparent);
    --text-primary: var(--head);
    --text-secondary: var(--muted);
    --text-muted: color-mix(in srgb, var(--muted) 80%, transparent);
    --red: var(--rose);
    color-scheme: light;
  }

  /* ── Reset ─────────────────────────────────────────────── */
  *, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }

  /* ── Base ──────────────────────────────────────────────── */
  body {
    margin: 0;
    background:
      radial-gradient(circle at top right, var(--page-glow-a), transparent 30%),
      radial-gradient(circle at left 20%, var(--page-glow-b), transparent 28%),
      var(--bg);
    color: var(--body);
    font-family: var(--sans);
    font-size: 17px;
    line-height: 1.7;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    max-width: 100%;
  }

  :root[data-embed="1"] body {
    background: transparent;
    min-height: 0;
    overflow-x: clip;
  }

  :root[data-embed="1"],
  :root[data-embed="1"] body {
    height: auto;
  }

  body.has-open-modal {
    overflow: hidden;
  }

  [hidden] {
    display: none !important;
  }

  .page {
    position: relative;
    min-width: 0;
  }

  :root[data-embed="1"] .topbar,
  :root[data-embed="1"] .hero {
    display: none;
  }

  :root[data-embed="1"] .shell {
    width: 100%;
    padding: 0;
  }

  :root[data-embed="1"] .app-workbench {
    padding: 0;
  }

  :root[data-embed="1"] .app-footer {
    margin-bottom: 0;
    padding-bottom: 0.75rem;
  }

  :root[data-embed="1"][data-integrated="1"] .app-footer {
    display: none;
  }

  :root[data-embed="1"] .app-surface {
    padding: 0;
    border-radius: 0;
    box-shadow: none;
    border: 0;
    background: transparent;
  }

  :root[data-embed="1"][data-integrated="1"] .app-workbench,
  :root[data-embed="1"][data-integrated="1"] .app-surface {
    background: transparent;
  }

  :root[data-embed="1"] .page,
  :root[data-embed="1"] .shell,
  :root[data-embed="1"] .section,
  :root[data-embed="1"] .container,
  :root[data-embed="1"] .app-workbench,
  :root[data-embed="1"] .app-surface,
  :root[data-embed="1"] .canvas-wrapper,
  :root[data-embed="1"] .button-group,
  :root[data-embed="1"] .control-panel {
    max-width: 100%;
    min-width: 0;
  }

  :root[data-embed="1"] .canvas-stage {
    display: block;
    width: min(100%, 1000px);
    max-width: 100%;
    min-width: 0;
  }

  :root[data-embed="1"] #canvas {
    width: min(100%, 1000px) !important;
    height: auto !important;
    max-width: 100%;
    aspect-ratio: 1000 / 700;
  }

  :root[data-embed="1"] .button-group {
    width: 100%;
    align-items: end;
  }

  :root[data-embed="1"] .button-group > *,
  :root[data-embed="1"] .control-section {
    min-width: 0;
    max-width: 100%;
  }

  :root[data-embed="1"] .button-group .control-item,
  :root[data-embed="1"] .button-group .control-stack-vertical {
    margin-left: 0 !important;
  }

  :root[data-embed="1"] .button-group .slider-container {
    width: 100%;
    max-width: 100%;
  }

  :root[data-presentation="1"] {
    --toolbar-content-width: 100%;
  }

  :root[data-presentation="1"],
  :root[data-presentation="1"] body {
    width: 100%;
    height: 100%;
    min-height: 100%;
    overflow: hidden;
  }

  :root[data-presentation="1"] body {
    background: transparent;
    font-size: 12px;
    line-height: 1.25;
  }

  :root[data-presentation="1"] .page,
  :root[data-presentation="1"] .app-workbench,
  :root[data-presentation="1"] .app-surface {
    width: 100%;
    height: 100vh;
    max-height: 100vh;
    overflow: hidden;
  }

  :root[data-presentation="1"] .app-surface {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: minmax(0, 4fr) minmax(0, 1fr);
    gap: 0.45rem;
    padding: 0.45rem;
  }

  :root[data-presentation="1"] .canvas-wrapper {
    grid-row: 1;
    grid-column: 1;
    align-items: center;
    height: 100%;
    min-height: 0;
    padding: 0;
    overflow: hidden;
  }

  :root[data-presentation="1"] .canvas-stage {
    display: grid;
    place-items: center;
    width: 100%;
    height: 100%;
    max-width: 100%;
    min-width: 0;
  }

  :root[data-presentation="1"] #canvas {
    width: 100% !important;
    height: 100% !important;
    max-width: 100%;
    max-height: 100%;
    aspect-ratio: 1000 / 700;
    border-radius: 14px;
  }

  :root[data-presentation="1"] .time-slider-container {
    left: 0.4rem;
    height: 100%;
    width: 3rem;
    z-index: 30;
    pointer-events: auto;
  }

  :root[data-presentation="1"] .time-slider-wrapper {
    height: calc(100% - 1rem);
  }

  :root[data-presentation="1"] .time-slider-vertical {
    width: 2rem;
    height: 100%;
    background: transparent;
  }

  :root[data-presentation="1"] .signature,
  :root[data-presentation="1"] .app-footer,
  :root[data-presentation="1"] .custom-ctmc-launcher {
    display: none;
  }

  .presentation-command-toggle {
    display: none;
  }

  :root[data-presentation="1"] .presentation-command-toggle {
    position: absolute;
    top: 0;
    right: 0;
    z-index: 2300;
    display: inline-grid;
    place-items: center;
    width: var(--presentation-command-toggle-size);
    height: var(--presentation-command-toggle-size);
    min-height: 0;
    appearance: none;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
    color: var(--site-blue);
    box-shadow: none;
    cursor: pointer;
    transition: color 0.15s var(--ease);
  }

  :root[data-presentation="1"] .presentation-command-toggle:hover {
    color: color-mix(in srgb, var(--site-blue) 82%, var(--sky));
    transform: none;
  }

  :root[data-presentation="1"] .presentation-command-toggle:focus-visible {
    outline: 1.5px solid var(--site-blue);
    outline-offset: 0.08rem;
  }

  :root[data-presentation="1"] .presentation-command-toggle-mark {
    display: block;
    width: 0.52rem;
    height: 0.52rem;
  }

  :root[data-presentation="1"] .presentation-command-toggle-mark svg {
    display: block;
    width: 100%;
    height: 100%;
    overflow: visible;
  }

  :root[data-presentation="1"] .presentation-command-toggle-mark path {
    fill: none;
    stroke: currentColor;
    stroke-width: 3.8;
    stroke-linecap: round;
    stroke-linejoin: round;
  }

  :root[data-embed="1"]:not([data-presentation="1"]) .button-group {
    --toolbar-control-height: clamp(32px, 4.5vw, 38px);
    --toolbar-tree-seed-control-height: calc(var(--toolbar-control-height) * 0.78);
    --history-control-height: clamp(24px, 3.6vw, 30px);
    --toolbar-label-height: clamp(0.62rem, 1.4vw, 0.82rem);
    --toolbar-field-gap: clamp(0.08rem, 0.7vw, 0.16rem);
    --toolbar-radius: 10px;
    --toolbar-tree-seed-gap: clamp(0.22rem, 1.1vw, 0.42rem);
    --history-font-size: clamp(0.5rem, 1.3vw, 0.64rem);
    --toolbar-speed-slider-width: clamp(7.2rem, 24vw, 10rem);
    --toolbar-seed-width: clamp(42px, 5vw, 54px);
    --toolbar-button-gap: clamp(0.18rem, 0.7vw, 0.28rem);
    --toolbar-button-padding-inline: clamp(0.48rem, 1.25vw, 0.72rem);
    --toolbar-button-font-size: clamp(0.62rem, 1.45vw, 0.78rem);
    --toolbar-icon-size: 1em;
    --toolbar-label-font-size: clamp(0.56rem, 1.25vw, 0.7rem);
    --toolbar-number-font-size: clamp(0.62rem, 1.35vw, 0.76rem);
    --toolbar-slider-value-font-size: clamp(0.58rem, 1.25vw, 0.72rem);
    --toolbar-checkbox-size: clamp(0.66rem, 1.45vw, 0.82rem);
    --toolbar-mode-gap: clamp(0.16rem, 0.7vw, 0.28rem);
    --toolbar-segment-padding-inline: clamp(0.28rem, 0.8vw, 0.48rem);
  }

