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

    /* ── Design tokens (Editorial Organicism) ────────────────────────── */
    :root {
      --surface-lowest:        #FFFFFF;
      --surface-low:           #F3F3F4;
      --surface:               #EEEEEE;
      --surface-high:          #E8E8E8;
      --surface-highest:       #E2E2E2;
      --surface-bg:            #F9F9F9;

      --on-surface:            #1A1C1C;
      --on-surface-variant:    #434840;

      --primary:               #476643;
      --primary-container:     #A5C89E;
      --on-primary-container:  #365433;

      --secondary-container:   #DEE9A3;
      --on-secondary-container:#606931;

      --outline:               #73796F;
      --outline-variant:       rgba(195, 200, 189, 0.15);

      --font:         "Plus Jakarta Sans", sans-serif;
      --radius-xl:    3rem;
      --radius-lg:    2rem;
      --radius-md:    1rem;
      --radius-full:  9999px;

      --spacing-2: 0.75rem;
      --spacing-4: 1.4rem;
      --spacing-6: 2rem;
      --spacing-8: 3rem;

      --panel-w:      23.5rem;    /* 22rem width + 1.5rem offset */

      --shadow-ambient:  0 20px 40px rgba(71, 102, 67, 0.06);
      --shadow-nav-top:  0 4px 24px rgba(71, 102, 67, 0.06);
      --shadow-panel:   -20px 0 40px rgba(71, 102, 67, 0.04);
    }

    /* ── Base ────────────────────────────────────────────────────────── */
    html, body {
      height: 100%;
      font-family: var(--font);
      font-size: 1rem;
      line-height: 1.6;
      background: var(--surface-bg);
      color: var(--on-surface);
      overflow: hidden;
      -webkit-font-smoothing: antialiased;
    }

    /* ── Material Symbols ────────────────────────────────────────────── */
    .material-symbols-outlined {
      font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
      line-height: 1;
      user-select: none;
    }

    /* ═══════════════════════════════════════════════════════════════════
       CANVAS AREA (Three.js viewport)
    ═══════════════════════════════════════════════════════════════════ */
    #canvas-container {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      z-index: 0;
      background: var(--surface-bg);
    }
    #canvas-container canvas {
      display: block;
      width: 100% !important;
      height: 100% !important;
    }

    /* ── Canvas grid pattern ─────────────────────────────────────────── */
    #canvas-container::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: radial-gradient(circle, rgba(115,121,111,0.13) 1px, transparent 1px);
      background-size: 32px 32px;
      pointer-events: none;
      z-index: 1;
    }

    /* ── Viewport overlay badges ─────────────────────────────────────── */
    #viewport-overlay {
      position: absolute;
      top: 1.5rem;
      left: 50%;
      transform: translateX(-50%);
      display: flex;
      justify-content: center;
      align-items: flex-start;
      z-index: 5;
      pointer-events: none;
    }
    .viewport-badge {
      display: flex;
      align-items: center;
      gap: 0.4rem;
      background: rgba(255,255,255,0.6);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255,255,255,0.4);
      border-radius: var(--radius-full);
      padding: 0.35rem 0.85rem;
      font-size: 0.65rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      color: var(--on-surface-variant);
    }

    /* ── Viewport Gizmos ─────────────────────────────────────────────── */
    #viewport-gizmos {
      position: absolute;
      top: 1.25rem;
      right: calc(16rem + 2.5rem);
      display: flex;
      flex-direction: row;
      gap: 0.75rem;
      z-index: 10;
    }

    .gizmo-btn {
      width: 2.5rem;
      height: 2.5rem;
      border-radius: var(--radius-full);
      background: var(--surface-lowest);
      box-shadow: var(--shadow-ambient);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      border: 1px solid var(--outline-variant);
      cursor: pointer;
      transition: background 0.2s, transform 0.15s;
    }

    .gizmo-btn:hover {
      background: var(--secondary-container);
      color: var(--on-secondary-container);
      border-color: transparent;
    }

    .gizmo-btn:active {
      transform: scale(0.95);
    }
    .viewport-dot {
      width: 7px; height: 7px;
      border-radius: 50%;
      background: #22c55e;
    }

