:root {
      --bg: #121316;
      --panel-bg: #1a1b20;
      --panel-border: #2a2c36;
      --accent: #3b82f6;
      --text: #e2e8f0;
      --text-muted: #8b949e;
      --col-smooth: #94a3b8;
      --col-detail: #eab308;
      --col-hover: #00e5ff;
      --col-selected: #ffffff;
    }
    * { box-sizing: border-box; }
    body {
      margin: 0;
      overflow: hidden;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
      display: flex;
      flex-direction: column;
      height: 100vh;
      width: 100vw;
      background: var(--bg);
      color: var(--text);
      user-select: none;
    }
    #top-bar {
      height: 50px;
      background: #111318;
      border-bottom: 1px solid var(--panel-border);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 16px;
      gap: 16px;
      flex-shrink: 0;
      z-index: 20;
    }
    .top-bar-left {
      display: flex;
      align-items: center;
      gap: 14px;
      flex-shrink: 0;
    }
    .brand {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .brand-title {
      font-size: 14px;
      font-weight: 700;
      letter-spacing: -0.01em;
      white-space: nowrap;
    }
    .badge-fps {
      font-size: 9px;
      background: #232733;
      color: #58a6ff;
      padding: 2px 6px;
      border-radius: 4px;
      font-weight: 600;
      letter-spacing: 0.05em;
      white-space: nowrap;
    }
    .top-open-btn {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 5px 12px;
      cursor: pointer;
      white-space: nowrap;
      font-size: 12px;
      font-weight: 600;
    }
    .top-bar-center {
      display: flex;
      align-items: center;
      gap: 12px;
      flex: 1;
      justify-content: center;
      min-width: 0;
    }
    .active-brush-pill {
      background: #15161c;
      padding: 4px 10px;
      border-radius: 6px;
      border: 1px solid var(--panel-border);
      display: flex;
      align-items: center;
      gap: 6px;
      flex-shrink: 0;
    }
    .shortcut-hints {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-shrink: 0;
    }
    .hint-chip {
      font-size: 11px;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 4px;
      white-space: nowrap;
    }
    kbd {
      font-family: inherit;
      font-size: 10px;
      font-weight: 700;
      background: rgba(255, 255, 255, 0.1);
      color: var(--text);
      padding: 1px 5px;
      border-radius: 3px;
      border: 1px solid rgba(255, 255, 255, 0.15);
      box-shadow: 0 1px 1px rgba(0,0,0,0.3);
    }
    .tool-mode-btn kbd {
      font-size: 9px;
      padding: 1px 4px;
      border-radius: 3px;
      background: rgba(255, 255, 255, 0.15);
      border: 1px solid rgba(255, 255, 255, 0.2);
      color: inherit;
    }
    .top-bar-right {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-shrink: 0;
    }
    .stat-chip {
      background: #15161c;
      border: 1px solid var(--panel-border);
      padding: 4px 8px;
      border-radius: 5px;
      display: flex;
      align-items: center;
      gap: 5px;
      font-size: 11px;
      white-space: nowrap;
    }
    .stat-chip-label {
      color: var(--text-muted);
      font-weight: 500;
    }
    .stat-chip-val {
      color: var(--text);
      font-family: monospace;
      font-weight: 600;
    }
    #app-workspace {
      display: flex;
      flex: 1;
      min-height: 0;
      position: relative;
      overflow: hidden;
      width: 100vw;
    }
    #canvas-container {
      flex: 1;
      height: 100%;
      position: relative;
      outline: none;
    }
    #drop-overlay {
      position: absolute;
      inset: 20px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      background: rgba(18, 19, 22, 0.88);
      border: 2px dashed #475569;
      border-radius: 12px;
      pointer-events: none;
      z-index: 50;
      transition: opacity 0.2s, border-color 0.2s, background-color 0.2s;
    }
    #drop-overlay.hidden { display: none; }
    #drop-overlay.drag-active {
      display: flex !important;
      border-color: #3b82f6;
      background: rgba(18, 24, 38, 0.94);
      box-shadow: 0 0 35px rgba(59, 130, 246, 0.35);
    }
    #drop-overlay h2 { margin: 0 0 8px 0; font-size: 22px; color: #f8fafc; }
    #drop-overlay p { margin: 0; color: var(--text-muted); font-size: 14px; }