  :root[data-presentation="1"][data-commands-hidden] .app-surface {
    grid-template-rows: minmax(0, 1fr);
  }

  :root[data-presentation="1"][data-commands-hidden] .control-panel,
  :root[data-presentation="1"][data-commands-hidden] .custom-ctmc-panel-row {
    display: none;
  }

  :root[data-presentation="1"][data-commands-hidden] .button-group {
    position: fixed;
    right: 0.45rem;
    bottom: 0.45rem;
    z-index: 2300;
    display: block;
    width: var(--presentation-command-toggle-size);
    height: var(--presentation-command-toggle-size);
    margin: 0;
    padding: 0;
    overflow: visible;
  }

  :root[data-presentation="1"][data-commands-hidden] .button-group > :not(.presentation-command-toggle) {
    display: none;
  }

  :root[data-presentation="1"][data-commands-hidden] .presentation-command-toggle {
    position: relative;
    inset: auto;
  }

  :root[data-presentation="1"] .button-group {
    --presentation-command-toggle-size: 0.52rem;
    --toolbar-cluster-gap: clamp(2mm, 1vw, 5mm);
    --toolbar-control-height: 1.22rem;
    --toolbar-tree-seed-control-height: calc(var(--toolbar-control-height) * 0.75);
    --history-control-height: 0.92rem;
    --toolbar-label-height: 0.48rem;
    --toolbar-field-gap: 0.06rem;
    --toolbar-gap: var(--toolbar-cluster-gap);
    --toolbar-radius: 7px;
    --toolbar-tree-seed-gap: 0.18rem;
    --history-font-size: 0.46rem;
    --toolbar-edge-reserve: calc(var(--presentation-command-toggle-size) + 0.18rem);
    --toolbar-speed-slider-width: 8.8rem;
    --toolbar-seed-width: 48px;
    --toolbar-tree-size-width: var(--toolbar-seed-width);
    --toolbar-speed-value-width: 1.35rem;
    --toolbar-button-gap: 0.22rem;
    --toolbar-button-padding-inline: 0.46rem;
    --toolbar-button-font-size: 0.58rem;
    --toolbar-icon-size: 1em;
    --toolbar-label-font-size: 0.5rem;
    --toolbar-number-font-size: 0.55rem;
    --toolbar-slider-value-font-size: 0.5rem;
    --toolbar-checkbox-size: 0.55rem;
    --toolbar-mode-gap: 0.18rem;
    --toolbar-segment-padding-inline: 0.28rem;
    grid-row: 2;
    grid-column: 1;
    align-self: start;
    display: grid;
    grid-template-columns: max-content max-content max-content max-content max-content;
    justify-content: center;
    gap: var(--toolbar-gap);
    height: 1.86rem;
    min-height: 0;
    margin: 0;
    overflow: hidden;
    padding: 0 var(--toolbar-edge-reserve);
    position: relative;
    width: 100%;
  }

  :root[data-presentation="1"] .button-group button:not(.segmented-btn):not(.presentation-command-toggle) {
    height: var(--toolbar-control-height);
    min-height: 0;
    border-radius: var(--toolbar-radius);
    padding: 0 var(--toolbar-button-padding-inline);
    font-size: var(--toolbar-button-font-size);
    line-height: 1;
  }

  :root[data-presentation="1"] #numTipsSelect,
  :root[data-presentation="1"] #seedInput {
    min-height: 0;
    border-radius: 7px;
    font-size: 0.55rem;
    font-weight: 550;
    line-height: 1;
  }

  :root[data-presentation="1"] .toolbar-button {
    gap: 0.22rem;
    padding-inline: 0.46rem;
  }

  :root[data-presentation="1"] .toolbar-button-icon {
    font-size: 1em;
  }

  :root[data-presentation="1"] #playBtn,
  :root[data-presentation="1"] #resetBtn {
    flex: 0 0 auto;
  }

  :root[data-presentation="1"] .icon-button {
    width: var(--toolbar-control-height);
    height: var(--toolbar-control-height);
    padding: 0;
  }

  :root[data-presentation="1"] .button-group label,
  :root[data-presentation="1"] .control-item label,
  :root[data-presentation="1"] .control-item-inline label {
    font-size: 0.5rem;
    line-height: var(--toolbar-label-height);
  }

  :root[data-presentation="1"] .toolbar-field label,
  :root[data-presentation="1"] .toolbar-section-label {
    min-height: var(--toolbar-label-height);
    line-height: var(--toolbar-label-height);
  }

  :root[data-presentation="1"] .toolbar-section,
  :root[data-presentation="1"] .button-group .control-item,
  :root[data-presentation="1"] .track-branches {
    gap: var(--toolbar-field-gap);
    margin: 0 !important;
    padding-left: 0;
  }

  :root[data-presentation="1"] .toolbar-actions {
    align-self: center;
    gap: 0.18rem;
  }

  :root[data-presentation="1"] .toolbar-tree-seed {
    grid-template-columns: var(--toolbar-tree-size-width) var(--toolbar-seed-width);
    gap: var(--toolbar-tree-seed-gap);
  }

  :root[data-presentation="1"] .toolbar-modes {
    --toolbar-modes-y-offset: 0.28rem;
    align-self: center;
    padding: 0;
    border-inline: 0;
    transform: translateY(var(--toolbar-modes-y-offset));
  }

  :root[data-presentation="1"] .button-group .slider-container {
    width: max-content;
  }

  :root[data-presentation="1"] .slider-value {
    min-width: 1.35rem;
    font-size: 0.5rem;
  }

  :root[data-presentation="1"] #numTipsSelect {
    padding-inline: 8px;
  }

  :root[data-presentation="1"] #seedInput {
    padding-inline: 8px;
  }

  :root[data-presentation="1"] .segmented {
    height: var(--history-control-height);
  }

  :root[data-presentation="1"] .button-group .segmented-btn {
    height: 100%;
    min-width: 0;
    padding: 0 var(--toolbar-segment-padding-inline);
    font-size: var(--history-font-size);
  }

  :root[data-presentation="1"] .control-panel {
    grid-row: 2;
    grid-column: 1;
    align-self: end;
    justify-self: center;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.38rem;
    width: min(100%, var(--toolbar-content-width));
    max-width: var(--toolbar-content-width);
    height: calc(100% - 2.35rem);
    min-height: 0;
    margin: 0;
    overflow: hidden;
  }

  :root[data-presentation="1"] .control-section {
    height: 100%;
    min-height: 0;
    overflow: hidden;
    border-radius: 10px;
    padding: 0.38rem 0.48rem;
    box-shadow: none;
  }

  :root[data-presentation="1"] .control-section:hover {
    transform: none;
    box-shadow: none;
  }

  :root[data-presentation="1"] .control-section-header {
    gap: 0.25rem;
    margin-bottom: 0.28rem;
    padding-bottom: 0.22rem;
    font-size: 0.52rem;
    line-height: 1;
  }

  :root[data-presentation="1"] .control-section-header::before {
    width: 2px;
    height: 10px;
  }

  :root[data-presentation="1"] .control-section-header input[type="checkbox"],
  :root[data-presentation="1"] .control-item-inline input[type="checkbox"] {
    transform: scale(0.85);
  }

  :root[data-presentation="1"] .mode-checkbox input[type="checkbox"] {
    width: var(--toolbar-checkbox-size);
    height: var(--toolbar-checkbox-size);
    flex-basis: var(--toolbar-checkbox-size);
    transform: none;
  }

  :root[data-presentation="1"] .mode-checkbox {
    gap: var(--toolbar-mode-gap);
  }

  :root[data-presentation="1"] .panel-visibility-btn {
    --panel-toggle-size: 0.87rem;
    --panel-toggle-icon-size: calc(var(--panel-toggle-size) * 0.68);
  }

  :root[data-presentation="1"] .help-button {
    --help-button-size: 1rem;
    font-size: 0.58rem;
  }

  :root[data-presentation="1"] .control-group,
  :root[data-presentation="1"] .child-controls {
    gap: 0.22rem;
  }

  :root[data-presentation="1"] .child-controls {
    margin-left: 0;
    padding-left: 0.35rem;
    border-left-width: 1px;
  }

  :root[data-presentation="1"] .control-item {
    gap: 0.12rem;
  }

  :root[data-presentation="1"] .control-item-inline {
    gap: 0.22rem;
  }

  :root[data-presentation="1"] .checkbox-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.14rem 0.35rem;
  }

  .shell {
    width: min(1180px, 100%);
    margin: 0 auto;
    padding: 0 28px;
  }