    /* ── Hint overlay ────────────────────────────────────────────────── */
    #hint-overlay {
      position: absolute;
      top: 0;
      left: 0;
      bottom: 0;
      right: 0;
      z-index: 3;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 1.25rem;
      pointer-events: none;
      transition: opacity 0.6s ease;
    }
    #hint-overlay.hidden { opacity: 0; }
    .hint-glyph {
      font-size: 72px;
      line-height: 1;
      opacity: 0.08;
    }
    .hint-title {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--on-surface-variant);
      letter-spacing: -0.02em;
      opacity: 0.5;
    }
    .hint-sub {
      font-size: 0.875rem;
      color: var(--on-surface-variant);
      opacity: 0.35;
    }

    /* ═══════════════════════════════════════════════════════════════════
       EDITOR UI PANELS
    ═══════════════════════════════════════════════════════════════════ */
    #editor-ui {
      position: fixed;
      inset: 0;
      z-index: 50;
      pointer-events: none;
    }

    .editor-panel {
      pointer-events: auto;
      position: absolute;
      display: flex;
      flex-direction: column;
      gap: 0.75rem;
    }

    /* Left Sidebar */
    #panel-left {
      top: 1.25rem;
      left: 1.25rem;
      width: 16rem;
      max-height: calc(100vh - 3rem);
      overflow-y: auto;
      scrollbar-width: none;
    }
    #panel-left::-webkit-scrollbar { display: none; }

    /* Right Sidebar */
    #panel-right {
      top: 1.25rem;
      right: 1.25rem;
      width: 16rem;
      max-height: calc(100vh - 3rem);
      overflow-y: auto;
      scrollbar-width: none;
    }
    #panel-right::-webkit-scrollbar { display: none; }

    /* Footer area */
    #panel-bottom-fixed {
      bottom: 1.25rem;
      left: 1.25rem;
      align-items: flex-start;
    }

    .stats-card {
      min-width: unset;
      justify-content: center;
      padding: 0.6rem 1rem;
    }

    /* ── Panel header ────────────────────────────────────────────────── */
    .panel-header {
      background: transparent;
      padding: 0.25rem 0.5rem 0.5rem 0.5rem;
      gap: 0.1rem;
    }
    .panel-eyebrow {
      font-size: 0.55rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.15em;
      color: var(--outline);
      margin-bottom: 0.2rem;
    }
    .panel-title {
      font-size: 1.25rem;
      font-weight: 800;
      letter-spacing: -0.03em;
      color: var(--primary);
      line-height: 1.15;
    }
    .panel-title span { color: var(--secondary-container); }
    .panel-subtitle {
      font-size: 0.65rem;
      color: var(--on-surface-variant);
      margin-top: 4px;
      font-weight: 600;
      letter-spacing: 0.04em;
      text-transform: uppercase;
    }

    /* ── Section card ────────────────────────────────────────────────── */
    .card {
      background: rgba(255, 255, 255, 0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: var(--shadow-ambient);
      border-radius: var(--radius-lg);
      padding: 0.85rem 1rem;
      display: flex;
      flex-direction: column;
      gap: 0.75rem;
    }
    .card-label {
      font-size: 0.6rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--on-surface-variant);
    }

    /* ── Drop zone ───────────────────────────────────────────────────── */
    .drop-zone {
      position: relative;
      display: flex;
      align-items: center;
      gap: 0.75rem;
      padding: 0.75rem 1rem;
      background: var(--surface);
      border-radius: var(--radius-lg);
      cursor: pointer;
      transition: background 0.25s, transform 0.15s;
      min-height: 48px;
    }
    .drop-zone.dragging,
    .drop-zone:hover { background: var(--secondary-container); transform: scale(1.008); }
    .drop-zone.loaded { background: var(--primary-container); }