    #ui {
      width: 360px;
      height: 100%;
      background: var(--panel-bg);
      padding: 14px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      border-left: 1px solid var(--panel-border);
      overflow-y: auto;
      z-index: 10;
    }
    .panel-section {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .section-title {
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: var(--text-muted);
    }
    .btn {
      background: #252732;
      color: var(--text);
      border: 1px solid var(--panel-border);
      padding: 7px 12px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 500;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      transition: background 0.15s, border-color 0.15s;
    }
    .btn:hover { background: #303342; border-color: #42465a; }
    .btn:active { background: #1c1d25; }
    .btn-primary { background: var(--accent); color: white; border-color: #2563eb; }
    .btn-primary:hover { background: #2563eb; }

    .stat-row {
      display: flex;
      justify-content: space-between;
      font-size: 12px;
      color: var(--text-muted);
      padding: 2px 0;
    }
    .stat-row span:last-child {
      color: var(--text);
      font-family: monospace;
      font-weight: 600;
    }

    /* Distribution Bar */
    .dist-bar-container {
      display: flex;
      height: 12px;
      border-radius: 6px;
      overflow: hidden;
      background: #282a36;
      margin: 4px 0;
      border: 1px solid #363949;
    }
    .dist-segment {
      height: 100%;
      transition: width 0.25s ease;
    }

    /* Controls box */
    .control-box {
      background: #15161a;
      padding: 12px;
      border-radius: 8px;
      border: 1px solid var(--panel-border);
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .slider-header {
      display: flex;
      justify-content: space-between;
      font-size: 12px;
      margin-bottom: 4px;
    }
    .slider-header b {
      font-family: monospace;
      color: #f1f5f9;
    }
    input[type="range"] {
      width: 100%;
      accent-color: var(--accent);
      cursor: pointer;
      margin: 0;
    }

    /* Category Cards */
    .category-cards {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .cat-card {
      background: #21232c;
      border: 1px solid var(--panel-border);
      padding: 9px 12px;
      border-radius: 6px;
      display: flex;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      transition: border-color 0.15s, background 0.15s;
      position: relative;
    }
    .cat-card:hover { border-color: #43475b; }
    .cat-card.active-brush {
      border-color: #3b82f6;
      background: #1e2433;
      box-shadow: 0 0 0 1px #3b82f6;
    }
    .cat-card.active-cat { border-color: rgba(255,255,255,0.6); }
    .cat-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .cat-left {
      display: flex;
      align-items: center;
      gap: 6px;
      font-weight: 600;
      font-size: 12px;
      flex: 1;
      min-width: 0;
      margin-right: 6px;
    }
    .group-num-badge {
      font-family: monospace;
      font-size: 11px;
      font-weight: 700;
      color: var(--text-muted);
      background: rgba(255, 255, 255, 0.08);
      padding: 1px 5px;
      border-radius: 3px;
      flex-shrink: 0;
      line-height: 1.2;
    }
    .group-color-input {
      -webkit-appearance: none;
      -moz-appearance: none;
      appearance: none;
      width: 18px;
      height: 18px;
      border: 1px solid rgba(255, 255, 255, 0.25);
      border-radius: 4px;
      cursor: pointer;
      background: transparent;
      padding: 0;
      margin: 0;
      flex-shrink: 0;
      box-shadow: 0 1px 3px rgba(0,0,0,0.4);
      transition: transform 0.1s, border-color 0.15s;
    }
    .paint-match-badge {
      margin-top: 4px;
      padding: 4px 8px;
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 4px;
      font-size: 11px;
      display: flex;
      align-items: center;
      gap: 8px;
      transition: background 0.15s;
    }
    .paint-match-badge:hover {
      background: rgba(255, 255, 255, 0.07);
    }
    .paint-swatch-compare {
      width: 16px;
      height: 16px;
      border-radius: 3px;
      border: 1px solid rgba(255, 255, 255, 0.3);
      flex-shrink: 0;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
    }
    .paint-info {
      display: flex;
      flex-direction: column;
      overflow: hidden;
      line-height: 1.25;
    }
    .paint-name {
      font-weight: 600;
      color: #f1f5f9;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .paint-detail {
      font-size: 10px;
      color: #94a3b8;
    }
    .group-color-input:hover {
      transform: scale(1.15);
      border-color: #ffffff;
    }
    .group-color-input::-webkit-color-swatch-wrapper {
      padding: 0;
      border-radius: 3px;
    }
    .group-color-input::-webkit-color-swatch {
      border: none;
      border-radius: 3px;
    }
    .group-color-input::-moz-color-swatch {
      border: none;
      border-radius: 3px;
    }
    .group-color-hex {
      font-family: monospace;
      font-size: 10px;
      color: var(--text-muted);
      background: rgba(255, 255, 255, 0.06);
      padding: 1px 4px;
      border-radius: 3px;
      letter-spacing: 0.5px;
      cursor: pointer;
      user-select: all;
      flex-shrink: 0;
      transition: all 0.15s;
    }
    .group-color-hex:hover {
      color: var(--text);
      background: rgba(255, 255, 255, 0.14);
    }
    .group-name-input {
      background: transparent;
      border: 1px solid transparent;
      color: var(--text);
      font-size: 12px;
      font-weight: 600;
      font-family: inherit;
      padding: 2px 4px;
      border-radius: 4px;
      flex: 1;
      min-width: 0;
      outline: none;
      transition: all 0.15s;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .group-name-input:hover {
      border-color: #363949;
      background: rgba(255, 255, 255, 0.04);
    }
    .group-name-input:focus {
      border-color: #3b82f6;
      background: #14151a;
      box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.35);
    }
    .cat-dot {
      width: 12px;
      height: 12px;
      border-radius: 3px;
    }
    .cat-stats {
      display: flex;
      justify-content: space-between;
      font-size: 11px;
      color: var(--text-muted);
    }
    .cat-stats b {
      color: var(--text);
      font-family: monospace;
    }