  .container {
    width: 100%;
    max-width: none;
  }

  /* ── Website Shell ─────────────────────────────────────── */
  .topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    background: var(--topbar-bg);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--line);
  }

  .topbar-inner {
    width: min(1180px, 100%);
    margin: 0 auto;
    padding: 14px 28px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
  }

  .brand {
    font-family: var(--serif);
    color: var(--white);
    font-size: 24px;
    font-weight: 900;
    letter-spacing: -0.03em;
    text-decoration: none;
  }

  .brand span,
  .accent {
    color: var(--accent);
  }

  .topnav {
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
    color: var(--muted);
    font-size: 14px;
    align-items: center;
  }

  .topnav a {
    color: inherit;
    text-decoration: none;
    transition: color .2s var(--ease);
  }

  .topnav a:hover {
    color: var(--head);
  }

  .topnav-sep {
    opacity: 0.5;
  }

  .theme-toggle {
    min-width: 76px;
    padding: 7px 12px;
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 700;
    line-height: 1;
    letter-spacing: 0.02em;
    color: var(--text-primary);
    background: color-mix(in srgb, var(--white) 4%, var(--surface-2));
    border: 1px solid var(--line);
    box-shadow: none;
  }

  .theme-toggle:hover {
    transform: none;
    background: color-mix(in srgb, var(--accent) 14%, var(--surface-2));
    border-color: color-mix(in srgb, var(--accent) 28%, transparent);
  }

  .theme-toggle:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
  }

  .hero {
    padding: 72px 0 32px;
  }

  .eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    border-radius: 999px;
    background: var(--accent-dim);
    border: 1px solid color-mix(in srgb, var(--accent) 28%, transparent);
    color: var(--accent);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
  }

  .eyebrow::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent);
  }

  .hero-grid {
    margin-top: 24px;
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(300px, 430px);
    gap: 28px;
    align-items: start;
  }

  .hero-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 24px;
    box-shadow: var(--shadow-card);
    padding: 22px 24px;
  }

  .hero-card h2 {
    margin: 0 0 10px;
    color: var(--head);
    font-size: 18px;
    letter-spacing: -.02em;
  }

  .hero-card p {
    margin: 0;
    color: var(--muted);
    font-size: 15px;
    line-height: 1.65;
  }

  .app-hero-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 14px;
  }

  .chip {
    display: inline-flex;
    padding: 5px 10px;
    border-radius: 999px;
    border: 1px solid color-mix(in srgb, var(--accent) 24%, transparent);
    background: color-mix(in srgb, var(--accent) 12%, transparent);
    color: var(--accent);
    font-family: var(--mono);
    font-size: 12px;
  }

  .app-workbench {
    padding: 8px 0 72px;
    background: transparent;
  }

  .app-surface {
    background: transparent;
    border: 1px solid transparent;
    border-radius: 28px;
    box-shadow: none;
    padding: 28px 24px 24px;
  }

  /* ── Header ────────────────────────────────────────────── */
  h1 {
    margin: 0 0 18px;
    font-family: var(--serif);
    font-size: clamp(44px, 6vw, 84px);
    line-height: 1.05;
    color: var(--white);
    letter-spacing: -.05em;
  }

  .subtitle {
    max-width: 700px;
    margin: 0;
    color: var(--body);
    font-size: 19px;
  }

  /* ── Canvas wrapper ───────────────────────────────────── */
  .canvas-wrapper {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
  }

  .canvas-stage {
    position: relative;
    display: inline-block;
  }

  #canvas {
    display: block;
    background: var(--canvas-bg);
    border: 1px solid transparent;
    border-radius: var(--radius-lg);
    box-shadow: none;
  }

  /* ── Footer ────────────────────────────────────────────── */
  .app-footer {
    margin: 20px auto 0;
    width: min(920px, 100%);
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
    color: var(--muted);
    font-size: 0.82rem;
  }

  .app-footer .sep { opacity: 0.5; }

  .app-footer a {
    color: var(--text-secondary);
    text-decoration: none;
    border-bottom: 1px solid var(--link-underline);
    transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
  }

  .app-footer a:hover {
    color: var(--accent);
    border-bottom-color: var(--accent);
  }

  /* ── Signature ─────────────────────────────────────────── */
  .signature {
    position: absolute;
    bottom: 15px;
    right: 20px;
    font-size: 0.68rem;
    color: color-mix(in srgb, var(--muted) 82%, transparent);
    font-weight: 500;
    pointer-events: none;
    z-index: 10;
    max-width: 150px;
    text-align: right;
    line-height: 1.2;
  }

  /* ── Time slider ───────────────────────────────────────── */
  .time-slider-container {
    position: absolute;
    left: -80px;
    top: 0;
    height: 700px;
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 60px;
  }

  .time-slider-container.active { display: flex; }

  .time-slider-wrapper {
    position: relative;
    height: 600px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
  }

  .time-label {
    font-size: 11px;
    color: var(--text-secondary);
    font-weight: 600;
    margin-bottom: 4px;
    text-align: center;
    writing-mode: horizontal-tb;
    letter-spacing: 0.04em;
    text-transform: uppercase;
  }

  .time-slider-vertical {
    -webkit-appearance: slider-vertical;
    appearance: slider-vertical;
    writing-mode: bt-lr;
    transform: rotate(180deg);
    transform-origin: center;
    width: 8px;
    height: 500px;
    background: var(--bg-elevated);
    border-radius: 4px;
    outline: none;
    cursor: pointer;
  }

  .time-slider-vertical::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: var(--red);
    cursor: pointer;
    box-shadow: 0 1px 5px color-mix(in srgb, var(--red) 34%, transparent);
  }

  .time-slider-vertical::-moz-range-thumb {
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: var(--red);
    cursor: pointer;
    border: none;
    box-shadow: 0 1px 5px color-mix(in srgb, var(--red) 34%, transparent);
  }

  /* ── Buttons (base) ─────────────────────────────────────── */
  button {
    font-family: inherit;
    background: color-mix(in srgb, var(--white) 4%, var(--surface-2));
    color: var(--text-primary);
    border: 1px solid var(--line);
    padding: 10px 22px;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.92rem;
    font-weight: 600;
    transition: background 0.18s var(--ease), border-color 0.18s var(--ease),
                box-shadow 0.18s var(--ease), transform 0.15s var(--ease);
    box-shadow: none;
  }

  button:hover {
    background: color-mix(in srgb, var(--accent) 12%, var(--surface-2));
    border-color: color-mix(in srgb, var(--accent) 28%, transparent);
    box-shadow: none;
    transform: translateY(-1px);
  }

  button:active { transform: translateY(0); }

  #playBtn, #resetBtn {
    background: color-mix(in srgb, var(--accent) 18%, var(--surface-2));
    border-color: color-mix(in srgb, var(--accent) 40%, transparent);
    color: var(--head);
    box-shadow: var(--shadow-panel);
  }

  #playBtn:hover, #resetBtn:hover {
    background: color-mix(in srgb, var(--accent) 24%, var(--surface-2));
    border-color: color-mix(in srgb, var(--accent) 50%, transparent);
    box-shadow: var(--shadow-card);
  }

  /* ── Icon button ────────────────────────────────────────── */
  .icon-button {
    width: 40px;
    height: 40px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    border-radius: var(--radius);
  }

  /* ── Button group ───────────────────────────────────────── */
  .button-group {
    --toolbar-cluster-gap: clamp(2mm, 1vw, 5mm);
    --toolbar-control-height: 42px;
    --toolbar-tree-seed-control-height: calc(var(--toolbar-control-height) * 0.75);
    --history-control-height: 32px;
    --toolbar-label-height: 1rem;
    --toolbar-field-gap: 0.22rem;
    --toolbar-gap: var(--toolbar-cluster-gap);
    --toolbar-radius: 14px;
    --toolbar-tree-seed-gap: 0.55rem;
    --history-font-size: 0.72rem;
    --toolbar-speed-slider-width: 180px;
    --toolbar-seed-width: clamp(36px, 3.1vw, 48px);
    --toolbar-tree-size-width: var(--toolbar-seed-width);
    --toolbar-speed-value-width: 42px;
    --toolbar-button-gap: clamp(0.22rem, 0.8vw, 0.38rem);
    --toolbar-button-padding-inline: clamp(0.62rem, 1.6vw, 1rem);
    --toolbar-button-font-size: clamp(0.72rem, 1.45vw, 0.92rem);
    --toolbar-icon-size: 1.08em;
    --toolbar-label-font-size: clamp(0.68rem, 1.25vw, 0.82rem);
    --toolbar-number-font-size: clamp(0.72rem, 1.35vw, 0.9rem);
    --toolbar-slider-value-font-size: clamp(0.68rem, 1.2vw, 0.85rem);
    --toolbar-checkbox-size: clamp(0.72rem, 1.4vw, 1rem);
    --toolbar-mode-gap: 0.42rem;
    --toolbar-segment-padding-inline: clamp(0.35rem, 1vw, 0.65rem);
    display: grid;
    grid-template-columns: max-content max-content max-content max-content max-content;
    gap: var(--toolbar-gap);
    justify-content: center;
    align-items: end;
    margin-top: 0.95rem;
    margin-bottom: 0;
    width: 100%;
  }