    .drop-zone input[type="file"] {
      position: absolute;
      inset: 0;
      opacity: 0;
      cursor: pointer;
      width: 100%;
      height: 100%;
    }
    .drop-icon-wrap {
      width: 28px; height: 28px;
      border-radius: var(--radius-full);
      background: rgba(255,255,255,0.65);
      display: flex; align-items: center; justify-content: center;
      flex-shrink: 0;
    }
    .drop-icon-wrap .material-symbols-outlined { font-size: 16px; color: var(--primary); }
    .drop-zone.loaded .drop-icon-wrap { background: rgba(255,255,255,0.5); }
    .drop-info { flex: 1; overflow: hidden; }
    .drop-name {
      font-size: 0.75rem;
      font-weight: 600;
      color: var(--on-surface);
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .drop-zone.loaded .drop-name { color: var(--on-primary-container); }
    .drop-hint {
      font-size: 0.55rem;
      color: var(--on-surface-variant);
      margin-top: 1px;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      font-weight: 600;
    }
    .drop-zone.loaded .drop-hint { color: var(--on-primary-container); opacity: 0.7; }

    /* ── Palette swatches ────────────────────────────────────────────── */
    #palette-swatches {
      display: flex;
      flex-wrap: wrap;
      gap: 4px;
      min-height: 0;
      max-height: 100px;
      overflow-y: auto;
    }
    #palette-swatches::-webkit-scrollbar { display: none; }
    #palette-swatches { scrollbar-width: none; }
    #palette-swatches.has-colors { min-height: 18px; }
    .swatch {
      width: 18px; height: 18px;
      border-radius: var(--radius-full);
      flex-shrink: 0;
      cursor: pointer;
      transition: transform 0.15s, box-shadow 0.15s;
    }
    .swatch:hover {
      transform: scale(1.15);
    }
    .swatch.active {
      transform: scale(1.2);
      box-shadow: 0 0 0 2px var(--surface-low), 0 0 0 4px var(--primary);
      z-index: 2;
    }
    #palette-name {
      font-size: 0.65rem;
      color: var(--on-surface-variant);
      text-transform: uppercase;
      letter-spacing: 0.07em;
      font-weight: 600;
    }

    /* ── Paint Toggle ────────────────────────────────────────────────── */
    .toggle-paint {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      font-size: 0.7rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      color: var(--primary);
      cursor: pointer;
      user-select: none;
      padding: 4px 8px;
      border-radius: var(--radius-full);
      transition: background 0.2s;
    }
    .toggle-paint:hover {
      background: var(--surface-high);
    }
    .toggle-paint input {
      display: none;
    }
    .toggle-paint:has(input:checked) {
      background: var(--secondary-container);
      color: var(--on-secondary-container);
    }

    /* ── Resolution slider ───────────────────────────────────────────── */
    .slider-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .slider-desc {
      font-size: 0.75rem;
      color: var(--on-surface-variant);
    }
    .slider-badge {
      font-size: 0.75rem;
      font-weight: 700;
      color: var(--on-secondary-container);
      background: var(--secondary-container);
      border-radius: var(--radius-full);
      padding: 2px 8px;
      min-width: 36px;
      text-align: center;
    }
    .slider-wrap {
      padding: 6px 0 2px;
      position: relative;
    }
    input[type="range"] {
      -webkit-appearance: none;
      appearance: none;
      width: 100%;
      height: 7px;
      border-radius: var(--radius-full);
      outline: none;
      cursor: pointer;
      background: linear-gradient(
        to right,
        var(--primary) var(--pct, 11%),
        var(--surface) var(--pct, 11%)
      );
    }
    input[type="range"]::-webkit-slider-thumb {
      -webkit-appearance: none;
      width: 22px; height: 22px;
      border-radius: 50%;
      background: #ffffff;
      box-shadow: 0 2px 10px rgba(71,102,67,0.15);
      border: 1.5px solid rgba(195,200,189,0.4);
      cursor: pointer;
      transition: transform 0.1s;
    }
    input[type="range"]:active::-webkit-slider-thumb { transform: scale(1.18); }
    .slider-ticks {
      display: flex;
      justify-content: space-between;
      padding: 6px 2px 0;
    }
    .slider-ticks span {
      font-size: 0.65rem;
      color: var(--on-surface-variant);
      font-weight: 600;
    }

    /* ── Progress ────────────────────────────────────────────────────── */
    .progress-track {
      height: 5px;
      background: var(--surface);
      border-radius: var(--radius-full);
      overflow: hidden;
    }
    #progress-fill {
      height: 100%;
      width: 0%;
      background: var(--primary);
      border-radius: var(--radius-full);
      transition: width 0.3s ease-out;
    }

    /* ── Status row ──────────────────────────────────────────────────── */
    .status-row {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      min-height: 24px;
    }
    .status-dot {
      width: 6px; height: 6px;
      border-radius: 50%;
      flex-shrink: 0;
      background: var(--surface-highest);
      transition: background 0.3s;
    }
    .status-dot.ok     { background: var(--primary); }
    .status-dot.error  { background: #d9534f; }
    .status-dot.info   { background: var(--primary-container); }
    .status-dot.pulse  {
      background: var(--primary-container);
      animation: pulse 1.5s ease-in-out infinite;
    }
    @keyframes pulse {
      0%, 100% { transform: scale(1); opacity: 1; }
      50%       { transform: scale(1.3); opacity: 0.5; }
    }
    #status-text {
      font-size: 0.75rem;
      color: var(--on-surface-variant);
      flex: 1;
      min-width: 0;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    #status-text.ok    { color: var(--primary); }
    #status-text.error { color: #d9534f; }

    /* ── Action buttons ──────────────────────────────────────────────── */
    .actions { display: flex; flex-direction: column; gap: 0.5rem; }

    .btn {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      border: none;
      border-radius: var(--radius-full);
      min-height: 2.75rem;
      font-family: var(--font);
      font-size: 0.85rem;
      font-weight: 700;
      cursor: pointer;
      transition: opacity 0.2s, transform 0.12s, background 0.2s;
    }
    .btn:disabled { opacity: 0.38; cursor: not-allowed; }
    .btn:active:not(:disabled) { transform: scale(0.98); }

    .btn-primary {
      background: var(--primary-container);
      color: var(--on-primary-container);
    }
    .btn-primary:hover:not(:disabled) { background: #96b98f; }

    .btn-secondary {
      background: var(--surface-high);
      color: var(--on-surface);
    }
    .btn-secondary:hover:not(:disabled) { background: var(--surface-highest); }

    /* ── Bottom Quick Stats ──────────────────────────────────────────── */
    #panel-bottom-center {
      bottom: 2rem;
      left: 50%;
      transform: translateX(-50%);
      align-items: center;
    }

    .quick-stats-bar {
      display: flex;
      align-items: center;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: var(--shadow-ambient);
      border-radius: var(--radius-full);
      padding: 0.35rem 1.5rem 0.35rem 0.4rem;
      gap: 1.5rem;
    }

    .qs-item {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }

    .qs-text {
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    .qs-label {
      font-size: 0.55rem;
      font-weight: 700;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--on-surface-variant);
      margin-bottom: 2px;
      line-height: 1;
    }

    .qs-val {
      font-size: 0.85rem;
      font-weight: 700;
      color: var(--on-surface);
      line-height: 1.1;
    }

    .qs-divider {
      width: 1px;
      height: 24px;
      background: var(--outline-variant);
    }

    .qs-highlight {
      background: rgba(222, 233, 163, 0.5);
      padding: 0.4rem 1rem 0.4rem 0.75rem;
      border-radius: var(--radius-full);
      margin: 0;
    }
    
    .qs-highlight .qs-label {
      color: rgba(96,105,49,0.7);
    }

    .qs-highlight .qs-val {
      color: var(--on-secondary-container);
    }

    .qs-icon {
      font-size: 18px!important;
      color: var(--on-secondary-container);
    }

    #export-size-display { /* dynamic, updated by JS event */ }

    /* ── Panel footer ────────────────────────────────────────────────── */
    .panel-footer {
      background: rgba(255, 255, 255, 0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: var(--shadow-ambient);
      border-radius: var(--radius-full);
      padding: 0.4rem 1rem;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 1rem;
    }
    .footer-text {
      font-size: 0.55rem;
      color: var(--on-surface-variant);
      text-transform: uppercase;
      letter-spacing: 0.05em;
      font-weight: 600;
      opacity: 0.6;
    }
    .footer-badge {
      font-size: 0.55rem;
      font-weight: 800;
      color: var(--on-surface-variant);
      background: var(--surface-high);
      border-radius: var(--radius-full);
      padding: 2px 8px;
      letter-spacing: 0.05em;
    }