    /* Brush indicator tag */
    .brush-tag {
      font-size: 9px;
      background: #2563eb;
      color: white;
      padding: 1px 5px;
      border-radius: 3px;
      font-weight: 700;
      letter-spacing: 0.05em;
    }

    /* Tooltip / Inspector */
    #surface-inspector {
      position: absolute;
      bottom: 16px;
      left: 16px;
      background: rgba(18, 20, 26, 0.92);
      border: 1px solid #333846;
      padding: 8px 14px;
      border-radius: 6px;
      font-size: 12px;
      color: #e2e8f0;
      pointer-events: none;
      display: none;
      z-index: 30;
      line-height: 1.5;
      box-shadow: 0 4px 12px rgba(0,0,0,0.5);
    }

    #loading-indicator {
      display: none;
      position: absolute;
      top: 16px;
      left: 16px;
      background: rgba(15, 17, 23, 0.92);
      border: 1px solid #30363d;
      padding: 8px 14px;
      border-radius: 6px;
      font-size: 12px;
      color: #58a6ff;
      z-index: 40;
    }

    /* Tool Buttons & Selection Marquee */
    .tool-btn-group {
      display: flex;
      gap: 4px;
      background: #14151a;
      padding: 3px;
      border-radius: 8px;
      border: 1px solid var(--panel-border);
    }
    .tool-mode-btn {
      flex: 1;
      font-size: 11px;
      padding: 6px 8px;
      border-radius: 5px;
      border: 1px solid transparent;
      background: transparent;
      color: var(--text-muted);
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 5px;
      transition: all 0.15s;
    }
    .tool-mode-btn:hover {
      color: var(--text);
      background: #252834;
    }
    .tool-mode-btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #3b82f6;
      font-weight: 600;
      box-shadow: 0 1px 4px rgba(37, 99, 235, 0.4);
    }

    #selection-marquee {
      position: absolute;
      border: 1.5px dashed #38bdf8;
      background: rgba(56, 189, 248, 0.18);
      pointer-events: none;
      display: none;
      z-index: 45;
      border-radius: 2px;
      box-shadow: 0 0 10px rgba(56, 189, 248, 0.25);
    }

    #radius-cursor-ring {
      position: absolute;
      border: 1.5px solid #38bdf8;
      background: rgba(56, 189, 248, 0.1);
      border-radius: 50%;
      pointer-events: none;
      display: none;
      z-index: 46;
      transform: translate(-50%, -50%);
    }

    /* Floating Reassignment Popup */
    #group-popup {
      position: absolute;
      background: #1c1e27;
      border: 1px solid #3b82f6;
      box-shadow: 0 12px 36px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(59, 130, 246, 0.3);
      border-radius: 8px;
      padding: 12px 14px;
      z-index: 100;
      width: 275px;
      color: #e2e8f0;
      display: none;
    }
    .popup-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .popup-badge {
      background: #272a38;
      border: 1px solid #3b82f6;
      color: #60a5fa;
      font-size: 12px;
      font-weight: 700;
      padding: 2px 8px;
      border-radius: 4px;
    }
    .popup-close {
      background: transparent;
      border: none;
      color: #94a3b8;
      font-size: 18px;
      cursor: pointer;
      padding: 0;
      line-height: 1;
    }
    .popup-close:hover { color: #f1f5f9; }
    
    .popup-cat-buttons {
      display: flex;
      flex-direction: column;
      gap: 6px;
      margin-top: 10px;
    }
    .btn-cat-choice {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 7px 10px;
      border-radius: 6px;
      background: #252834;
      border: 1px solid #363949;
      color: #e2e8f0;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      transition: all 0.15s;
    }
    .btn-cat-choice:hover {
      filter: brightness(1.2);
      border-color: #58a6ff;
    }
    .btn-cat-choice.active {
      border-color: #3b82f6;
      background: #2b3248;
    }