  .button-group button:not(.segmented-btn):not(.presentation-command-toggle) {
    height: var(--toolbar-control-height);
    min-height: 0;
    border-radius: var(--toolbar-radius);
    padding: 0 var(--toolbar-button-padding-inline);
    font-size: var(--toolbar-button-font-size);
    line-height: 1;
  }

  .toolbar-section {
    min-width: 0;
    align-self: end;
  }

  .toolbar-actions {
    display: flex;
    align-self: center;
    align-items: center;
    gap: 0.45rem;
    height: var(--toolbar-control-height);
  }

  .toolbar-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--toolbar-button-gap);
    height: var(--toolbar-control-height);
    min-height: var(--toolbar-control-height);
    padding: 0 var(--toolbar-button-padding-inline);
    border-radius: var(--toolbar-radius);
    font-size: var(--toolbar-button-font-size);
    white-space: nowrap;
    line-height: 1;
  }

  .toolbar-button-icon,
  .toolbar-button-label {
    display: inline-grid;
    place-items: center;
    line-height: 1;
  }

  .toolbar-button-icon {
    font-size: var(--toolbar-icon-size);
    transform: translateY(0.01em);
  }

  .toolbar-button-label {
    transform: translateY(-0.01em);
  }

  .toolbar-actions .icon-button {
    width: var(--toolbar-control-height);
    height: var(--toolbar-control-height);
    flex: 0 0 var(--toolbar-control-height);
    gap: 0;
    padding-inline: 0;
  }

  .button-group button:hover,
  .button-group button:active {
    transform: none;
  }

  .toolbar-tree-seed {
    display: grid;
    grid-template-columns: var(--toolbar-tree-size-width) var(--toolbar-seed-width);
    gap: var(--toolbar-tree-seed-gap);
    align-items: end;
    min-width: 0;
  }

  .toolbar-field {
    display: grid;
    grid-template-rows: var(--toolbar-label-height) var(--toolbar-control-height);
    gap: var(--toolbar-field-gap);
    min-width: 0;
  }

  .toolbar-modes {
    display: grid;
    grid-template-rows: repeat(2, minmax(0, 1fr));
    align-self: center;
    height: var(--toolbar-control-height);
    gap: 0.12rem;
    padding: 0;
    border-inline: 0;
    min-width: 0;
  }

  .button-group label {
    color: var(--text-secondary);
    font-size: var(--toolbar-label-font-size);
    font-weight: 500;
    line-height: var(--toolbar-label-height);
  }

  .toolbar-field label,
  .toolbar-section-label {
    display: flex;
    align-items: center;
    min-height: var(--toolbar-label-height);
    margin: 0;
    white-space: nowrap;
  }

  /* ── Select / number inputs ─────────────────────────────── */
  #numTipsSelect,
  #seedInput {
    width: 100%;
    height: var(--toolbar-tree-seed-control-height);
    min-width: 0;
    align-self: center;
    padding: 0 8px;
    border: 1px solid #e6e6e6;
    border-radius: 7px;
    background: #fff;
    color: #2c3e50;
    font-family: "SFMono-Regular", "JetBrains Mono", Consolas, monospace;
    font-weight: 600;
    font-size: var(--toolbar-number-font-size);
    cursor: pointer;
    font-variant-numeric: tabular-nums;
    transition: border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
  }

  #numTipsSelect {
    appearance: none;
    -webkit-appearance: none;
  }

  .toolbar-field-speed {
    width: calc(var(--toolbar-speed-slider-width) + var(--toolbar-speed-value-width) + 0.55rem);
  }

  .toolbar-field-speed .slider-container {
    width: max-content;
  }

  .toolbar-field-speed .slider-container input[type="range"] {
    flex: 0 0 var(--toolbar-speed-slider-width);
    width: var(--toolbar-speed-slider-width);
  }

  .toolbar-field-tree-size,
  .toolbar-field-tree-size #numTipsSelect {
    width: var(--toolbar-tree-size-width);
  }

  .toolbar-field-seed,
  .toolbar-field-seed #seedInput {
    width: var(--toolbar-seed-width);
  }

  #numTipsSelect:hover, #numTipsSelect:focus,
  #seedInput:hover,     #seedInput:focus {
    border-color: color-mix(in srgb, var(--accent) 45%, transparent);
    box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 28%, transparent);
    outline: none;
  }

  /* ── control-item ───────────────────────────────────────── */
  .control-item {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
  }

  .control-item label {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: var(--panel-label-font-size, var(--toolbar-label-font-size, 0.88rem));
    line-height: var(--panel-label-line-height, 1.2);
  }

  .control-item.toolbar-field {
    display: grid;
    grid-template-rows: var(--toolbar-label-height) var(--toolbar-control-height);
    gap: var(--toolbar-field-gap);
    min-width: 0;
  }

  .button-group .control-item label {
    font-size: var(--toolbar-label-font-size, 0.82rem);
    line-height: var(--toolbar-label-height);
  }

  /* ── control-stack-vertical ─────────────────────────────── */
  .control-stack-vertical {
    display: flex;
    flex-direction: column;
    gap: 5px;
    margin-left: 4px;
    padding-left: 12px;
    border-left: 2px solid var(--border-mid);
  }

  /* ── Segmented control ──────────────────────────────────── */
  .track-branches {
    display: grid;
    grid-template-rows: var(--toolbar-label-height) var(--toolbar-control-height);
    gap: var(--toolbar-field-gap);
    align-items: start;
    justify-content: stretch;
    margin-top: 0;
    min-width: 0;
  }

  .segmented {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-self: center;
    align-items: center;
    height: var(--history-control-height);
    min-width: 0;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: color-mix(in srgb, var(--white) 2%, var(--surface-2));
    overflow: hidden;
    box-shadow: none;
  }

  .segmented-btn {
    appearance: none;
    border: none;
    background: transparent;
    width: 100%;
    height: 100%;
    min-width: 0;
    padding: 0 var(--toolbar-segment-padding-inline, 0.65rem);
    border-radius: 0;
    font-family: inherit;
    font-size: var(--history-font-size);
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.15s var(--ease), color 0.15s var(--ease);
  }

  button.segmented-btn {
    border-block: 0;
    border-inline: 1px solid transparent;
  }

  .segmented-btn + .segmented-btn {
    border-left-color: var(--border);
  }

  .segmented-btn:not(:last-child) {
    border-right-color: var(--border);
  }

  .segmented-btn:hover {
    background: var(--bg-surface);
    color: var(--text-primary);
  }

  .segmented-btn.active,
  .segmented-btn[aria-pressed="true"] {
    background: color-mix(in srgb, var(--accent) 22%, var(--surface-2));
    color: var(--head);
  }

  .segmented-btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
  }

  /* ── Sliders ────────────────────────────────────────────── */
  .slider-container {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    width: 100%;
    height: var(--toolbar-control-height);
    min-width: 0;
  }

  .slider-container input[type="range"] {
    flex: 1;
    height: 5px;
    border-radius: 3px;
    background: var(--bg-elevated);
    outline: none;
    -webkit-appearance: none;
    border: 1px solid var(--border-mid);
  }

  .slider-container input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    box-shadow: 0 0 0 1.5px var(--slider-glow);
    transition: box-shadow 0.18s var(--ease), transform 0.15s var(--ease);
  }

  .slider-container input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.08);
    box-shadow: 0 0 0 3px var(--accent-glow);
  }

  .slider-container input[type="range"]::-moz-range-thumb {
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: none;
    box-shadow: 0 0 0 1.5px var(--slider-glow);
  }

  .slider-value {
    min-width: var(--toolbar-speed-value-width, 42px);
    text-align: right;
    font-weight: 600;
    color: var(--accent);
    font-family: "SFMono-Regular", "JetBrains Mono", Consolas, monospace;
    font-size: var(--toolbar-slider-value-font-size, 0.85rem);
  }

  .control-panel .slider-value,
  .custom-ctmc-panel-row .slider-value {
    min-width: var(--panel-slider-value-width, 2.25rem);
    font-size: var(--panel-slider-value-font-size, var(--panel-label-font-size, 0.82rem));
    line-height: var(--panel-label-line-height, 1.2);
  }

  /* ── Settings modal ─────────────────────────────────────── */
  .settings-modal[hidden] {
    display: none !important;
  }

  .settings-modal {
    position: fixed;
    inset: 0;
    z-index: 2100;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 28px 24px;
    background: var(--overlay-backdrop);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
  }

  .settings-dialog {
    width: min(1040px, 100%);
    max-height: min(88vh, 960px);
    overflow-y: auto;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: var(--surface);
    padding: 30px;
    box-shadow: var(--shadow-modal);
  }

  .settings-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 20px;
  }

  .settings-heading {
    display: grid;
    gap: 0.5rem;
  }

  .settings-eyebrow {
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
  }

  .settings-heading h2 {
    margin: 0;
    color: var(--text-primary);
    font-size: clamp(1.6rem, 1.8vw, 2.1rem);
    line-height: 1.1;
    letter-spacing: -0.03em;
  }

  .settings-heading p {
    margin: 0;
    max-width: 720px;
    color: var(--text-secondary);
    font-size: 0.94rem;
    line-height: 1.65;
  }

  .settings-title {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 0.82rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
  }

  .settings-section-header {
    display: grid;
    gap: 0.45rem;
    margin-bottom: 14px;
  }

  .settings-section-header p {
    margin: 0;
    max-width: 760px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
  }

  .settings-section-header-compact {
    margin-bottom: 12px;
  }

  .settings-divider {
    border: none;
    border-top: 1px solid var(--border);
    margin: 18px 0;
  }

  .settings-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
  }

  @media (max-width: 980px) {
    .settings-grid { grid-template-columns: 1fr; }
  }

  .settings-group {
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 14px;
    background: color-mix(in srgb, var(--surface-2) 80%, var(--surface));
    box-shadow: inset 0 1px 0 var(--surface-highlight);
  }

  .settings-group-title {
    font-weight: 700;
    font-size: 0.78rem;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 10px;
  }

  .settings-row {
    display: grid;
    grid-template-columns: 18px 1fr 60px;
    align-items: center;
    gap: 10px;
    margin: 8px 0;
  }

  .settings-row label {
    font-family: "SFMono-Regular", "JetBrains Mono", Consolas, monospace;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 700;
  }

  .settings-row input[type="range"] {
    width: 100%;
    height: 4px;
    border-radius: 2px;
    background: var(--bg);
    outline: none;
    -webkit-appearance: none;
    border: 1px solid var(--border-mid);
  }

  .settings-row input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
  }

  .settings-row input[type="range"]::-moz-range-thumb {
    width: 9px;
    height: 9px;
    border: 0;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
  }

  .settings-actions {
    margin-top: 18px;
    display: flex;
    justify-content: flex-end;
  }

  .settings-close-button {
    position: static;
    flex-shrink: 0;
    margin-left: auto;
  }

  /* ── Secondary button ───────────────────────────────────── */
  .secondary-button {
    background: transparent;
    border: 1px solid var(--line);
    color: var(--text-secondary);
    padding: 8px 16px;
    font-size: 0.88rem;
    box-shadow: none;
  }

  .secondary-button:hover {
    border-color: color-mix(in srgb, var(--accent) 30%, transparent);
    color: var(--text-primary);
    background: color-mix(in srgb, var(--accent) 10%, var(--surface-2));
    box-shadow: none;
    transform: none;
  }

  /* ── Control panel grid ─────────────────────────────────── */
  .control-panel {
    --panel-label-font-size: 0.82rem;
    --panel-label-line-height: 1.2;
    --panel-slider-value-font-size: 0.82rem;
    --panel-slider-value-width: 2.25rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.35rem;
    margin-top: 1.6rem;
  }

  .custom-ctmc-launcher {
    margin-top: 1.15rem;
    display: none;
    justify-content: flex-start;
  }

  .custom-ctmc-panel-row {
    margin-top: 1rem;
    display: flex;
    justify-content: flex-start;
  }

  .custom-ctmc-panel-row > .control-section {
    width: min(100%, 380px);
  }

  .custom-ctmc-launcher-btn {
    min-height: 46px;
    padding-inline: 22px;
    border-style: dashed;
    background: color-mix(in srgb, var(--accent) 8%, var(--surface-2));
  }

  .control-section {
    position: relative;
    overflow: hidden;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 24px;
    padding: 1.25rem;
    box-shadow: var(--shadow-card);
    transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
  }

  .control-section::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at top right, color-mix(in srgb, var(--accent) 12%, transparent), transparent 42%);
    opacity: 0;
    transition: opacity 0.2s var(--ease);
    pointer-events: none;
  }

  .control-section:hover {
    border-color: color-mix(in srgb, var(--accent) 38%, var(--line));
    transform: translateY(-2px);
    box-shadow: var(--shadow-card-hover);
  }

  .control-section:hover::after {
    opacity: 1;
  }

  .control-section-header {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-secondary);
    letter-spacing: 0.07em;
    text-transform: uppercase;
    margin-bottom: 1rem;
    padding-bottom: 0.6rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }

  .control-section-header::before {
    content: '';
    width: 3px;
    height: 14px;
    background: var(--accent);
    border-radius: 2px;
    flex-shrink: 0;
  }

  #panelPhylogenetics .control-section-header::before { background: var(--rose); }
  #panelPhylogeography .control-section-header::before { background: var(--violet); }
  #panelHostTransmission .control-section-header::before { background: var(--gold); }
  #panelCustomCtmc .control-section-header::before { background: var(--lime); }

  #panelPhylogenetics:hover { border-color: color-mix(in srgb, var(--rose) 40%, var(--line)); }
  #panelPhylogeography:hover { border-color: color-mix(in srgb, var(--violet) 40%, var(--line)); }
  #panelHostTransmission:hover { border-color: color-mix(in srgb, var(--gold) 40%, var(--line)); }
  #panelCustomCtmc:hover { border-color: color-mix(in srgb, var(--lime) 40%, var(--line)); }

  .control-section-header .header-title {
    flex: 1;
    color: var(--text-primary);
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
  }

  .control-section-header input[type="checkbox"] {
    transform: scale(1.3);
    cursor: pointer;
    accent-color: var(--accent);
  }

  .control-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }

  .control-item-inline {
    display: flex;
    align-items: center;
    gap: 0.65rem;
  }

  .control-item-inline input[type="checkbox"] {
    transform: scale(1.2);
    cursor: pointer;
    accent-color: var(--accent);
  }

  .control-item-inline label {
    cursor: pointer;
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin: 0;
  }

  .custom-ctmc-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
  }

  .custom-ctmc-summary {
    color: var(--text-secondary);
    font-size: 0.88rem;
    line-height: 1.45;
  }

  .custom-model-transfer-status {
    min-height: 18px;
    color: var(--text-secondary);
    font-size: 0.8rem;
    line-height: 1.45;
  }

  .checkbox-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem 1rem;
  }


  /* ── Child controls ─────────────────────────────────────── */
  .child-controls {
    margin-left: 1.25rem;
    padding-left: 1rem;
    border-left: 2px solid var(--border-mid);
    margin-top: 0;
    display: flex;
    flex-direction: column;
    gap: 0.9rem;
  }

  .custom-model-editor-modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 2200;
    align-items: center;
    justify-content: center;
    padding: 28px 24px;
    background: var(--overlay-backdrop);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
  }

  .custom-model-editor-modal:not([hidden]) {
    display: flex;
  }

  .custom-model-editor-modal[hidden] {
    display: none !important;
  }

  .custom-model-editor {
    width: min(980px, 100%);
    max-height: min(88vh, 920px);
    overflow-y: auto;
    border: 1px solid var(--border);
    border-radius: 18px;
    background: var(--surface);
    padding: 1.3rem;
    display: grid;
    gap: 1rem;
    position: relative;
    box-shadow: var(--shadow-modal);
  }

  .custom-model-editor-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
  }

  .custom-model-editor-head h3 {
    margin: 0 0 0.35rem;
    color: var(--text-primary);
    font-size: 1.05rem;
  }