    .popup-pills-container {
      display: flex;
      flex-wrap: wrap;
      gap: 5px;
      margin-top: 6px;
      max-height: 60px;
      overflow-y: auto;
    }
    .group-pill {
      padding: 3px 8px;
      border-radius: 4px;
      font-size: 11px;
      font-weight: 600;
      cursor: pointer;
      border: 1px solid #363949;
      display: inline-flex;
      align-items: center;
      gap: 5px;
      background: #282b37;
      color: #e2e8f0;
      transition: all 0.15s;
    }
    .group-pill:hover {
      filter: brightness(1.25);
      border-color: #58a6ff;
    }
    #popup-group-input {
      width: 70px;
      background: #121318;
      border: 1px solid #363a4d;
      color: white;
      border-radius: 6px;
      padding: 5px 8px;
      font-size: 12px;
      font-weight: 700;
      text-align: center;
      outline: none;
    }
    #popup-group-input:focus {
      border-color: #3b82f6;
      box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.25);
    }

    /* Custom Groups */
    .group-card {
      background: #15161a;
      border: 1px solid var(--panel-border);
      border-radius: 6px;
      padding: 7px 10px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      transition: border-color 0.15s;
      cursor: pointer;
    }
    .group-card:hover { border-color: #42465a; }
    .group-card.active-brush { border-color: #3b82f6; background: #1e2433; }
    .group-card-left {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 12px;
      font-weight: 600;
      flex: 1;
      min-width: 0;
      margin-right: 6px;
    }
    .group-card-color {
      width: 12px;
      height: 12px;
      border-radius: 3px;
    }
    .group-card-stats {
      font-size: 11px;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .btn-icon {
      background: transparent;
      border: none;
      color: #8b949e;
      cursor: pointer;
      font-size: 14px;
      padding: 2px 4px;
      border-radius: 3px;
      line-height: 1;
    }
    .btn-icon:hover { color: #ef4444; background: rgba(239, 68, 68, 0.15); }

    /* Unified paint groups list */
    #paint-groups-list {
      display: flex;
      flex-direction: column;
      gap: 4px;
      max-height: 300px;
      overflow-y: auto;
      padding-right: 2px;
    }
    .pg-row {
      display: flex;
      align-items: center;
      gap: 6px;
      padding: 6px 10px;
      border-radius: 6px;
      background: #15161a;
      border: 1px solid var(--panel-border);
      cursor: pointer;
      transition: border-color 0.15s, background 0.15s;
      border-left: 3px solid transparent;
    }
    .pg-row:hover { border-color: #43475b; background: #1c1d24; }
    .pg-row.active-brush { border-left-color: #3b82f6; background: #1a1e2e; }
    .pg-row-color {
      width: 14px;
      height: 14px;
      border-radius: 3px;
      border: 1px solid rgba(255,255,255,0.2);
      flex-shrink: 0;
    }
    .pg-row-name {
      background: transparent;
      border: 1px solid transparent;
      color: var(--text);
      font-size: 12px;
      font-weight: 600;
      font-family: inherit;
      padding: 1px 3px;
      border-radius: 3px;
      flex: 1;
      min-width: 0;
      outline: none;
      transition: all 0.12s;
    }
    .pg-row-name:hover { border-color: #363949; background: rgba(255,255,255,0.04); }
    .pg-row-name:focus { border-color: #3b82f6; background: #14151a; }
    .pg-row-pct { font-size: 11px; color: var(--text-muted); font-family: monospace; flex-shrink: 0; }
    .pg-row-badge { font-size: 9px; background: #2563eb; color: white; padding: 1px 4px; border-radius: 3px; font-weight: 700; flex-shrink: 0; display: none; }
    .pg-row.active-brush .pg-row-badge { display: inline-block; }
    .pg-row-del { background: transparent; border: none; color: #555; cursor: pointer; font-size: 14px; padding: 0 2px; line-height: 1; flex-shrink: 0; }
    .pg-row-del:hover { color: #ef4444; }
    .pg-paint-match { margin-top: 3px; margin-left: 20px; font-size: 10px; color: #94a3b8; display: flex; align-items: center; gap: 5px; }
    .pg-paint-swatch { width: 10px; height: 10px; border-radius: 2px; flex-shrink: 0; border: 1px solid rgba(255,255,255,0.2); }

    /* Gizmo cube canvas */
    #gizmo-canvas {
      position: absolute;
      bottom: 20px;
      right: 20px;
      width: 90px;
      height: 90px;
      z-index: 35;
      cursor: pointer;
      border-radius: 8px;
      display: none; /* shown after mesh loaded */
    }