  .custom-model-editor-head p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.88rem;
    line-height: 1.5;
  }

  .custom-model-editor-summary {
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 0.9rem 1rem;
    display: grid;
    gap: 0.7rem;
    background: color-mix(in srgb, var(--white) 2%, var(--surface-2));
  }

  .custom-model-editor-summary.is-valid {
    border-color: var(--success-border);
    background: var(--success-surface);
  }

  .custom-model-editor-summary.is-warning {
    border-color: var(--warning-border);
    background: var(--warning-surface);
  }

  .custom-model-editor-summary.is-invalid {
    border-color: var(--danger-border);
    background: var(--danger-surface);
  }

  .custom-model-editor-summary-top {
    display: flex;
    flex-wrap: wrap;
    gap: 0.7rem;
    align-items: center;
    justify-content: space-between;
  }

  .custom-model-editor-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    border-radius: 999px;
    padding: 0.32rem 0.7rem;
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    border: 1px solid var(--border);
    color: var(--text-primary);
    background: color-mix(in srgb, var(--white) 4%, var(--surface-2));
  }

  .custom-model-editor-badge.is-valid {
    color: var(--success-ink);
    border-color: var(--success-border);
    background: var(--success-surface);
  }

  .custom-model-editor-badge.is-warning {
    color: var(--warning-ink);
    border-color: var(--warning-border);
    background: var(--warning-surface);
  }

  .custom-model-editor-badge.is-invalid {
    color: var(--danger-ink);
    border-color: var(--danger-border);
    background: var(--danger-surface);
  }

  .custom-model-editor-preview {
    color: var(--text-primary);
    font-size: 0.86rem;
    line-height: 1.5;
  }

  .custom-model-editor-summary-title {
    color: var(--text-primary);
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    margin-bottom: 0.35rem;
  }

  .custom-model-editor-list {
    margin: 0;
    padding-left: 1.15rem;
    display: grid;
    gap: 0.32rem;
    font-size: 0.84rem;
    line-height: 1.5;
  }

  .custom-model-editor-list.is-error {
    color: var(--danger-ink);
  }

  .custom-model-editor-list.is-warning {
    color: var(--warning-ink);
  }

  .custom-model-editor-grid {
    display: grid;
    gap: 0.75rem;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  }

  .custom-model-editor-grid label,
  .custom-model-editor-block label,
  .custom-model-state-card label {
    display: grid;
    gap: 0.4rem;
    color: var(--text-secondary);
    font-size: 0.84rem;
    font-weight: 700;
  }

  .custom-model-editor-grid input,
  .custom-model-editor-grid select,
  .custom-model-states-grid input,
  .custom-model-matrix-grid input {
    border: 1px solid var(--border-mid);
    border-radius: 12px;
    padding: 8px 10px;
    font: inherit;
    background: var(--bg);
    color: var(--text-primary);
  }

  .custom-model-editor-block {
    display: grid;
    gap: 0.65rem;
  }

  .custom-model-editor-note {
    color: var(--text-secondary);
    font-size: 0.82rem;
    line-height: 1.45;
  }

  .custom-model-states-grid {
    display: grid;
    gap: 0.75rem;
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  }

  .custom-model-state-card {
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 0.9rem;
    background: color-mix(in srgb, var(--white) 2%, var(--surface-2));
    display: grid;
    gap: 0.75rem;
  }

  .custom-model-state-card.is-invalid {
    border-color: var(--danger-border);
    background: var(--danger-surface);
  }

  .custom-model-state-card.is-warning {
    border-color: var(--warning-border);
    background: var(--warning-surface);
  }

  .custom-model-state-card-header {
    font-size: 0.74rem;
    font-weight: 800;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    text-transform: uppercase;
  }

  .custom-model-state-card input[type="color"] {
    padding: 0;
    min-height: 38px;
    background: transparent;
  }

  .custom-model-matrix-grid {
    overflow-x: auto;
  }

  .custom-model-matrix-grid table {
    width: 100%;
    min-width: 460px;
    border-collapse: collapse;
    overflow: hidden;
    border-radius: 14px;
    background: var(--bg);
  }

  .custom-model-matrix-grid th,
  .custom-model-matrix-grid td {
    border: 1px solid var(--border);
    padding: 8px;
    text-align: center;
  }

  .custom-model-matrix-grid th {
    background: color-mix(in srgb, var(--white) 3%, var(--surface-2));
    color: var(--text-secondary);
    font-size: 0.78rem;
    font-weight: 800;
  }

  .custom-model-matrix-grid input {
    width: 88px;
    text-align: center;
  }

  .custom-model-matrix-grid input:disabled {
    background: var(--input-disabled-bg);
    color: var(--text-muted);
    cursor: not-allowed;
  }

  .custom-model-grid-field.is-invalid {
    border-color: var(--danger-border) !important;
    box-shadow: 0 0 0 1px color-mix(in srgb, var(--danger-border) 65%, transparent);
  }

  .custom-model-grid-field.is-warning {
    border-color: var(--warning-border) !important;
    box-shadow: 0 0 0 1px color-mix(in srgb, var(--warning-border) 65%, transparent);
  }

  .custom-model-matrix-grid tr.is-warning th {
    color: var(--warning-ink);
  }

  .custom-model-matrix-grid tr.is-invalid th {
    color: var(--danger-ink);
  }

  .custom-model-editor-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    align-items: center;
  }

  .custom-model-editor-status {
    min-height: 20px;
    color: var(--text-secondary);
    font-size: 0.84rem;
    flex: 1 1 220px;
  }

  .custom-model-editor-actions button:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    border-color: var(--border);
    color: var(--text-muted);
    background: color-mix(in srgb, var(--white) 2%, var(--surface-2));
  }

  .custom-model-editor-close {
    position: static;
    flex-shrink: 0;
    margin-left: auto;
  }

  /* ── Panel visibility btn ───────────────────────────────── */
  .panel-visibility-btn {
    --panel-toggle-size: clamp(15.75px, 1.2375vw, 21.375px);
    --panel-toggle-icon-size: calc(var(--panel-toggle-size) * 0.68);
    width: var(--panel-toggle-size);
    height: var(--panel-toggle-size);
    min-width: var(--panel-toggle-size);
    min-height: var(--panel-toggle-size);
    border: 1px solid var(--border-mid);
    border-radius: 999px;
    background: var(--bg-elevated);
    cursor: pointer;
    transition: background 0.18s var(--ease), border-color 0.18s var(--ease);
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 0.5rem;
    box-shadow: none;
    transform: none;
    flex: 0 0 auto;
  }

  .panel-visibility-btn:hover {
    border-color: var(--accent);
    background: var(--bg-surface);
    transform: none;
    box-shadow: none;
  }

  .panel-visibility-btn.active {
    background: var(--accent-dark);
    border-color: transparent;
  }

  .panel-visibility-btn svg {
    width: var(--panel-toggle-icon-size);
    height: var(--panel-toggle-icon-size);
    display: block;
    overflow: visible;
  }

  .geo-legend-map {
    margin: 14px auto 0 auto;
    max-width: 720px;
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: 0 1px 2px color-mix(in srgb, var(--head) 8%, transparent);
    padding: 10px;
  }

  #countryMapCanvas {
    display: block;
    width: 100%;
    height: auto;
  }

  /* Icon states */
  #showPhyloPanelBtn:not(.active) svg *,
  #showGeoPanelBtn:not(.active) svg *,
  #showCustomCtmcPanelBtn:not(.active) svg * {
    fill: var(--text-secondary);
    stroke: var(--text-secondary);
  }

  #showPhyloPanelBtn:not(.active) svg [fill="none"],
  #showGeoPanelBtn:not(.active) svg [fill="none"],
  #showCustomCtmcPanelBtn:not(.active) svg [fill="none"] { fill: none; }

  #showPhyloPanelBtn.active svg *,
  #showGeoPanelBtn.active svg *,
  #showCustomCtmcPanelBtn.active svg * {
    fill: white;
    stroke: white;
  }

  #showPhyloPanelBtn.active svg [fill="none"],
  #showGeoPanelBtn.active svg [fill="none"],
  #showCustomCtmcPanelBtn.active svg [fill="none"] { fill: none; }

  #showHostPanelBtn:not(.active) svg { opacity: 0.35; }
  #showHostPanelBtn.active svg       { opacity: 1; }
  #showHostPanelBtn svg [fill="none"] { fill: none; }

  #showHostPanelBtn svg circle[fill],
  #showHostPanelBtn svg path[fill],
  #showHostPanelBtn svg rect[fill],
  #showHostPanelBtn svg ellipse[fill] { fill: white !important; }

  #showHostPanelBtn svg path[stroke],
  #showHostPanelBtn svg line[stroke],
  #showHostPanelBtn svg ellipse[stroke] { stroke: white !important; }

  /* ── Mode checkboxes ────────────────────────────────────── */
  .mode-checkboxes {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    margin-left: 20px;
    padding-left: 20px;
    border-left: 2px solid var(--border-mid);
  }

  .mode-checkbox {
    display: flex;
    align-items: center;
    gap: var(--toolbar-mode-gap, 0.42rem);
    min-width: 0;
    line-height: 1;
  }

  .mode-checkbox input[type="checkbox"] {
    width: var(--toolbar-checkbox-size, 1rem);
    height: var(--toolbar-checkbox-size, 1rem);
    flex: 0 0 var(--toolbar-checkbox-size, 1rem);
    transform: none;
    cursor: pointer;
    accent-color: var(--accent);
  }

  .mode-checkbox label {
    cursor: pointer;
    font-weight: 500;
    color: var(--text-secondary);
    font-size: var(--toolbar-label-font-size, 0.82rem);
    line-height: 1;
    white-space: nowrap;
  }

  /* ── Help button ────────────────────────────────────────── */
  .help-button {
    --help-button-size: 22px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--help-button-size);
    height: var(--help-button-size);
    min-width: var(--help-button-size);
    min-height: var(--help-button-size);
    border-radius: 50%;
    background: color-mix(in srgb, var(--white) 4%, var(--surface-2));
    border: 1px solid var(--line);
    color: var(--text-secondary);
    font-size: 0.78rem;
    font-weight: 700;
    line-height: 1;
    cursor: pointer;
    padding: 0;
    margin-left: 0;
    transition: background 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease), transform 0.15s var(--ease), box-shadow 0.18s var(--ease);
    box-shadow: none;
    vertical-align: middle;
    flex: 0 0 var(--help-button-size);
  }

  .help-button:hover {
    background: color-mix(in srgb, var(--accent) 18%, transparent);
    color: var(--head);
    border-color: color-mix(in srgb, var(--accent) 28%, transparent);
    transform: none;
    box-shadow: none;
  }

  .help-button:focus-visible,
  .help-modal-close:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
  }

  .help-modal[hidden] {
    display: none !important;
  }

  /* ── Help modal ─────────────────────────────────────────── */
  .help-modal {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--overlay-backdrop);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 32px 24px;
  }

  .help-modal.active { display: flex; }

  .help-modal-content {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 40px 44px 36px;
    width: min(820px, 100%);
    max-height: min(84vh, 860px);
    overflow-y: auto;
    box-shadow: var(--shadow-modal);
    position: relative;
    color: var(--text-primary);
  }

  .help-modal-close {
    position: absolute;
    top: 20px;
    right: 20px;
    background: color-mix(in srgb, var(--white) 4%, var(--surface-2));
    border: 1px solid var(--line);
    font-size: 22px;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background 0.18s var(--ease), color 0.18s var(--ease);
    box-shadow: none;
  }

  .help-modal-close:hover {
    background: color-mix(in srgb, var(--accent) 12%, var(--surface-2));
    border-color: color-mix(in srgb, var(--accent) 28%, transparent);
    color: var(--text-primary);
    transform: none;
    box-shadow: none;
  }

  .settings-close-button.help-modal-close {
    position: static;
    top: auto;
    right: auto;
    margin-left: auto;
  }

  .custom-model-editor .custom-model-editor-close.help-modal-close {
    position: absolute;
    top: 20px;
    right: 20px;
    margin-left: 0;
  }

  .help-modal h2 {
    margin: 0 56px 26px 0;
    color: var(--text-primary);
    font-size: clamp(1.85rem, 2vw, 2.5rem);
    line-height: 1.15;
    letter-spacing: -0.03em;
  }

  .help-modal h3 {
    margin: 28px 0 10px;
    color: var(--accent);
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
  }

  .help-modal p {
    margin: 0 0 1rem;
    line-height: 1.75;
    color: var(--text-secondary);
    font-size: 1.12rem;
  }

  .help-modal strong { color: var(--text-primary); }

  @media (max-width: 1120px) {
    :root:not([data-presentation="1"]) .button-group {
      grid-template-columns: max-content minmax(0, 1fr);
    }

    :root:not([data-presentation="1"]) .toolbar-modes,
    :root:not([data-presentation="1"]) .toolbar-history {
      grid-column: span 1;
    }
  }

  @media (max-width: 840px) {
    :root:not([data-presentation="1"]) .button-group {
      grid-template-columns: minmax(0, 1fr);
      gap: 0.8rem;
    }

    :root:not([data-presentation="1"]) .toolbar-actions {
      display: grid;
      grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) var(--toolbar-control-height);
      height: auto;
    }

    :root:not([data-presentation="1"]) .toolbar-tree-seed {
      grid-template-columns: minmax(0, 1fr);
    }

    :root:not([data-presentation="1"]) .toolbar-field-speed,
    :root:not([data-presentation="1"]) .toolbar-field-tree-size,
    :root:not([data-presentation="1"]) .toolbar-field-seed,
    :root:not([data-presentation="1"]) .toolbar-field-speed .slider-container,
    :root:not([data-presentation="1"]) .toolbar-field-tree-size #numTipsSelect,
    :root:not([data-presentation="1"]) .toolbar-field-seed #seedInput {
      width: 100%;
    }

    :root:not([data-presentation="1"]) .toolbar-field-speed .slider-container input[type="range"] {
      flex: 1 1 auto;
      width: 100%;
    }

    :root:not([data-presentation="1"]) .toolbar-modes {
      height: auto;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      grid-template-rows: auto;
      gap: 0.6rem;
      padding: 0;
      border-inline: 0;
    }

    :root:not([data-presentation="1"]) .toolbar-history {
      min-width: 0;
    }
  }

  @media (max-width: 720px) {
    .shell {
      padding: 0 16px;
    }

    .topbar-inner {
      padding: 12px 16px;
      align-items: flex-start;
    }

    .topnav {
      gap: 10px;
      font-size: 12px;
      justify-content: flex-end;
    }

    .hero {
      padding: 48px 0 24px;
    }

    .hero-grid {
      grid-template-columns: 1fr;
      gap: 20px;
    }

    .app-surface {
      padding: 18px 14px 18px;
      border-radius: 22px;
    }

    h1 {
      font-size: clamp(34px, 12vw, 54px);
    }

    .subtitle {
      font-size: 17px;
    }

    .settings-modal {
      padding: 16px;
    }

    .settings-dialog {
      padding: 20px;
      border-radius: 16px;
    }

    .custom-model-editor-modal {
      padding: 16px;
    }

    .custom-model-editor {
      width: 100%;
      max-height: 90vh;
      padding: 1rem;
      border-radius: 16px;
    }

    .custom-model-editor-head {
      gap: 0.8rem;
    }

    .custom-model-editor-grid {
      grid-template-columns: 1fr;
    }

    .settings-heading h2 {
      font-size: 1.5rem;
    }

    .settings-heading p,
    .settings-section-header p {
      font-size: 0.9rem;
    }

    .help-modal {
      padding: 16px;
    }

    .help-modal-content {
      width: 100%;
      max-height: 88vh;
      padding: 28px 24px 24px;
      border-radius: 16px;
    }

    .help-modal h2 {
      margin-right: 44px;
      font-size: 1.5rem;
    }

    .help-modal p {
      font-size: 1rem;
    }
  }

  @media (max-width: 720px) {
    :root[data-embed="1"]:not([data-presentation="1"]) body {
      font-size: 15px;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .shell,
    :root[data-embed="1"]:not([data-presentation="1"]) .app-workbench,
    :root[data-embed="1"]:not([data-presentation="1"]) .app-surface {
      padding: 0;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .canvas-wrapper {
      align-items: stretch;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .button-group {
      justify-content: stretch;
      gap: 0.55rem;
      margin-top: 0.75rem;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .button-group .control-item,
    :root[data-embed="1"]:not([data-presentation="1"]) .track-branches {
      width: 100%;
      align-items: stretch;
      justify-content: flex-start;
      padding-left: 0;
      border-left: 0;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .mode-checkboxes {
      flex: 1 1 100%;
      width: 100%;
      margin-left: 0;
      padding-left: 0.2rem;
      border-left: 0;
      flex-wrap: wrap;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .mode-checkbox input[type="checkbox"] {
      transform: none;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .button-group .slider-container {
      width: 100%;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .segmented {
      width: 100%;
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .segmented-btn {
      min-width: 0;
      padding-inline: 0.35rem;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .control-panel {
      grid-template-columns: minmax(0, 1fr);
      gap: 0.85rem;
      margin-top: 1rem;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .control-section {
      border-radius: 16px;
      padding: 1rem;
    }