    /* Settings Modal */
    #settings-modal {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.7);
      z-index: 200;
      display: none;
      align-items: center;
      justify-content: center;
    }
    #settings-modal.open { display: flex; }
    .settings-dialog {
      background: #1a1b20;
      border: 1px solid var(--panel-border);
      border-radius: 10px;
      padding: 20px;
      width: 400px;
      max-width: 95vw;
      max-height: 85vh;
      overflow-y: auto;
      display: flex;
      flex-direction: column;
      gap: 16px;
      box-shadow: 0 24px 64px rgba(0,0,0,0.8);
    }
    .settings-dialog h2 {
      margin: 0;
      font-size: 15px;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .settings-close {
      background: transparent;
      border: none;
      color: #94a3b8;
      font-size: 20px;
      cursor: pointer;
      padding: 0;
      line-height: 1;
    }
    .settings-close:hover { color: #f1f5f9; }
    .settings-section-title {
      font-size: 10px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: var(--text-muted);
      margin-bottom: 8px;
    }
    .settings-row {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 12px;
      margin-bottom: 8px;
    }
    .settings-row label { flex: 1; color: var(--text); }
    .settings-row input[type="range"] { width: 110px; }
    .settings-row .settings-val { font-family: monospace; font-size: 11px; width: 36px; text-align: right; color: var(--text-muted); }
    .settings-keybind {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 12px;
      padding: 5px 8px;
      background: #15161a;
      border-radius: 5px;
      margin-bottom: 4px;
      border: 1px solid var(--panel-border);
    }
    .settings-keybind label { flex: 1; color: var(--text); }
    .keybind-btn {
      background: #252732;
      border: 1px solid var(--panel-border);
      color: var(--text);
      font-size: 12px;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: 4px;
      cursor: pointer;
      min-width: 36px;
      text-align: center;
      transition: background 0.1s, border-color 0.1s;
    }
    .keybind-btn.listening { background: #2563eb; border-color: #3b82f6; color: white; }
    .theme-toggle {
      display: flex;
      gap: 6px;
    }
    .theme-btn {
      flex: 1;
      padding: 7px;
      border-radius: 6px;
      border: 1px solid var(--panel-border);
      background: #252732;
      color: var(--text);
      font-size: 12px;
      cursor: pointer;
      text-align: center;
      transition: all 0.15s;
    }
    .theme-btn.active { background: #3b82f6; border-color: #2563eb; color: white; }

    /* Light theme overrides */
    body.light-theme {
      --bg: #f0f2f7;
      --panel-bg: #ffffff;
      --panel-border: #d1d5db;
      --text: #111827;
      --text-muted: #6b7280;
    }
    body.light-theme #top-bar { background: #e5e7eb; }
    body.light-theme .btn { background: #e9ebf0; color: #111827; border-color: #d1d5db; }
    body.light-theme .btn:hover { background: #d1d5db; }
    body.light-theme .pg-row { background: #f5f7fa; }
    body.light-theme .pg-row:hover { background: #eaedf2; }
    body.light-theme .pg-row.active-brush { background: #dbeafe; }
    body.light-theme .control-box { background: #f0f2f7; }
    body.light-theme .cat-card { background: #f5f7fa; }
    body.light-theme #settings-modal .settings-dialog { background: #ffffff; }

    /* Toast Notifications */
    #toast-container {
      position: fixed;
      bottom: 24px;
      left: 50%;
      transform: translateX(-50%);
      display: flex;
      flex-direction: column;
      gap: 8px;
      z-index: 9999;
      pointer-events: none;
    }
    .toast {
      padding: 9px 16px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 600;
      color: #fff;
      background: #1c1f2b;
      border: 1px solid #3b82f6;
      box-shadow: 0 8px 24px rgba(0,0,0,0.6);
      pointer-events: auto;
      transition: opacity 0.25s ease, transform 0.25s ease;
      animation: toast-in 0.2s ease-out;
    }
    .toast-error { background: #2a1215; border-color: #ef4444; color: #fca5a5; }
    .toast-warning { background: #2d2010; border-color: #f59e0b; color: #fde68a; }
    .toast-success { background: #0e291c; border-color: #10b981; color: #a7f3d0; }
    .toast.fade-out { opacity: 0; transform: translateY(8px); }
    @keyframes toast-in {
      from { opacity: 0; transform: translateY(12px); }
      to { opacity: 1; transform: translateY(0); }
    }

    /* Responsive adjustments */
    @media (max-width: 1080px) {
      .stat-chip[title="Total surface area"] { display: none; }
      .stat-chip[title="Total triangles"] { display: none; }
    }
    @media (max-width: 860px) {
      #top-bar { padding: 0 10px; gap: 8px; }
      .stat-chip { padding: 3px 6px; font-size: 10px; }
      .brand-title { display: none; }
    }
    /* ── Color Recommender Modal ─────────────────────────────────────────────── */
    #color-recommender-modal {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.65);
      display: none;
      align-items: center;
      justify-content: center;
      z-index: 600;
    }
    #color-recommender-modal.open { display: flex; }

    .crec-dialog {
      background: var(--panel-bg);
      border: 1px solid var(--panel-border);
      border-radius: 14px;
      width: 480px;
      max-width: 96vw;
      max-height: 90vh;
      overflow-y: auto;
      box-shadow: 0 24px 64px rgba(0,0,0,0.6);
      display: flex;
      flex-direction: column;
    }
    .crec-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 14px 18px 12px;
      border-bottom: 1px solid var(--panel-border);
      flex-shrink: 0;
    }
    .crec-header h3 {
      margin: 0;
      font-size: 14px;
      font-weight: 700;
      color: var(--text);
      display: flex;
      align-items: center;
      gap: 7px;
    }
    .crec-body {
      padding: 16px 18px;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    /* Slots */
    .crec-slots {
      display: flex;
      gap: 10px;
    }
    .crec-slot {
      flex: 1;
      height: 62px;
      border-radius: 10px;
      cursor: pointer;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2px;
      transition: border-color 0.15s, transform 0.1s;
      user-select: none;
      position: relative;
    }
    .crec-slot:hover { transform: scale(1.03); }
    .crec-slot-num  { font-size: 18px; font-weight: 800; line-height: 1; }
    .crec-slot-hex  { font-size: 9px; font-family: monospace; }
    .crec-slot-clear {
      position: absolute;
      top: 3px; right: 5px;
      background: none; border: none;
      color: rgba(255,255,255,0.45);
      cursor: pointer; font-size: 13px; padding: 0; line-height: 1;
    }
    .crec-slot-clear:hover { color: #fff; }

    /* Wheel area */
    .crec-wheel-row {
      display: flex;
      gap: 16px;
      align-items: flex-start;
    }
    #crec-wheel {
      border-radius: 50%;
      cursor: crosshair;
      flex-shrink: 0;
      border: 2px solid var(--panel-border);
      display: block;
    }
    .crec-wheel-controls {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 10px;
      min-width: 0;
    }
    #crec-step-label {
      font-size: 11px;
      font-weight: 700;
      color: #60a5fa;
    }
    #crec-preview-bar {
      width: 100%;
      height: 48px;
      border-radius: 8px;
      border: 2px solid var(--panel-border);
      display: flex;
      align-items: center;
      justify-content: center;
      transition: background 0.15s;
    }
    #crec-preview-hex {
      font-size: 12px;
      font-family: monospace;
      font-weight: 700;
      mix-blend-mode: difference;
      color: #fff;
    }
    .crec-lightness-row {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 11px;
      color: var(--text-muted);
    }
    .crec-lightness-row input[type=range] { flex: 1; }
    #crec-lightness-val { min-width: 28px; text-align: right; }

    .crec-hex-row {
      display: flex;
      gap: 6px;
      align-items: center;
    }
    #crec-hex-input {
      flex: 1;
      padding: 6px 8px;
      border-radius: 4px;
      background: #121318;
      border: 1px solid var(--panel-border);
      color: #e2e8f0;
      font-size: 12px;
      font-family: monospace;
      outline: none;
      min-width: 0;
    }
    #crec-hex-input:focus { border-color: #60a5fa; }
    .crec-hex-hint {
      font-size: 10px;
      color: var(--text-muted);
      margin-top: -4px;
    }

    /* Recommendations */
    .crec-recs-section {
      border-top: 1px solid var(--panel-border);
      padding-top: 12px;
    }
    .crec-recs-title {
      font-size: 11px;
      font-weight: 600;
      color: #94a3b8;
      margin-bottom: 8px;
    }
    .crec-hint {
      font-size: 11px;
      color: #64748b;
      padding: 6px 0;
    }
    .crec-recs-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }
    .crec-rec {
      cursor: pointer;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 3px;
      border-radius: 8px;
      padding: 5px;
      background: #16181f;
      border: 1px solid #2d3748;
      transition: border-color 0.12s;
    }
    .crec-rec-swatch {
      width: 38px;
      height: 38px;
      border-radius: 7px;
      border: 1px solid rgba(255,255,255,0.08);
    }
    .crec-rec-label {
      font-size: 9px;
      color: #94a3b8;
      text-align: center;
      line-height: 1.2;
      max-width: 52px;
    }
    .crec-rec-hex {
      font-size: 8px;
      color: #64748b;
      font-family: monospace;
    }

    /* Footer */
    .crec-footer {
      display: flex;
      gap: 8px;
      padding: 12px 18px;
      border-top: 1px solid var(--panel-border);
      flex-shrink: 0;
    }
    #crec-apply-row {
      display: none;
      gap: 8px;
      flex: 1;
    }
    .crec-apply-btn {
      flex: 1;
      padding: 8px 12px;
      border-radius: 7px;
      font-size: 12px;
      font-weight: 700;
      cursor: pointer;
      border: none;
      background: #1d4ed8;
      color: #fff;
      transition: background 0.15s;
    }
    .crec-apply-btn:hover { background: #2563eb; }
    .crec-cancel-btn {
      padding: 8px 14px;
      border-radius: 7px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      background: #1e2433;
      border: 1px solid var(--panel-border);
      color: var(--text-muted);
      flex-shrink: 0;
    }
    .crec-cancel-btn:hover { color: var(--text); }

    /* Shape Tool Styles */
    .shape-type-btn.active,
    .shape-transform-btn.active {
      background: var(--primary) !important;
      color: #fff !important;
      border-color: var(--primary) !important;
    }
    #btn-shape-snap-toggle.active {
      background: #0284c7 !important;
      color: #fff !important;
      border-color: #38bdf8 !important;
    }
    .shape-num-input {
      width: 100%;
      background: #15161c;
      border: 1px solid var(--panel-border);
      border-radius: 4px;
      color: var(--text);
      font-size: 11px;
      font-family: monospace;
      padding: 4px 6px;
      outline: none;
      box-sizing: border-box;
    }
    .shape-num-input:focus {
      border-color: var(--primary);
    }

    /* ── Tutorial Modal & Feature Guide ─────────────────────────────────────── */
    #tutorial-modal {
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.75);
      backdrop-filter: blur(4px);
      display: none;
      align-items: center;
      justify-content: center;
      z-index: 650;
      padding: 16px;
    }
    #tutorial-modal.open {
      display: flex;
    }
    .tutorial-dialog {
      background: #1a1b20;
      border: 1px solid var(--panel-border);
      border-radius: 12px;
      width: 840px;
      max-width: 96vw;
      height: 86vh;
      max-height: 820px;
      display: flex;
      flex-direction: column;
      box-shadow: 0 24px 64px rgba(0, 0, 0, 0.85);
      overflow: hidden;
    }
    .tutorial-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 14px 20px;
      background: #14151a;
      border-bottom: 1px solid var(--panel-border);
      flex-shrink: 0;
    }
    .tutorial-header-title {
      display: flex;
      flex-direction: column;
      gap: 2px;
    }
    .tutorial-header-title h2 {
      margin: 0;
      font-size: 16px;
      font-weight: 700;
      color: var(--text);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .tutorial-header-subtitle {
      font-size: 11px;
      color: var(--text-muted);
    }
    .tutorial-tabs {
      display: flex;
      gap: 6px;
      padding: 10px 20px 8px;
      background: #111216;
      border-bottom: 1px solid var(--panel-border);
      flex-shrink: 0;
      overflow-x: auto;
    }
    .tutorial-tab-btn {
      background: transparent;
      border: 1px solid transparent;
      color: var(--text-muted);
      font-size: 12px;
      font-weight: 600;
      padding: 6px 14px;
      border-radius: 6px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: all 0.15s ease;
      white-space: nowrap;
    }
    .tutorial-tab-btn:hover {
      color: var(--text);
      background: rgba(255, 255, 255, 0.05);
    }
    .tutorial-tab-btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #3b82f6;
      box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
    }
    .tutorial-body {
      flex: 1;
      overflow-y: auto;
      padding: 20px;
      display: flex;
      flex-direction: column;
    }
    .tutorial-tab-pane {
      display: none;
      flex-direction: column;
      gap: 14px;
    }
    .tutorial-tab-pane.active {
      display: flex;
    }
    .tutorial-card {
      background: #15161c;
      border: 1px solid var(--panel-border);
      border-radius: 8px;
      padding: 14px 16px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      transition: border-color 0.15s ease;
    }
    .tutorial-card:hover {
      border-color: rgba(59, 130, 246, 0.4);
    }
    .tutorial-card-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
    }
    .tutorial-card-title {
      font-size: 13px;
      font-weight: 700;
      color: var(--text);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .tutorial-card-badge {
      font-size: 10px;
      padding: 2px 8px;
      border-radius: 12px;
      background: rgba(59, 130, 246, 0.15);
      color: #60a5fa;
      border: 1px solid rgba(59, 130, 246, 0.3);
      font-weight: 600;
      white-space: nowrap;
    }
    .tutorial-card-desc {
      font-size: 12px;
      line-height: 1.55;
      color: var(--text-muted);
    }
    .tutorial-card-desc b, .tutorial-card-desc strong {
      color: var(--text);
    }
    .tutorial-step-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .tutorial-step-item {
      display: flex;
      gap: 14px;
      background: #15161c;
      border: 1px solid var(--panel-border);
      border-radius: 8px;
      padding: 14px 16px;
      align-items: flex-start;
    }
    .tutorial-step-num {
      background: #2563eb;
      color: #ffffff;
      font-weight: 700;
      font-size: 12px;
      width: 26px;
      height: 26px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      margin-top: 1px;
    }
    .tutorial-step-content {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 4px;
    }
    .tutorial-step-title {
      font-size: 13px;
      font-weight: 700;
      color: var(--text);
    }
    .tutorial-step-desc {
      font-size: 12px;
      line-height: 1.55;
      color: var(--text-muted);
    }
    .tutorial-grid-2 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
      gap: 12px;
    }
    .tutorial-table {
      width: 100%;
      border-collapse: collapse;
      font-size: 12px;
    }
    .tutorial-table th, .tutorial-table td {
      padding: 8px 12px;
      border: 1px solid var(--panel-border);
      text-align: left;
    }
    .tutorial-table th {
      background: #14151a;
      color: var(--text);
      font-weight: 600;
    }
    .tutorial-table tr:nth-child(even) td {
      background: rgba(255, 255, 255, 0.02);
    }
    .tutorial-footer {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 12px 20px;
      background: #14151a;
      border-top: 1px solid var(--panel-border);
      flex-shrink: 0;
      gap: 12px;
    }
    .tutorial-startup-toggle {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 12px;
      color: var(--text-muted);
      cursor: pointer;
    }
    .tutorial-startup-toggle input[type="checkbox"] {
      cursor: pointer;
    }

    /* Light theme overrides for Tutorial */
    body.light-theme #tutorial-modal .tutorial-dialog {
      background: #ffffff;
      color: #1e293b;
      border-color: #d1d5db;
    }
    body.light-theme .tutorial-header,
    body.light-theme .tutorial-footer {
      background: #f8fafc;
      border-color: #e2e8f0;
    }
    body.light-theme .tutorial-tabs {
      background: #f1f5f9;
      border-color: #e2e8f0;
    }
    body.light-theme .tutorial-tab-btn {
      color: #64748b;
    }
    body.light-theme .tutorial-tab-btn:hover {
      color: #1e293b;
      background: rgba(0, 0, 0, 0.05);
    }
    body.light-theme .tutorial-tab-btn.active {
      background: #2563eb;
      color: #ffffff;
    }
    body.light-theme .tutorial-card,
    body.light-theme .tutorial-step-item {
      background: #f8fafc;
      border-color: #e2e8f0;
    }
    body.light-theme .tutorial-card-title,
    body.light-theme .tutorial-step-title,
    body.light-theme .tutorial-header-title h2 {
      color: #0f172a;
    }
    body.light-theme .tutorial-card-desc,
    body.light-theme .tutorial-step-desc,
    body.light-theme .tutorial-header-subtitle {
      color: #475569;
    }
    body.light-theme .tutorial-table th {
      background: #f1f5f9;
      color: #0f172a;
      border-color: #cbd5e1;
    }
    body.light-theme .tutorial-table td {
      border-color: #e2e8f0;
      color: #334155;
    }
    body.light-theme .tutorial-table tr:nth-child(even) td {
      background: #f8fafc;
    }

    /* ── Buy Me a Coffee Badge ──────────────────────────────────────────────── */
    .bmac-badge-link {
      display: inline-flex;
      align-items: center;
      line-height: 0;
      text-decoration: none;
      flex-shrink: 0;
      border-radius: 4px;
      overflow: hidden;
      transition: transform 0.15s ease, opacity 0.15s ease, box-shadow 0.15s ease;
    }
    .bmac-badge-link:hover {
      transform: translateY(-1px);
      opacity: 0.92;
      box-shadow: 0 2px 8px rgba(255, 221, 0, 0.4);
    }
    .bmac-badge-link img {
      height: 26px;
      display: block;
      border: 0;
    }
    @media (max-width: 1200px) {
      #top-bar .bmac-badge-link img {
        height: 22px;
      }
    }
    @media (max-width: 900px) {
      #top-bar .bmac-badge-link {
        display: none;
      }
    }