    :root[data-embed="1"]:not([data-presentation="1"]) .checkbox-grid {
      grid-template-columns: minmax(0, 1fr);
    }
  }

  @media (max-width: 420px) {
    :root[data-embed="1"] .control-section-header {
      gap: 0.35rem;
    }

    :root[data-embed="1"] .control-item-inline {
      align-items: flex-start;
    }
  }

  /* Integrated website embeds should feel native: shrink controls instead of wrapping them. */
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) body {
    font-size: clamp(11px, 1.25vw, 15px);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) {
    --integrated-panel-scale: 1;
    --integrated-panel-width: 760px;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .button-group {
    --toolbar-control-height: 34px;
    --toolbar-tree-seed-control-height: calc(var(--toolbar-control-height) * 0.82);
    --history-control-height: 28px;
    --toolbar-label-height: 0.68rem;
    --toolbar-field-gap: 0.1rem;
    --toolbar-gap: 0.55rem;
    --toolbar-radius: 9px;
    --toolbar-tree-seed-gap: 0.36rem;
    --history-font-size: 0.62rem;
    --toolbar-speed-slider-width: 8.8rem;
    --toolbar-speed-value-width: 2rem;
    --toolbar-seed-width: 46px;
    --toolbar-tree-size-width: var(--toolbar-seed-width);
    --toolbar-button-gap: 0.24rem;
    --toolbar-button-padding-inline: 0.58rem;
    --toolbar-button-font-size: 0.74rem;
    --toolbar-icon-size: 0.98em;
    --toolbar-label-font-size: 0.68rem;
    --toolbar-number-font-size: 0.74rem;
    --toolbar-slider-value-font-size: 0.66rem;
    --toolbar-checkbox-size: 0.78rem;
    --toolbar-mode-gap: 0.24rem;
    --toolbar-segment-padding-inline: 0.36rem;
    display: grid;
    grid-auto-flow: column;
    grid-template-columns: max-content max-content max-content max-content max-content;
    align-items: end;
    justify-content: center;
    gap: var(--toolbar-gap);
    margin-top: 0.85rem;
    max-width: none;
    overflow: hidden;
    width: var(--integrated-panel-width);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .signature {
    transform: scale(var(--integrated-panel-scale));
    transform-origin: bottom right;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .button-group > .toolbar-section {
    min-width: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-actions {
    display: flex;
    align-self: center;
    align-items: center;
    flex-wrap: nowrap;
    gap: 0.3rem;
    height: var(--toolbar-control-height);
    justify-content: center;
    min-width: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-button {
    min-width: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-actions .icon-button {
    flex: 0 0 var(--toolbar-control-height);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-speed {
    width: calc(var(--toolbar-speed-slider-width) + var(--toolbar-speed-value-width) + 0.45rem);
    max-width: none;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-speed,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-speed .slider-container {
    width: 100%;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-speed .slider-container {
    gap: 0.38rem;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-speed .slider-container input[type="range"] {
    flex: 1 1 auto;
    width: 100%;
    min-width: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-tree-seed {
    --toolbar-tree-seed-control-height: calc(1.22rem * 0.75);
    --toolbar-label-height: 0.48rem;
    --toolbar-field-gap: 0.06rem;
    --toolbar-tree-seed-gap: 0.18rem;
    --toolbar-seed-width: 48px;
    --toolbar-tree-size-width: var(--toolbar-seed-width);
    --toolbar-number-font-size: 0.55rem;
    grid-template-columns: var(--toolbar-tree-size-width) var(--toolbar-seed-width);
    gap: var(--toolbar-tree-seed-gap);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-tree-size,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-tree-size #numTipsSelect,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-seed,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-field-seed #seedInput {
    width: var(--toolbar-seed-width);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) #numTipsSelect,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) #seedInput {
    min-height: 0;
    border-radius: 7px;
    padding-inline: 8px;
    font-size: 0.55rem;
    font-weight: 550;
    line-height: 1;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-modes {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: repeat(2, minmax(0, 1fr));
    gap: 0.12rem;
    height: var(--toolbar-control-height);
    min-width: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .mode-checkbox {
    gap: var(--toolbar-mode-gap);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .toolbar-history {
    --history-control-height: 0.92rem;
    --history-font-size: 0.46rem;
    --toolbar-label-height: 0.48rem;
    --toolbar-field-gap: 0.06rem;
    --toolbar-segment-padding-inline: 0.28rem;
    width: max-content;
    min-width: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .segmented {
    width: 100%;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .button-group .control-item,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .track-branches {
    width: auto;
    align-items: stretch;
    justify-content: flex-start;
    padding-left: 0;
    border-left: 0;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-panel {
    --panel-label-font-size: clamp(0.5rem, 1vw, 0.7rem);
    --panel-label-line-height: 1.15;
    --panel-slider-value-font-size: clamp(0.5rem, 0.96vw, 0.66rem);
    --panel-slider-value-width: clamp(1.55rem, 3vw, 2rem);
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(0.35rem, 1.1vw, 1rem);
    margin-top: clamp(0.55rem, 1.4vw, 1rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-panel,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .button-group,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .custom-ctmc-launcher,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .custom-ctmc-panel-row {
    transform-origin: top left;
  }

  @supports (zoom: 1) {
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-panel,
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .button-group,
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .custom-ctmc-launcher,
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .custom-ctmc-panel-row {
      width: var(--integrated-panel-width);
      max-width: none;
      zoom: var(--integrated-panel-scale);
    }
  }

  @supports not (zoom: 1) {
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-panel,
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .button-group,
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .custom-ctmc-launcher,
    :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .custom-ctmc-panel-row {
      width: var(--integrated-panel-width);
      max-width: none;
      transform: scale(var(--integrated-panel-scale));
    }
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-section {
    min-width: 0;
    border-radius: clamp(10px, 1.4vw, 16px);
    padding: clamp(0.55rem, 1.25vw, 1rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-section:hover {
    transform: none;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-section-header {
    gap: clamp(0.18rem, 0.55vw, 0.36rem);
    margin-bottom: clamp(0.42rem, 0.85vw, 0.75rem);
    padding-bottom: clamp(0.26rem, 0.55vw, 0.45rem);
    font-size: clamp(0.44rem, 0.92vw, 0.66rem);
    letter-spacing: 0.04em;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-section-header::before {
    width: 2px;
    height: clamp(8px, 1.25vw, 12px);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-section-header .header-title {
    min-width: 0;
    gap: clamp(0.14rem, 0.45vw, 0.3rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-section-header input[type="checkbox"],
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-item-inline input[type="checkbox"] {
    transform: scale(0.9);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-group,
  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .child-controls {
    gap: clamp(0.32rem, 0.85vw, 0.7rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .child-controls {
    margin-left: clamp(0.28rem, 0.75vw, 0.65rem);
    padding-left: clamp(0.35rem, 0.8vw, 0.7rem);
    border-left-width: 1px;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-item {
    gap: clamp(0.16rem, 0.48vw, 0.32rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-item-inline {
    gap: clamp(0.2rem, 0.62vw, 0.46rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .control-item-inline label {
    font-size: clamp(0.5rem, 1vw, 0.7rem);
    line-height: 1.15;
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .checkbox-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(0.16rem, 0.52vw, 0.36rem);
  }

  :root[data-embed="1"][data-integrated="1"]:not([data-presentation="1"]) .help-button {
    --help-button-size: clamp(0.82rem, 1.65vw, 1.05rem);
    font-size: clamp(0.48rem, 0.92vw, 0.62rem);
  }

  /* ── Misc ───────────────────────────────────────────────── */
  .control-stack { display: flex; flex-direction: column; gap: 10px; }

  .info {
    text-align: center;
    margin-top: 1rem;
    color: var(--text-muted);
    font-size: 0.9rem;
  }

  /* ── Scrollbar ──────────────────────────────────────────── */
  ::-webkit-scrollbar { width: 6px; }
  ::-webkit-scrollbar-track { background: var(--bg); }
  ::-webkit-scrollbar-thumb { background: var(--border-mid); border-radius: 3px; }
  ::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }