:root {
    --bg-app: #0f1117;
    --bg-sidebar: #161b27;
    --bg-card: #1e2535;
    --bg-card-hover: #252d40;
    --bg-canvas: #f0f2f7;
    --bg-toolbar: #161b27;
    --bg-modal: #1c2333;
    --bg-input: #0f1117;

    --text-primary: #e8ecf4;
    --text-secondary: #8a95aa;
    --text-muted: #5a647a;

    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --accent-light: rgba(59,130,246,0.12);
    --accent-glow: rgba(59,130,246,0.25);

    --supply: #3b82f6;
    --return-color: #f97316;
    --fresh: #22c55e;
    --exhaust: #94a3b8;

    --border: rgba(255,255,255,0.07);
    --border-input: rgba(255,255,255,0.1);
    --border-focus: rgba(59,130,246,0.5);

    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    /* Refined Graphite: layered depth with a crisp top-light edge */
    --edge-light: inset 0 1px 0 rgba(255,255,255,0.06);
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.45), var(--edge-light);
    --shadow-md: 0 8px 24px rgba(0,0,0,0.48), var(--edge-light);
    --shadow-lg: 0 18px 44px rgba(0,0,0,0.58), var(--edge-light);
    --border-strong: rgba(255,255,255,0.12);

    /* Signature accent extras (base hue tracks the default 'blue' accent = #3b82f6) */
    --accent-soft:  rgba(59,130,246,0.12);
    --accent-edge:  rgba(59,130,246,0.45);
    --accent-line:  linear-gradient(90deg, #3b82f6, #60a5fa);

    --brand-primary:   #3b82f6;
    --brand-secondary: #60a5fa;
    --brand-accent:    #2563eb;

    --surface-hover: #252b38;

    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, 'Apple Color Emoji', 'Segoe UI Emoji', 'Noto Color Emoji', sans-serif;
    --font-mono: 'JetBrains Mono','SF Mono','SFMono-Regular',ui-monospace,Menlo,Consolas,monospace;
    --spring: cubic-bezier(.2,.8,.2,1);
    --transition: 0.15s ease;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; }
  /* Keyboard navigation focus ring — only fires on keyboard, not mouse */
  :focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
  /* Elements with custom focus styles suppress the default ring */
  .prop-input:focus-visible, .duct-width-select:focus-visible,
  .api-key-input:focus-visible, .unit-search:focus-visible,
  .chat-input:focus-visible { outline: none; }
  body { font-family: var(--font); background: var(--bg-app); color: var(--text-primary); height: 100vh; overflow: hidden; }

  /* ── Shell ── */
  .app { display: flex; flex-direction: column; height: 100vh; }

  /* ── Topbar ── */
  .topbar {
    display: flex; align-items: center; gap: var(--sp-2_5);
    padding: 0 var(--sp-5); height: 52px;
    background: var(--bg-toolbar);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0; position: relative; z-index: 30;
  }
  .logo { display: flex; align-items: center; gap: 9px; font-size: var(--text-lg); font-weight: 600; color: var(--text-primary); letter-spacing: -0.01em; }
  .logo-mark {
    display: block; flex-shrink: 0; width: 26px; height: 26px;
    border-radius: 7px; box-shadow: 0 1px 4px rgba(0,0,0,0.28);
  }
  .logo-word {
    font-size: var(--text-xl); font-weight: 700; letter-spacing: -0.035em;
    color: var(--text-primary); white-space: nowrap;
  }
  .logo-word > span { color: var(--accent); }
  .logo-icon {
    width: 30px; height: 30px; border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--accent), var(--brand-secondary));
    display: flex; align-items: center; justify-content: center;
    font-size: var(--text-xl); color: #fff; box-shadow: 0 2px 8px var(--accent-glow);
  }
  .topbar-badge {
    font-size: var(--text-2xs); font-weight: 500;
    background: rgba(34,197,94,0.12); color: #22c55e;
    border: 1px solid rgba(34,197,94,0.2);
    padding: var(--sp-0_5) var(--sp-2); border-radius: 20px; letter-spacing: 0.02em;
    flex-shrink: 0; white-space: nowrap;
  }
  .topbar-spacer { flex: 1; }
  /* Project context chip: name + inline save-state read as a single unit. */
  .topbar-project-chip {
    display: inline-flex; align-items: center; gap: var(--sp-1);
    min-width: 0; flex-shrink: 0;
  }
  .topbar-project {
    font-size: var(--text-xs); color: var(--text-muted); cursor: pointer;
    max-width: 160px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    padding: var(--sp-0_5) var(--sp-1_5); border-radius: 4px;
    /* Hold the (≤160px, ellipsised) width instead of collapsing. The overflow:hidden
       otherwise lets this flex item shrink to ~0 when the topbar is over-stuffed, so
       the name gets crushed to a letter or two against the logo ("stacked on title"). */
    flex-shrink: 0;
  }
  .topbar-project:hover { color: var(--text-secondary); background: var(--surface-hover); }
  .topbar-save-status {
    font-size: var(--text-2xs); color: var(--text-muted); white-space: nowrap;
    display: inline-flex; align-items: center; gap: var(--sp-1); padding: var(--sp-0_5) var(--sp-1);
    user-select: none;
  }
  .topbar-save-status.is-dirty { color: #f59e0b; }
  .topbar-save-status.is-saved { color: var(--text-muted); }
  .topbar-actions { display: flex; gap: var(--sp-1_5); }

  /* ── Floor (storey) tabs ── */
  .floor-tabs { display: flex; align-items: center; gap: var(--sp-1); margin-left: var(--sp-2); }
  .floor-tab {
    display: inline-flex; align-items: center; gap: 5px;
    font-size: var(--text-xs); font-weight: 500; color: var(--text-muted);
    background: transparent; border: 1px solid var(--border);
    padding: 3px 9px; border-radius: 6px; cursor: pointer; white-space: nowrap;
    max-width: 140px; overflow: hidden; text-overflow: ellipsis;
  }
  .floor-tab:hover { color: var(--text-secondary); background: var(--surface-hover); }
  .floor-tab.active {
    color: #fff; background: var(--accent, #3b82f6);
    border-color: var(--accent, #3b82f6);
  }
  .floor-peer-dot {
    width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0;
    box-shadow: 0 0 0 1px rgba(0,0,0,0.25);
  }
  .floor-tab-add {
    display: inline-flex; align-items: center; justify-content: center;
    width: 24px; height: 24px; border-radius: 6px; cursor: pointer;
    color: var(--text-muted); background: transparent; border: 1px solid var(--border);
    font-size: var(--text-base);
  }
  .floor-tab-add:hover { color: var(--text-secondary); background: var(--surface-hover); }

  /* ── Toolbar ── */
  .toolbar {
    display: flex; flex-direction: column;
    background: var(--bg-sidebar);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
  }
  .toolbar-row {
    display: flex; align-items: center; gap: 3px;
    padding: 0 var(--sp-2_5); height: 42px; flex-shrink: 0;
  }
  .toolbar-row:first-child { border-bottom: 1px solid var(--border); }
  .toolbar-rows { display: contents; }
  .toolbar-mobile-trigger { display: none; }
  /* Two-class selector so it outranks the later `.btn-icon { display:inline-flex }`
     base rule (equal single-class specificity would lose on source order, leaking
     the kebab onto the desktop bar). The mobile show-rule is bumped to match. */
  .topbar .topbar-menu-trigger { display: none; }
  .tool-divider { width: 1px; height: 20px; background: var(--border); margin: 0 5px; flex-shrink: 0; }
  .tool-label { font-size: var(--text-2xs); font-weight: 500; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.06em; margin-right: var(--sp-1); flex-shrink: 0; }

  /* ── Buttons ── */
  .btn {
    display: inline-flex; align-items: center; gap: 5px;
    padding: 5px var(--sp-2_5); font-size: var(--text-sm); font-weight: 500;
    border: 1px solid var(--border); border-radius: var(--radius-md);
    background: transparent; color: var(--text-secondary);
    cursor: pointer; transition: all var(--transition);
    white-space: nowrap; flex-shrink: 0;
  }
  .btn i { font-size: var(--text-md); }
  .btn:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); border-color: rgba(255,255,255,0.14); }
  .btn.active { background: var(--accent-light); color: var(--accent); border-color: var(--border-focus); }
  /* Duct tool color stripes — driven by CSS vars so they update when user changes duct colours */
  #btn-supply  { box-shadow: inset 3px 0 0 var(--supply); }
  #btn-return  { box-shadow: inset 3px 0 0 var(--return-color); }
  #btn-fresh   { box-shadow: inset 3px 0 0 var(--fresh); }
  #btn-exhaust { box-shadow: inset 3px 0 0 var(--exhaust); }
  /* Color-aware active states for duct tools */
  #btn-supply.active  { background: rgba(59,130,246,0.15); color: var(--supply); border-color: rgba(59,130,246,0.4); box-shadow: inset 3px 0 0 var(--supply); }
  #btn-return.active  { background: rgba(249,115,22,0.15);  color: var(--return-color); border-color: rgba(249,115,22,0.4);  box-shadow: inset 3px 0 0 var(--return-color); }
  #btn-fresh.active   { background: rgba(34,197,94,0.15);   color: var(--fresh); border-color: rgba(34,197,94,0.4);   box-shadow: inset 3px 0 0 var(--fresh); }
  #btn-exhaust.active { background: rgba(245,158,11,0.15);  color: var(--exhaust); border-color: rgba(245,158,11,0.4);  box-shadow: inset 3px 0 0 var(--exhaust); }
  .btn:disabled { opacity: 0.35; cursor: not-allowed; }
  .btn:disabled:hover { background: transparent; color: var(--text-secondary); border-color: var(--border); }
  .btn:active:not(:disabled), .btn-ghost:active { transform: scale(0.95); }
  .btn-primary {
    width: 100%; padding: var(--sp-2) var(--sp-3); font-size: var(--text-sm); font-weight: 600;
    background: var(--accent); color: #fff; border: none; border-radius: var(--radius-md);
    cursor: pointer; display: flex; align-items: center; justify-content: center; gap: var(--sp-1_5);
    transition: all var(--transition); letter-spacing: 0.01em;
  }
  .btn-primary:hover { background: var(--accent-hover); box-shadow: 0 4px 12px var(--accent-glow); }
  .btn-primary:active { transform: scale(0.95); }
  .btn-secondary {
    width: 100%; padding: 7px var(--sp-3); font-size: var(--text-sm); font-weight: 500;
    background: rgba(255,255,255,0.05); color: var(--text-secondary);
    border: 1px solid var(--border); border-radius: var(--radius-md);
    cursor: pointer; margin-top: var(--sp-1_5);
    display: flex; align-items: center; justify-content: center; gap: var(--sp-1_5);
    transition: all var(--transition);
  }
  .btn-secondary:hover { background: rgba(255,255,255,0.09); color: var(--text-primary); }
  .btn-icon {
    width: 28px; height: 28px; padding: 0;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: var(--radius-md); background: transparent;
    border: 1px solid var(--border); color: var(--text-secondary);
    cursor: pointer; transition: all var(--transition); font-size: var(--text-md);
  }
  .btn-icon:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); }
  .btn-icon:active:not(:disabled) { transform: scale(0.9); }
  .btn-icon:disabled { opacity: 0.3; cursor: not-allowed; }
  .btn-danger { border-color: rgba(239,68,68,0.3); color: #f87171; }
  .btn-danger:hover { background: rgba(239,68,68,0.1); border-color: rgba(239,68,68,0.5); color: #f87171; }
  .btn-ghost {
    display: inline-flex; align-items: center; gap: 5px;
    padding: 5px var(--sp-2_5); font-size: var(--text-sm); font-weight: 500;
    border: none; border-radius: var(--radius-md);
    background: transparent; color: var(--text-secondary);
    cursor: pointer; transition: all var(--transition);
    white-space: nowrap;
  }
  .btn-ghost:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); }
  .btn-ai {
    background: linear-gradient(135deg, rgba(139,92,246,0.15), rgba(59,130,246,0.15));
    border-color: rgba(139,92,246,0.3); color: #a78bfa;
  }
  .btn-ai:hover { background: linear-gradient(135deg, rgba(139,92,246,0.25), rgba(59,130,246,0.25)); border-color: rgba(139,92,246,0.5); color: #c4b5fd; }
  .btn-ai.loading { animation: pulse-ai 1.2s ease infinite; }
  @keyframes pulse-ai { 0%,100% { opacity: 1; } 50% { opacity: 0.5; } }

  /* ── Color Swatches ── */
  .color-swatch {
    width: 18px; height: 18px; border-radius: 4px;
    border: 2px solid transparent; cursor: pointer;
    transition: all var(--transition); flex-shrink: 0;
  }
  .color-swatch:hover { transform: scale(1.2); }
  .color-swatch.selected { border-color: #fff; box-shadow: 0 0 0 1px rgba(255,255,255,0.3); transform: scale(1.15); }

  /* ── Width Select ── */
  .duct-width-select {
    font-size: var(--text-xs); padding: var(--sp-1) var(--sp-1_5);
    background: var(--bg-input); color: var(--text-primary);
    border: 1px solid var(--border-input); border-radius: var(--radius-sm);
    cursor: pointer; width: 100px;
  }
  .duct-width-select:focus { outline: none; border-color: var(--border-focus); }

  /* ── Layout ── */
  .main { display: flex; flex: 1; overflow: hidden; }

  /* ── Sidebar ── */
  .sidebar {
    width: 288px; flex-shrink: 0;
    background: var(--bg-sidebar); border-right: 1px solid var(--border);
    display: flex; flex-direction: column; overflow: hidden;
    transition: width 0.22s ease;
  }
  .sidebar.collapsed { width: 52px; }
  .sidebar.collapsed .sidebar-tabs { flex-direction: column; border-bottom: none; padding: var(--sp-1); gap: 3px; }
  .sidebar.collapsed .s-tab-label { display: none; }
  .sidebar.collapsed .sidebar-pane { display: none !important; }
  .sidebar.collapsed .sidebar-hint { display: none; }
  .sidebar.collapsed .sidebar-tab { padding: 11px 0; border-bottom: none; margin-bottom: 0; border-radius: var(--radius-md); }
  .sidebar.collapsed .sidebar-tab.active { background: var(--accent-light); }
  .sidebar.collapsed .sidebar-tab i { font-size: 19px; }
  .sidebar.collapsed .sidebar-collapse-btn { width: auto; border-left: none; border-top: 1px solid var(--border); margin: var(--sp-1) var(--sp-1) 0; padding: 9px 0; border-radius: var(--radius-md); }
  .sidebar-section { padding: var(--sp-2) var(--sp-2_5); border-bottom: 1px solid var(--border); }
  .section-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 7px; }
  .section-title { font-size: var(--text-xs); font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; }

  /* ── Form utilities (extracted from repeated inline styles) ──
     .nd-field-label: the uppercase "eyebrow" label above a control.
     .nd-check: accent-coloured checkbox/radio at the standard 16px box. */
  .nd-field-label { display: block; font-size: var(--text-xs); font-weight: 700; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: var(--sp-1_5); }
  .nd-check { accent-color: var(--accent); width: 16px; height: 16px; }

  /* ── Layers Panel ── */
  .layers-list { display:flex; flex-direction:column; gap:var(--sp-px); }
  .layer-row {
    display:flex; align-items:center; gap:var(--sp-1_5);
    padding:var(--sp-1_5) var(--sp-2); border-radius:var(--radius-md);
    cursor:pointer; border:1px solid transparent;
    transition:background var(--transition), border-color var(--transition);
    user-select:none;
  }
  .layer-row:hover { background:var(--bg-card-hover); }
  .layer-row.layer-active { background:rgba(59,130,246,0.1); border-color:rgba(59,130,246,0.25); }
  .layer-row.layer-hidden .layer-name { opacity:0.38; text-decoration:line-through; }
  .layer-row.layer-locked .layer-name { opacity:0.55; font-style:italic; }
  .layer-vis-btn, .layer-lock-btn {
    background:none; border:none; padding:0;
    width:24px; height:24px; display:flex; align-items:center; justify-content:center;
    cursor:pointer; border-radius:5px; color:var(--text-muted); font-size:var(--text-base); flex-shrink:0;
    transition:color var(--transition), background var(--transition);
  }
  .layer-vis-btn:hover, .layer-lock-btn:hover { color:var(--text-primary); background:rgba(255,255,255,0.07); }
  .layer-dot { width:10px; height:10px; border-radius:2px; flex-shrink:0; }
  .layer-name { font-size:var(--text-base); font-weight:500; color:var(--text-primary); flex:1; line-height:1.1; transition:opacity var(--transition); }
  /* Supply leg sub-rows */
  #legLayersList { margin-top:var(--sp-0_5); padding-top:var(--sp-0_5); border-top:1px solid var(--border); }
  #legLayersList:empty { display:none; }
  .leg-layer-row { cursor:default; padding-left:var(--sp-2_5); }
  .leg-layer-row:hover { background:var(--bg-card-hover); }
  .layer-active-pip { width:5px; height:5px; border-radius:50%; background:var(--accent); flex-shrink:0; }

  /* ── Duct List ── */
  .duct-list-empty {
    font-size: var(--text-xs); color: var(--text-muted); padding: var(--sp-2_5); text-align: center;
    background: rgba(255,255,255,0.02); border-radius: var(--radius-md);
    border: 1px dashed var(--border); line-height: 1.5;
  }
  .duct-item {
    display: flex; align-items: center; gap: var(--sp-2);
    padding: var(--sp-2) var(--sp-2_5); border-radius: var(--radius-md);
    border: 1px solid transparent; margin-bottom: var(--sp-1); font-size: var(--text-sm);
    cursor: pointer; transition: all var(--transition);
  }
  .duct-item:hover { background: rgba(255,255,255,0.04); border-color: var(--border); }
  .duct-item.selected { background: var(--accent-light); border-color: rgba(59,130,246,0.3); }
  .duct-dot { width: 8px; height: 8px; border-radius: 2px; flex-shrink: 0; }
  .duct-label { flex: 1; color: var(--text-primary); font-weight: 500; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .duct-type-tag { font-size: 9px; font-weight: 600; text-transform: uppercase; padding: var(--sp-px) 5px; border-radius: 3px; background: rgba(255,255,255,0.06); color: var(--text-muted); letter-spacing: 0.04em; flex-shrink: 0; }

  /* ── Legend ── */
  .legend { display: flex; flex-direction: column; gap: 5px; margin-top: var(--sp-2_5); }
  .legend-row { display: flex; align-items: center; gap: 7px; font-size: var(--text-xs); color: var(--text-secondary); }
  .legend-line { width: 20px; height: 3px; border-radius: 2px; flex-shrink: 0; }
  .legend-dashed { width: 20px; height: 3px; flex-shrink: 0; background: repeating-linear-gradient(90deg, var(--return-color) 0px, var(--return-color) 5px, transparent 5px, transparent 8px); }

  /* ── Form elements ── */
  .prop-row { display: flex; align-items: center; gap: var(--sp-2); margin-bottom: 7px; }
  .prop-label { font-size: var(--text-sm); color: var(--text-secondary); width: 78px; flex-shrink: 0; }
  .prop-input {
    flex: 1; font-size: var(--text-sm); padding: var(--sp-1_5) 9px;
    background: var(--bg-input); color: var(--text-primary);
    border: 1px solid var(--border-input); border-radius: var(--radius-sm);
    transition: border-color var(--transition);
  }
  .prop-input:focus { outline: none; border-color: var(--border-focus); background: rgba(59,130,246,0.04); }
  select.prop-input { cursor: pointer; color-scheme: dark; }
  select.prop-input option { background: var(--bg-input); color: var(--text-primary); }
  .props-card { background: var(--bg-card); border-radius: var(--radius-md); padding: var(--sp-2_5); border: 1px solid var(--border); }

  /* ── Rooms panel ── */
  .room-chip {
    display: inline-flex; align-items: center; gap: 5px;
    font-size: var(--text-2xs); padding: 3px var(--sp-2); border-radius: 12px;
    border: 1px solid var(--border); background: var(--bg-card);
    color: var(--text-secondary); margin: var(--sp-0_5); cursor: pointer;
  }
  .room-chip-dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; }

  /* ── Brand Cards ── */
  .brand-card { padding: 9px var(--sp-2_5); border-radius: var(--radius-md); border: 1px solid var(--border); margin-bottom: var(--sp-1_5); background: var(--bg-card); transition: all var(--transition); }
  .brand-card:hover { background: var(--bg-card-hover); border-color: rgba(255,255,255,0.12); }
  .brand-card-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 3px; }
  .brand-name { font-size: var(--text-sm); font-weight: 600; color: var(--text-primary); }
  .brand-country { font-size: var(--text-2xs); color: var(--text-muted); }
  .brand-note { font-size: var(--text-2xs); color: var(--text-secondary); line-height: 1.4; }
  .brand-badge { font-size: 9px; font-weight: 600; padding: var(--sp-0_5) 7px; border-radius: 10px; text-transform: uppercase; letter-spacing: 0.05em; display: inline-block; margin-top: 5px; }
  .brand-badge.premium { background: rgba(168,85,247,0.15); color: #c084fc; border: 1px solid rgba(168,85,247,0.2); }
  .brand-badge.mid { background: rgba(59,130,246,0.12); color: #60a5fa; border: 1px solid rgba(59,130,246,0.2); }
  .brand-badge.budget { background: rgba(34,197,94,0.1); color: #4ade80; border: 1px solid rgba(34,197,94,0.2); }

  /* ── Canvas ── */
  .canvas-area {
    flex: 1; position: relative; overflow: hidden;
    background: var(--bg-canvas);
    /* Grid is now drawn in world space on the canvas (drawGrid() in app.js) so it
       pans/zooms with content and stays aligned to the snap grid. The old static
       CSS background-grid only matched at zoom=1, pan=0 and has been removed. */
  }
  canvas { position: absolute; top: 0; left: 0; }

  /* ── Upload overlay ── */
  .upload-overlay {
    position: absolute; inset: 0; display: flex;
    flex-direction: column; align-items: center; justify-content: center; gap: var(--sp-4);
    background: rgba(240,242,247,0.94); backdrop-filter: blur(4px); z-index: 10;
  }
  .upload-box {
    border: 2px dashed rgba(100,116,139,0.4); border-radius: var(--radius-xl);
    padding: var(--sp-12) var(--sp-16); text-align: center; cursor: pointer;
    background: #fff; transition: all 0.2s; box-shadow: var(--shadow-md);
  }
  .upload-box:hover { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-glow), var(--shadow-md); }
  .upload-box.dragging { border-color: var(--accent); background: #f0f7ff; }
  /* Two upload choices side by side — AI (primary) vs manual (secondary). */
  .upload-choice-row { display: flex; gap: var(--sp-4); align-items: stretch; justify-content: center; flex-wrap: wrap; width: min(680px, 90vw); }
  .upload-choice-row .upload-box { flex: 1 1 240px; padding: var(--sp-9) var(--sp-7); position: relative; display: flex; flex-direction: column; justify-content: center; }
  .upload-choice-row .upload-title { line-height: 1.3; }
  .upload-choice-row .upload-sub { line-height: 1.4; max-width: 26ch; margin: 0 auto; }
  .upload-choice-row .upload-hint { line-height: 1.4; }
  .upload-box--primary { border-style: solid; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow), var(--shadow-md); }
  .upload-box--secondary { background: #fbfcfe; }
  .upload-box--secondary .upload-icon { background: rgba(100,116,139,0.12); }
  .upload-box--secondary .upload-icon i { color: #64748b; }
  .upload-badge { position: absolute; top: -10px; left: 50%; transform: translateX(-50%); background: var(--accent); color: #fff; font-size: 10px; font-weight: 700; letter-spacing: .04em; text-transform: uppercase; padding: 3px 9px; border-radius: 999px; white-space: nowrap; box-shadow: var(--shadow-sm); }
  .upload-icon { width: 56px; height: 56px; border-radius: var(--radius-lg); background: var(--accent-light); display: flex; align-items: center; justify-content: center; margin: 0 auto var(--sp-3_5); }
  .upload-icon i { font-size: 28px; color: var(--accent); }
  .upload-title { font-size: var(--text-xl); font-weight: 600; color: #1e293b; margin-bottom: var(--sp-1); }
  .upload-sub { font-size: var(--text-base); color: #64748b; }
  .upload-hint { font-size: var(--text-xs); color: #94a3b8; margin-top: var(--sp-2); }
  .upload-alt { display: flex; align-items: center; gap: var(--sp-2_5); color: #94a3b8; font-size: var(--text-sm); }
  .upload-alt::before, .upload-alt::after { content: ''; flex: 1; height: 1px; background: rgba(100,116,139,0.2); display: block; width: 60px; }

  /* ── AI Status Overlay ── */
  .ai-status-overlay {
    display: flex; position: absolute; inset: 0;
    align-items: center; justify-content: center;
    background: rgba(10,13,20,0.38);
    backdrop-filter: blur(2px);
    z-index: 20;
    opacity: 0; visibility: hidden; pointer-events: none;
    transition: opacity 0.2s ease, visibility 0.2s ease;
  }
  .ai-status-overlay.active { opacity: 1; visibility: visible; pointer-events: auto; }
  .ai-status-card {
    background: var(--bg-card);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-xl);
    padding: var(--sp-8) var(--sp-12);
    display: flex; flex-direction: column; align-items: center; gap: var(--sp-2_5);
    box-shadow: var(--shadow-lg);
    min-width: 300px; text-align: center;
    animation: ai-card-in 0.18s ease-out;
  }
  @keyframes ai-card-in {
    from { opacity: 0; transform: translateY(4px); }
    to   { opacity: 1; transform: translateY(0); }
  }
  .ai-status-icon {
    width: 48px; height: 48px; border-radius: 50%;
    background: var(--accent-soft);
    border: 1px solid var(--accent-edge);
    display: flex; align-items: center; justify-content: center;
    margin-bottom: var(--sp-1);
  }
  .ai-status-icon i { font-size: 24px; color: var(--accent); }
  .ai-status-context {
    font-size: var(--text-xs); font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase;
    color: var(--accent); padding: 3px var(--sp-2_5); border-radius: 999px;
    background: var(--accent-soft); border: 1px solid var(--accent-edge);
    margin-bottom: var(--sp-1);
  }
  .ai-status-title { font-size: var(--text-lg); font-weight: 700; color: var(--text-primary); letter-spacing: -0.01em; }
  .ai-status-sub   { font-size: var(--text-sm); color: var(--text-muted); line-height: 1.5; }
  .ai-status-steps {
    display: flex; flex-direction: column; gap: 5px; width: 100%;
    margin-top: var(--sp-1_5); padding-top: var(--sp-3); border-top: 1px solid var(--border);
  }
  @keyframes stepIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: none; } }
  .ai-step {
    display: flex; align-items: center; gap: var(--sp-2);
    font-size: var(--text-xs); color: var(--text-muted); padding: 3px 0;
    animation: stepIn 0.2s ease backwards;
  }
  .ai-step:nth-child(1) { animation-delay: 0.04s; }
  .ai-step:nth-child(2) { animation-delay: 0.10s; }
  .ai-step:nth-child(3) { animation-delay: 0.16s; }
  .ai-step:nth-child(4) { animation-delay: 0.22s; }
  .ai-step:nth-child(5) { animation-delay: 0.28s; }
  .ai-step:nth-child(6) { animation-delay: 0.34s; }
  .ai-step:nth-child(7) { animation-delay: 0.40s; }
  .ai-step i { font-size: var(--text-base); width: 14px; flex-shrink: 0; }
  .ai-step.done    { color: #22c55e; }
  .ai-step.active  { color: var(--text-primary); font-weight: 500; }
  .ai-step.pending { color: var(--text-muted); opacity: 0.5; }
  .ai-status-progress {
    display: flex; align-items: center;
    width: 100%; margin-top: var(--sp-2);
  }
  .ai-status-bar-track {
    flex: 1; height: 3px; border-radius: 999px;
    background: var(--border); overflow: hidden;
  }
  /* Honest indeterminate bar — Gemini calls have no streaming progress, so a
     slice slides across rather than implying a known percentage. */
  .ai-status-bar-track.is-indeterminate .ai-status-bar-fill {
    width: 35%; border-radius: 999px; height: 100%;
    background: var(--accent);
    animation: ai-bar-slide 1.1s ease-in-out infinite;
  }
  @keyframes ai-bar-slide {
    0%   { transform: translateX(-120%); }
    100% { transform: translateX(385%); }
  }

  /* Upload loading state */
  .upload-loading { display: none; flex-direction: column; align-items: center; gap: var(--sp-3_5); padding: 52px 72px; background: #fff; border-radius: var(--radius-xl); box-shadow: var(--shadow-md); border: 1px solid var(--border); }
  .upload-loading-icon i { font-size: 36px; color: var(--accent); }
  .upload-loading-title { font-size: var(--text-lg); font-weight: 600; color: var(--text-primary); }
  .upload-loading-track { width: 240px; height: 6px; background: var(--border); border-radius: 3px; overflow: hidden; }
  .upload-loading-fill { height: 100%; width: 0%; background: var(--accent); border-radius: 3px; transition: width 0.12s ease; }
  .upload-loading-pct { font-size: var(--text-sm); color: var(--text-muted); font-weight: 500; }
  #uploadOverlay.loading .upload-choice-row,
  #uploadOverlay.loading .upload-box,
  #uploadOverlay.loading .upload-alt,
  #uploadOverlay.loading .btn-demo { display: none; }
  #uploadOverlay.loading .upload-loading { display: flex; }
  .btn-demo { display: inline-flex; align-items: center; gap: var(--sp-1_5); padding: 9px 18px; font-size: var(--text-base); font-weight: 500; background: #fff; color: #475569; border: 1px solid rgba(100,116,139,0.2); border-radius: var(--radius-md); cursor: pointer; transition: all 0.2s; box-shadow: var(--shadow-sm); }
  .btn-demo:hover { background: #f8fafc; border-color: var(--accent); color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }

  /* ── Status bar ── */
  .status-bar { display: flex; align-items: center; height: 28px; padding: 0 var(--sp-4); background: var(--bg-sidebar); border-top: 1px solid var(--border); flex-shrink: 0; }
  .status-item { display: flex; align-items: center; gap: 5px; font-size: var(--text-xs); color: var(--text-muted); padding: 0 var(--sp-3); border-right: 1px solid var(--border); }
  .status-item:first-child { padding-left: 0; }
  .status-item i { font-size: var(--text-sm); }
  .status-value { color: var(--text-secondary); font-weight: 500; }
  .status-spacer { flex: 1; }
  .status-right { display: flex; gap: 0; }
  .status-zoom-group { gap: 3px; padding: 0 var(--sp-2); }
  .status-zoom-label { min-width: 34px; text-align: center; font-weight: 500; color: var(--text-secondary); font-size: var(--text-xs); }
  .status-zoom-btn {
    background: none; border: none; padding: 0;
    width: 18px; height: 18px; display: flex; align-items: center; justify-content: center;
    cursor: pointer; border-radius: 3px; color: var(--text-muted); font-size: var(--text-xs);
    transition: color var(--transition), background var(--transition);
  }
  .status-zoom-btn:hover { color: var(--text-primary); background: rgba(255,255,255,0.07); }

  /* ── Modals ── */
  .modal-bg { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.6); backdrop-filter: blur(4px); z-index: 100; align-items: center; justify-content: center; }
  .modal-bg.open { display: flex; }
  .modal { background: var(--bg-modal); border-radius: var(--radius-xl); border: 1px solid var(--border); padding: var(--sp-7); max-width: 520px; width: 90%; max-height: 82vh; overflow-y: auto; box-shadow: var(--shadow-lg); }
  .modal::-webkit-scrollbar { width: 4px; }
  .modal::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 2px; }
  .modal-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--sp-5); }
  .modal-title { display: flex; align-items: center; gap: var(--sp-2_5); font-size: 17px; font-weight: 600; color: var(--text-primary); }
  .modal-title-icon { width: 34px; height: 34px; border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; font-size: var(--text-2xl); }
  .modal-title-icon.yellow { background: rgba(251,191,36,0.12); border: 1px solid rgba(251,191,36,0.2); color: #fbbf24; }
  .modal-title-icon.purple { background: rgba(139,92,246,0.12); border: 1px solid rgba(139,92,246,0.2); color: #a78bfa; }
  .modal-title-icon.blue { background: rgba(59,130,246,0.12); border: 1px solid rgba(59,130,246,0.2); color: #60a5fa; }
  .modal-desc { font-size: var(--text-base); color: var(--text-secondary); margin-bottom: var(--sp-4); line-height: 1.6; }
  .reco-item { padding: var(--sp-3) var(--sp-3_5); border: 1px solid var(--border); border-radius: var(--radius-md); margin-bottom: var(--sp-2); background: var(--bg-card); transition: all var(--transition); }
  .reco-item:hover { border-color: rgba(255,255,255,0.12); }
  .reco-item h4 { font-size: var(--text-sm); font-weight: 600; color: var(--text-primary); margin-bottom: var(--sp-1); }
  .reco-item p { font-size: var(--text-xs); color: var(--text-secondary); line-height: 1.5; }
  .reco-footer { margin-top: var(--sp-3_5); padding: var(--sp-3) var(--sp-3_5); background: rgba(59,130,246,0.06); border: 1px solid rgba(59,130,246,0.15); border-radius: var(--radius-md); }
  .reco-footer p { font-size: var(--text-xs); color: var(--text-secondary); line-height: 1.5; }

  /* ── API Key input ── */
  .api-key-input-wrap { position: relative; margin-bottom: var(--sp-3); }
  .api-key-input { width: 100%; padding: 9px 38px 9px var(--sp-2_5); font-size: var(--text-sm); background: var(--bg-input); color: var(--text-primary); border: 1px solid var(--border-input); border-radius: var(--radius-md); letter-spacing: 0.04em; }
  .api-key-input:focus { outline: none; border-color: var(--border-focus); }
  .api-key-toggle { position: absolute; right: 8px; top: 50%; transform: translateY(-50%); background: none; border: none; color: var(--text-muted); cursor: pointer; font-size: var(--text-lg); padding: var(--sp-0_5); }
  .api-key-hint { font-size: var(--text-2xs); color: var(--text-muted); margin-top: var(--sp-1_5); }

  /* ── Toasts ── */
  .toast-container { position: fixed; bottom: 40px; right: 20px; z-index: 4000; display: flex; flex-direction: column; gap: var(--sp-2); pointer-events: none; transition: right 0.22s ease; }
  /* While the 320px chat panel is open (desktop only), slide toasts left of it
     so they don't overlay the chat. Mobile panel is full-width — left as-is. */
  @media (min-width: 769px) {
    body:has(.chat-panel.open) .toast-container { right: 340px; }
  }
  .toast {
    display: flex; align-items: center; gap: 9px;
    padding: var(--sp-2_5) var(--sp-3_5); border-radius: var(--radius-md);
    background: var(--bg-modal); border: 1px solid var(--border);
    box-shadow: var(--shadow-lg); font-size: var(--text-sm); color: var(--text-primary);
    opacity: 0; transform: translateY(8px) scale(0.97);
    transition: all 0.22s ease; pointer-events: auto; max-width: 320px;
  }
  .toast.visible { opacity: 1; transform: none; }
  .toast.exiting { opacity: 0; transform: translateX(24px) scale(0.96); }
  .toast i { font-size: var(--text-lg); flex-shrink: 0; }
  .toast-success { border-color: rgba(34,197,94,0.3); }
  .toast-success i { color: #22c55e; }
  .toast-error { border-color: rgba(239,68,68,0.3); }
  .toast-error i { color: #f87171; }
  .toast-info i { color: #60a5fa; }
  .toast-warning i { color: #fbbf24; }
  .toast { pointer-events: auto; cursor: pointer; }
  .toast:hover { border-color: rgba(255,255,255,0.14); }
  .toast-msg { flex: 1; }
  .toast-actions { display: flex; gap: var(--sp-1); margin-left: var(--sp-1); }
  .toast-action { padding: 3px 9px; font-size: var(--text-xs); font-weight: 600; border-radius: var(--radius-sm); border: 1px solid rgba(255,255,255,0.18); background: rgba(255,255,255,0.08); color: var(--text-primary); cursor: pointer; white-space: nowrap; }
  .toast-action:hover { background: rgba(255,255,255,0.16); }

  /* ── Current tool pill ── */
  .canvas-tool-pill {
    position: absolute; top: 14px; left: 50%; transform: translateX(-50%); z-index: 100;
    display: flex; align-items: center; gap: 7px;
    padding: var(--sp-1_5) var(--sp-3); border-radius: 999px;
    background: var(--bg-modal); border: 1px solid var(--border);
    box-shadow: var(--shadow-lg); font-size: var(--text-sm); font-weight: 600;
    color: var(--text-primary); pointer-events: none; white-space: nowrap;
  }
  .canvas-tool-pill i { font-size: var(--text-lg); flex-shrink: 0; }

  /* ── "Did you know" canvas hint pill ── */
  .canvas-hint {
    position: absolute; top: 14px; left: 14px; transform: translateY(-6px);
    z-index: 100; display: flex; align-items: center; gap: 9px;
    max-width: min(420px, calc(50% - 120px));
    padding: var(--sp-2) var(--sp-2_5) var(--sp-2) 13px; border-radius: 999px;
    background: var(--bg-modal); border: 1px solid var(--border);
    box-shadow: var(--shadow-lg); font-size: var(--text-sm); color: var(--text-secondary);
    opacity: 0; transition: opacity 0.25s ease, transform 0.25s ease; pointer-events: auto;
  }
  .canvas-hint[hidden] { display: none; }
  .canvas-hint.visible { opacity: 1; transform: translateY(0); }
  .canvas-hint-icon { font-size: var(--text-lg); flex-shrink: 0; color: #fbbf24; }
  .canvas-hint-text { flex: 1; min-width: 0; line-height: 1.45; }
  .canvas-hint-text b { color: var(--text-primary); font-weight: 600; }
  .canvas-hint-close {
    flex-shrink: 0; width: 22px; height: 22px; padding: 0; display: inline-flex;
    align-items: center; justify-content: center; border-radius: 50%;
    background: transparent; border: none; color: var(--text-muted); cursor: pointer;
    font-size: var(--text-base); transition: background 0.15s, color 0.15s;
  }
  .canvas-hint-close:hover { background: rgba(255,255,255,0.08); color: var(--text-primary); }
  /* Unsaved design indicator dot on Versions button */
  #btnVersions.has-unsaved::after { content: ''; display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); margin-left: var(--sp-1); vertical-align: middle; }

  /* ── Shortcut hint tooltip ── */
  .shortcut-hint { font-size: 9px; color: var(--text-muted); background: rgba(255,255,255,0.05); padding: var(--sp-px) 5px; border-radius: 3px; border: 1px solid var(--border); font-family: monospace; }

  /* ── Keyboard Shortcut Modal ── */
  .shortcut-list { display: flex; flex-direction: column; gap: var(--sp-1); }
  .shortcut-row { display: flex; align-items: center; gap: 5px; font-size: var(--text-sm); color: var(--text-secondary); padding: 3px 0; }
  .shortcut-row span { margin-left: var(--sp-1); }
  kbd { display: inline-flex; align-items: center; justify-content: center; min-width: 22px; padding: var(--sp-px) 5px; font-size: var(--text-2xs); font-family: monospace; font-weight: 600; color: var(--text-primary); background: rgba(255,255,255,0.06); border: 1px solid var(--border); border-bottom-width: 2px; border-radius: 4px; white-space: nowrap; }
  .btn kbd { font-size: 9px; min-width: 14px; padding: 0 3px; opacity: 0.55; margin-left: var(--sp-px); border-bottom-width: 1px; }
  body.hide-kbd kbd { display: none; }
  .modal-title-icon { background: rgba(59,130,246,0.1); border: 1px solid rgba(59,130,246,0.2); color: #60a5fa; }

  /* ── Unit Picker ── */
  .unit-category-label { font-size: 9px; font-weight: 700; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.08em; margin: var(--sp-2) 0 var(--sp-1); }
  .unit-category-label:first-child { margin-top: 0; }
  .unit-card {
    display: flex; align-items: center; gap: var(--sp-2);
    padding: 7px 9px; border-radius: var(--radius-md);
    border: 1px solid var(--border); cursor: pointer;
    background: transparent; margin-bottom: 3px;
    transition: all var(--transition);
  }
  .unit-card:hover { background: rgba(255,255,255,0.04); border-color: rgba(255,255,255,0.12); }
  .unit-card.active { background: var(--accent-light); border-color: var(--border-focus); }
  .unit-card-icon {
    width: 30px; height: 30px; border-radius: var(--radius-sm); flex-shrink: 0;
    background: rgba(255,255,255,0.05); border: 1px solid var(--border);
    display: flex; align-items: center; justify-content: center; font-size: var(--text-md);
  }
  .unit-card.active .unit-card-icon { background: var(--accent-light); border-color: rgba(59,130,246,0.4); }
  .unit-card-body { flex: 1; min-width: 0; }
  .unit-card-name { font-size: var(--text-xs); font-weight: 600; color: var(--text-primary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .unit-card-meta { font-size: var(--text-2xs); color: var(--text-muted); margin-top: var(--sp-px); }
  .unit-card-kw { font-size: var(--text-2xs); font-weight: 600; color: var(--accent); flex-shrink: 0; }
  .unit-search {
    width: 100%; padding: 5px var(--sp-2); margin-bottom: var(--sp-1_5); box-sizing: border-box;
    background: var(--bg-input); color: var(--text-primary);
    border: 1px solid var(--border-input); border-radius: var(--radius-sm);
    font-size: var(--text-xs); font-family: var(--font); outline: none;
  }
  .unit-search:focus { border-color: var(--border-focus); }
  .unit-search::placeholder { color: var(--text-muted); }
  .unit-no-match { font-size: var(--text-xs); color: var(--text-muted); padding: var(--sp-2) 0; }
  .unit-specs-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-1); margin-top: var(--sp-2); }
  .unit-spec-box { background: rgba(255,255,255,0.03); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 5px 7px; }
  .unit-spec-label { font-size: 9px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; }
  .unit-spec-val { font-size: var(--text-sm); font-weight: 600; color: var(--text-primary); margin-top: var(--sp-px); }

  /* ── Scrollbar ── */
  ::-webkit-scrollbar { width: 6px; height: 6px; }
  ::-webkit-scrollbar-track { background: transparent; }
  ::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.08); border-radius: 3px; }

  /* ── Animations ── */
  @keyframes fadeIn { from { opacity: 0; transform: scale(0.96); } to { opacity: 1; transform: scale(1); } }
  .modal-bg.open .modal { animation: fadeIn 0.18s ease; }
  @keyframes spin { to { transform: rotate(360deg); } }
  .spin { animation: spin 0.8s linear infinite; }

  /* ── Settings Modal ── */
  .settings-modal { max-width: 600px; padding-bottom: var(--sp-5); }
  .settings-tab-bar { display: flex; border-bottom: 1px solid var(--border); margin: 0 -28px var(--sp-5); padding: 0 var(--sp-5); gap: var(--sp-0_5); overflow-x: auto; scrollbar-width: none; }
  .settings-tab-bar::-webkit-scrollbar { display: none; }
  .settings-tab { flex: none; display: flex; align-items: center; gap: var(--sp-1_5); padding: var(--sp-2) var(--sp-3_5) 7px; background: none; border: none; border-bottom: 2px solid transparent; margin-bottom: -1px; cursor: pointer; font-size: var(--text-sm); font-weight: 600; color: var(--text-muted); transition: color var(--transition); white-space: nowrap; }
  .settings-tab i { font-size: var(--text-md); }
  .settings-tab:hover { color: var(--text-secondary); }
  .settings-tab.active { color: var(--accent); border-bottom-color: var(--accent); }
  .settings-pane { display: none; }
  .settings-pane.active { display: block; }
  .settings-section { margin-bottom: 22px; }
  .settings-section:last-child { margin-bottom: 0; }
  .settings-section-title { font-size: var(--text-2xs); font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: var(--sp-2_5); }
  .settings-row { display: flex; align-items: center; justify-content: space-between; padding: 7px 0; border-bottom: 1px solid var(--border); gap: var(--sp-3); }
  .settings-row:last-child { border-bottom: none; }
  .settings-row-wrap { flex-direction: column; align-items: stretch; gap: 0; }
  .settings-row-wrap:last-child { border-bottom: none; }
  .settings-row-label { font-size: var(--text-sm); color: var(--text-secondary); }
  .settings-row-desc { font-size: var(--text-2xs); color: var(--text-muted); padding: 3px 0 5px; }
  .btn-link { background: none; border: none; color: var(--text-muted); font-size: var(--text-xs); cursor: pointer; padding: 0; text-decoration: underline; }
  .btn-link:hover { color: var(--text-secondary); }
  .no-grid { background-image: none !important; }

  .theme-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--sp-2); }
  .theme-card { border: 2px solid var(--border); border-radius: var(--radius-md); cursor: pointer; overflow: hidden; transition: all var(--transition); }
  .theme-card:hover { border-color: rgba(255,255,255,0.2); transform: translateY(-1px); }
  .theme-card.active { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
  .theme-preview { height: 52px; display: flex; gap: 3px; padding: 5px; }
  .theme-preview-sidebar { width: 30%; border-radius: 3px 0 0 3px; }
  .theme-preview-canvas { flex: 1; border-radius: 0 3px 3px 0; position: relative; }
  .theme-preview-dot { width: 8px; height: 8px; border-radius: 50%; position: absolute; bottom: 5px; right: 5px; }
  .theme-name { font-size: var(--text-2xs); font-weight: 500; text-align: center; padding: 5px var(--sp-0_5); color: var(--text-secondary); }
  .theme-card.active .theme-name { color: var(--accent); font-weight: 600; }

  .accent-swatch-row { display: flex; gap: var(--sp-2); flex-wrap: wrap; }
  .accent-dot { width: 28px; height: 28px; border-radius: 50%; border: 3px solid transparent; cursor: pointer; transition: all var(--transition); }
  .accent-dot:hover { transform: scale(1.18); }
  .accent-dot.active { border-color: rgba(255,255,255,0.85); box-shadow: 0 0 0 2px currentColor; }

  .icon-grid { display: grid; grid-template-columns: repeat(8, 1fr); gap: var(--sp-1_5); }
  .icon-option {
    aspect-ratio: 1; display: flex; align-items: center; justify-content: center;
    border: 1px solid var(--border); border-radius: var(--radius-md);
    background: transparent; color: var(--text-secondary); font-size: var(--text-2xl);
    cursor: pointer; transition: all var(--transition);
  }
  .icon-option:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); border-color: rgba(255,255,255,0.14); }
  .icon-option.active { background: var(--accent-light); color: var(--accent); border-color: var(--border-focus); }

  .settings-name-preview {
    display: flex; align-items: center; gap: var(--sp-2);
    padding: 9px var(--sp-3); background: var(--bg-card); border-radius: var(--radius-md);
    border: 1px solid var(--border); margin-top: var(--sp-2);
  }
  .logo-icon-preview {
    width: 24px; height: 24px; border-radius: 6px;
    display: flex; align-items: center; justify-content: center;
    font-size: var(--text-base); color: #fff;
  }
  .logo-name { font-size: var(--text-base); font-weight: 600; color: var(--text-primary); }

  /* ── Duct colour swatches ── */
  .duct-colour-row { display: flex; gap: 18px; margin-top: var(--sp-1); flex-wrap: wrap; }
  .duct-swatch-item { display: flex; flex-direction: column; align-items: center; gap: 5px; }
  .duct-swatch {
    width: 34px; height: 34px; border-radius: var(--radius-md); position: relative;
    border: 2px solid rgba(255,255,255,0.15); cursor: pointer;
    transition: transform var(--transition), border-color var(--transition);
    display: flex; align-items: center; justify-content: center;
  }
  .duct-swatch:hover { transform: scale(1.1); border-color: rgba(255,255,255,0.35); }
  .duct-swatch input[type="color"] { opacity: 0; position: absolute; inset: 0; width: 100%; height: 100%; cursor: pointer; border: none; padding: 0; }
  .duct-swatch-label { font-size: var(--text-2xs); color: var(--text-muted); font-weight: 500; }
  .duct-colour-presets { display: flex; gap: var(--sp-1_5); margin-top: var(--sp-2_5); }
  .duct-preset-btn {
    flex: 1; padding: 5px var(--sp-2); font-size: var(--text-xs); font-weight: 500;
    background: var(--bg-card); color: var(--text-secondary);
    border: 1px solid var(--border); border-radius: var(--radius-md);
    cursor: pointer; transition: all var(--transition);
  }
  .duct-preset-btn:hover { background: var(--bg-card-hover); color: var(--text-primary); }
  .duct-preset-btn.active { background: var(--accent-light); color: var(--accent); border-color: var(--border-focus); }

  /* ── UI Density toggle ── */
  .density-toggle { display: flex; border: 1px solid var(--border); border-radius: var(--radius-md); overflow: hidden; }
  .density-btn {
    flex: 1; padding: var(--sp-1_5) var(--sp-1); font-size: var(--text-xs); font-weight: 500;
    background: none; border: none; border-right: 1px solid var(--border);
    color: var(--text-muted); cursor: pointer; transition: all var(--transition);
  }
  .density-btn:last-child { border-right: none; }
  .density-btn:hover { background: rgba(255,255,255,0.05); color: var(--text-secondary); }
  .density-btn.active { background: var(--accent-light); color: var(--accent); }

  /* ── Density body classes ── */
  body.density-compact .sidebar-section { padding: 5px var(--sp-2_5); }
  body.density-compact .section-header { margin-bottom: var(--sp-1); }
  body.density-compact .settings-row { padding: var(--sp-1) 0; }
  body.density-comfortable .sidebar-section { padding: var(--sp-3) var(--sp-2_5); }
  body.density-comfortable .section-header { margin-bottom: var(--sp-2_5); }
  body.density-comfortable .settings-row { padding: var(--sp-2_5) 0; }

/* ── Library Modal ─────────────────────────────────────────── */
.library-modal { max-width: 560px; }
.library-tabs {
  display: flex; gap: var(--sp-1); margin-bottom: 18px;
  border-bottom: 1px solid var(--border); padding-bottom: var(--sp-1);
}
.lib-tab {
  display: flex; align-items: center; gap: var(--sp-1_5);
  padding: var(--sp-1_5) var(--sp-3_5); border-radius: var(--radius-md) var(--radius-md) 0 0;
  border: 1px solid transparent; border-bottom: none;
  font-size: var(--text-sm); font-weight: 500; cursor: pointer;
  color: var(--text-secondary); background: transparent;
  transition: all var(--transition);
}
.lib-tab:hover { color: var(--text-primary); background: var(--bg-card); }
.lib-tab.active { color: var(--accent); background: var(--bg-card); border-color: var(--border); }
.lib-section-title {
  font-size: var(--text-2xs); font-weight: 600; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: var(--sp-2_5);
}
.lib-form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-2); }
.lib-form-row { display: flex; flex-direction: column; gap: var(--sp-1); min-width: 0; }
.lib-form-row .prop-input { width: 100%; box-sizing: border-box; }
.lib-form-label { font-size: var(--text-2xs); color: var(--text-muted); font-weight: 500; }
.lib-item {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-2_5); background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius-md);
  margin-bottom: var(--sp-1);
}
.lib-item-body { flex: 1; min-width: 0; }
.lib-item-name { font-size: var(--text-sm); font-weight: 600; color: var(--text-primary); }
.lib-item-meta { font-size: var(--text-2xs); color: var(--text-muted); margin-top: var(--sp-px); }
.lib-item-badge {
  font-size: 9px; font-weight: 600; letter-spacing: 0.06em;
  padding: var(--sp-0_5) var(--sp-1_5); border-radius: 10px; white-space: nowrap;
  background: var(--accent-light); color: var(--accent);
  border: 1px solid rgba(var(--accent-rgb,59,130,246),0.2);
}

/* ── Generate Layout topbar button ── */
.btn-gen {
  background: linear-gradient(135deg, rgba(34,197,94,0.12), rgba(16,185,129,0.12));
  border-color: rgba(34,197,94,0.3); color: #4ade80;
}
.btn-gen:hover { background: linear-gradient(135deg, rgba(34,197,94,0.22), rgba(16,185,129,0.22)); border-color: rgba(34,197,94,0.5); color: #86efac; }

/* ── Topbar separator ── */
.topbar-sep { width: 1px; height: 20px; background: var(--border); margin: 0 var(--sp-1_5); flex-shrink: 0; }

/* Text labels for the icon-only topbar actions (Messages, Account). Hidden by
   default so those buttons stay icon-only on desktop; the mobile kebab menu
   (where actions become full-width rows) reveals them so they don't read as
   blank rows. See the ≤768px .topbar-actions block. */
.topbar-action-label { display: none; }

/* ── Toolbar spacer & tool group ── */
.toolbar-spacer { flex: 1; }
.tool-group { display: flex; align-items: center; gap: var(--sp-0_5); }

/* ── Sidebar mobile drawer header (hidden on desktop) ── */
.sidebar-mobile-header { display: none; }

/* ── Sidebar tab nav ── */
.sidebar-tabs {
  display: flex; flex-shrink: 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-sidebar);
}
.sidebar-tab {
  flex: 1; display: flex; flex-direction: row; align-items: center; justify-content: center;
  gap: var(--sp-1_5); padding: 11px var(--sp-1);
  background: none; border: none; cursor: pointer;
  color: var(--text-muted); font-size: var(--text-sm); font-weight: 600;
  letter-spacing: 0.01em; position: relative;
  transition: color var(--transition), background var(--transition);
  border-bottom: 2px solid transparent; margin-bottom: -1px;
}
.sidebar-tab i { font-size: var(--text-xl); }
.sidebar-tab:hover { color: var(--text-secondary); background: rgba(255,255,255,0.04); }
.sidebar-tab.active { color: var(--accent); border-bottom-color: var(--accent); background: var(--accent-light); }

/* ── Active-tab hint row ── */
.sidebar-hint {
  flex-shrink: 0; display: flex; align-items: center; gap: var(--sp-1_5);
  padding: 7px var(--sp-3); font-size: var(--text-xs); line-height: 1.3;
  color: var(--text-muted); background: var(--bg-sidebar);
  border-bottom: 1px solid var(--border);
}
.sidebar-hint i { font-size: var(--text-base); flex-shrink: 0; opacity: 0.8; }

.sidebar-collapse-btn {
  flex-shrink: 0; width: 30px;
  display: flex; align-items: center; justify-content: center;
  background: none; border: none; cursor: pointer;
  color: var(--text-muted); font-size: var(--text-lg);
  border-left: 1px solid var(--border);
  transition: color var(--transition), background var(--transition);
}
.sidebar-collapse-btn:hover { color: var(--text-secondary); background: rgba(255,255,255,0.04); }

.s-tab-badge {
  flex-shrink: 0;
  min-width: 16px; height: 16px; padding: 0 var(--sp-1);
  background: var(--accent); color: #fff;
  font-size: 9px; font-weight: 700; border-radius: 8px;
  display: none; align-items: center; justify-content: center;
}
.s-tab-badge.visible { display: inline-flex; }
.s-tab-badge-warn { background: #ef4444; color: #fff; }
/* In the collapsed rail there's no label, so float the single badge onto the icon. */
.sidebar.collapsed .s-tab-badge { position: absolute; top: 3px; right: 5px; }

/* ── Sidebar panes ── */
.sidebar-pane {
  display: none; flex: 1; overflow-y: auto; overflow-x: hidden; flex-direction: column;
}
.sidebar-pane.active { display: flex; }
.sidebar-pane::-webkit-scrollbar { width: 4px; }
.sidebar-pane::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 2px; }

/* ── Properties no-selection hint ── */
.props-no-sel {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: var(--sp-2_5); padding: var(--sp-10) var(--sp-5); text-align: center;
  color: var(--text-muted); font-size: var(--text-xs); line-height: 1.5;
}
.props-no-sel i { font-size: 28px; opacity: 0.4; }

/* ── Accordion sidebar sections ── */
.acc-section { padding: 0; }
.acc-section:first-child .acc-header { border-top: none; }

.acc-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--sp-2_5) var(--sp-3); cursor: pointer; user-select: none;
  background: rgba(255,255,255,0.018);
  transition: background var(--transition);
}
.acc-header:hover { background: rgba(255,255,255,0.06); }
.acc-section:not(.collapsed) > .acc-header { background: rgba(255,255,255,0.035); }

.acc-title-wrap {
  display: flex; align-items: center; gap: 7px; flex: 1; min-width: 0;
}
.acc-icon { font-size: var(--text-md); color: var(--accent); flex-shrink: 0; opacity: 0.85; }
.acc-chevron {
  font-size: var(--text-md); color: var(--text-secondary); flex-shrink: 0;
  transition: transform 0.22s ease;
}
.acc-section.collapsed .acc-chevron { transform: rotate(-90deg); }
.acc-header:hover .acc-chevron { color: var(--text-primary); }

.acc-body-grid {
  display: grid; grid-template-rows: 1fr;
  transition: grid-template-rows 0.22s ease;
}
.acc-section.collapsed .acc-body-grid { grid-template-rows: 0fr; }

.acc-body-inner {
  overflow: hidden; min-height: 0;
  padding: var(--sp-2) var(--sp-2_5) var(--sp-3);
}

/* ── Section header improvements ── */
.section-header {
  display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--sp-2_5);
}
.section-header-left { display: flex; align-items: center; gap: 7px; flex: 1; min-width: 0; }

/* ── Section badge (element count etc.) ── */
.section-badge {
  font-size: var(--text-xs); font-weight: 600;
  background: rgba(255,255,255,0.08); color: var(--text-secondary);
  padding: var(--sp-px) 7px; border-radius: 10px; min-width: 20px; text-align: center;
  flex-shrink: 0;
}

/* ── Properties hint ── */
.props-hint { font-size: var(--text-2xs); color: var(--text-muted); margin-top: var(--sp-2); line-height: 1.5; }

/* ── Auth gate ── */
.auth-gate {
  position: fixed; inset: 0; background: rgba(0,0,0,0.7); backdrop-filter: blur(8px);
  z-index: 500; display: flex; align-items: center; justify-content: center;
}
.auth-gate-card {
  background: var(--bg-modal); border: 1px solid var(--border); border-radius: var(--radius-xl);
  padding: var(--sp-10) 36px; max-width: 380px; width: 90%; text-align: center;
  box-shadow: var(--shadow-lg);
}
.auth-gate-logo { margin-bottom: var(--sp-7); }
.auth-gate-icon {
  width: 56px; height: 56px; border-radius: 14px; margin: 0 auto var(--sp-3);
  background: linear-gradient(135deg, var(--accent), var(--brand-secondary));
  display: flex; align-items: center; justify-content: center;
  font-size: 28px; color: #fff; box-shadow: 0 4px 20px var(--accent-glow);
}
.auth-gate-name { font-size: 20px; font-weight: 700; }
.auth-gate-btn {
  display: flex; align-items: center; justify-content: center; gap: var(--sp-2);
  width: 100%; padding: var(--sp-3); font-size: var(--text-md); font-weight: 600;
  background: var(--accent); color: #fff; border: none; border-radius: var(--radius-md);
  cursor: pointer; text-decoration: none; margin-bottom: var(--sp-2_5);
  transition: background var(--transition);
}
.auth-gate-btn:hover { background: var(--accent-hover); }
.auth-gate-guest-btn {
  width: 100%; padding: var(--sp-2_5); font-size: var(--text-base); color: var(--text-muted);
  background: transparent; border: 1px solid var(--border); border-radius: var(--radius-md);
  cursor: pointer; font-family: var(--font); transition: all var(--transition);
  display: flex; align-items: center; justify-content: center; gap: var(--sp-2);
}
.auth-gate-guest-btn:hover { border-color: rgba(255,255,255,0.18); color: var(--text-primary); }
.auth-gate-home-link {
  display: flex; align-items: center; justify-content: center; gap: var(--sp-1);
  margin-top: var(--sp-3); font-size: var(--text-base); color: var(--text-muted);
  text-decoration: none; transition: color var(--transition);
}
.auth-gate-home-link:hover { color: var(--text-primary); }

/* ── User avatar + dropdown ── */
.user-menu-wrap { position: relative; }
.user-avatar-btn {
  display: flex; align-items: center; gap: var(--sp-1); padding: var(--sp-1) var(--sp-2) var(--sp-1) var(--sp-1);
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 99px;
  cursor: pointer; transition: all var(--transition);
}
.user-avatar-btn:hover { border-color: rgba(255,255,255,0.18); background: var(--bg-card-hover); }
.user-avatar-initials {
  width: 26px; height: 26px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--brand-secondary));
  color: #fff; font-size: var(--text-sm); font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.user-dropdown {
  display: none; position: absolute; top: calc(100% + 6px); right: 0;
  background: var(--bg-modal); border: 1px solid var(--border);
  border-radius: var(--radius-md); box-shadow: var(--shadow-md);
  min-width: 200px; z-index: 50; overflow: hidden;
  animation: fadeIn 0.12s ease;
}
.user-dropdown.open { display: block; }
.user-dropdown-header { padding: var(--sp-3) var(--sp-3_5); border-bottom: 1px solid var(--border); }
.user-dropdown-name { font-size: var(--text-base); font-weight: 600; color: var(--text-primary); }
.user-dropdown-email { font-size: var(--text-xs); color: var(--text-muted); margin-top: var(--sp-0_5); }
.user-dropdown-item {
  display: flex; align-items: center; gap: 9px; width: 100%;
  padding: var(--sp-2_5) var(--sp-3_5); background: none; border: none;
  color: var(--text-secondary); font-size: var(--text-base); font-family: var(--font);
  cursor: pointer; text-align: left; transition: background var(--transition);
}
.user-dropdown-item i { font-size: var(--text-lg); color: var(--text-muted); }
.user-dropdown-item:hover { background: var(--bg-card-hover); color: var(--text-primary); }
.user-dropdown-divider { height: 1px; background: var(--border); margin: var(--sp-1) 0; }
.user-dropdown-signout { color: #f87171; }
.user-dropdown-signout i { color: #f87171; }
.user-dropdown-signout:hover { background: rgba(239,68,68,0.08); }

/* ── Cloud project list (in Projects modal) ── */
.cloud-project-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--sp-2_5) var(--sp-3); border: 1px solid var(--border); border-radius: var(--radius-md);
  margin-bottom: var(--sp-2); background: var(--bg-card); gap: var(--sp-3);
  transition: border-color var(--transition);
}
.cloud-project-row:hover { border-color: rgba(255,255,255,0.14); }
.cloud-project-name { font-size: var(--text-base); font-weight: 600; color: var(--text-primary); }
.cloud-project-meta { font-size: var(--text-xs); color: var(--text-muted); margin-top: var(--sp-0_5); }

/* ── Export dropdown ── */
.export-dropdown-wrap { position: relative; }
.export-dropdown {
  display: none; position: absolute; top: calc(100% + 6px); right: 0;
  background: var(--bg-modal); border: 1px solid var(--border);
  border-radius: var(--radius-md); box-shadow: var(--shadow-md);
  min-width: 210px; z-index: 50; overflow: hidden;
}
.export-dropdown.open { display: block; animation: fadeIn 0.12s ease; }
.export-dropdown-item {
  display: flex; align-items: center; gap: 9px;
  width: 100%; padding: 9px var(--sp-3_5); background: none; border: none;
  color: var(--text-secondary); font-size: var(--text-sm); font-family: var(--font);
  cursor: pointer; text-align: left; transition: background var(--transition);
}
.export-dropdown-item i { font-size: var(--text-lg); color: var(--text-muted); }
.export-dropdown-item:hover { background: var(--bg-card-hover); color: var(--text-primary); }
.export-dropdown-item:hover i { color: var(--accent); }
.export-dropdown-item + .export-dropdown-item { border-top: 1px solid var(--border); }

/* Grouped AI menu: section captions + prerequisite-gated (disabled) items */
.dropdown-section-label {
  padding: 7px var(--sp-3_5) 3px;
  font-size: 9px; font-weight: 700; letter-spacing: .07em; text-transform: uppercase;
  color: var(--text-muted); opacity: .7; user-select: none;
}
.dropdown-section-label + .export-dropdown-item { border-top: none; }
.dropdown-section-label.done { color: var(--success, #22c55e); opacity: .85; }
.dropdown-section-label .ti-circle-check { color: var(--success, #22c55e); font-size: var(--text-sm); }
.export-dropdown-item:disabled { opacity: .4; cursor: not-allowed; }
.export-dropdown-item:disabled:hover { background: none; color: var(--text-secondary); }
.export-dropdown-item:disabled:hover i { color: var(--text-muted); }

/* Step-of-4 progress header at the top of the AI menu */
.ai-progress-header {
  position: relative;
  padding: 8px var(--sp-3_5) 9px;
  font-size: 10.5px; font-weight: 600; color: var(--text-secondary);
  background: var(--bg-card-hover);
  border-bottom: 1px solid var(--border);
}
.ai-progress-header i { color: var(--accent); margin-right: var(--sp-1); }
.ai-progress-header::after {
  content: ''; position: absolute; left: 0; bottom: -1px; height: 2px;
  width: var(--ai-progress-pct, 0%); background: var(--accent);
  transition: width var(--transition);
}

/* ── Design Health Score pill + breakdown popover (topbar) ── */
.health-pill-wrap { position: relative; display: inline-flex; align-items: center; }
.health-breakdown {
  display: none; position: absolute; top: calc(100% + 6px); left: 0;
  background: var(--bg-modal); border: 1px solid var(--border);
  border-radius: var(--radius-md); box-shadow: var(--shadow-md);
  min-width: 240px; z-index: 50; padding: var(--sp-3) var(--sp-3_5); font-size: 12px;
}
.health-breakdown.is-open { display: block; animation: fadeIn 0.12s ease; }
.health-breakdown-row { display: flex; justify-content: space-between; gap: var(--sp-2_5); padding: 3px 0; color: var(--text-secondary); }
.health-breakdown-issue { display: flex; align-items: flex-start; gap: var(--sp-1_5); padding: var(--sp-1) 0; font-size: 11px; color: var(--text-muted); border-top: 1px solid var(--border); }
.health-breakdown-issue:first-of-type { border-top: none; margin-top: var(--sp-1); }

/* ── Zone setup inline (merged into Getting Started) ── */
.zone-setup-inline { margin-top: var(--sp-2_5); padding-top: var(--sp-2_5); border-top: 1px solid var(--border); }

/* ── AI Chat Panel ── */
.chat-panel {
  position: absolute; right: 0; top: 0; bottom: 0; width: 320px;
  background: var(--bg-sidebar); border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  transform: translateX(100%); transition: transform 0.22s ease;
  z-index: 360; box-shadow: -4px 0 20px rgba(0,0,0,0.3);
}
.chat-panel.open { transform: translateX(0); }
.chat-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 11px var(--sp-3_5); border-bottom: 1px solid var(--border); flex-shrink: 0;
  background: var(--bg-card);
}
.chat-messages {
  flex: 1; overflow-y: auto; padding: var(--sp-3); display: flex;
  flex-direction: column; gap: var(--sp-2);
}
.chat-messages::-webkit-scrollbar { width: 4px; }
.chat-messages::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 2px; }
@keyframes msgIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.chat-msg { display: flex; animation: msgIn 0.22s ease backwards; }
.chat-msg-user { justify-content: flex-end; animation-duration: 0.18s; }
.chat-msg-ai   { justify-content: flex-start; animation-duration: 0.25s; }
.chat-bubble {
  max-width: 85%; padding: var(--sp-2) var(--sp-3); border-radius: 10px;
  font-size: var(--text-sm); line-height: 1.55; word-break: break-word;
}
.chat-msg-user .chat-bubble { background: var(--accent); color: #fff; border-radius: 10px 10px 2px 10px; }
.chat-msg-ai   .chat-bubble { background: var(--bg-card); color: var(--text-primary); border-radius: 10px 10px 10px 2px; border: 1px solid var(--border); }
/* Lightweight Markdown rendered inside AI bubbles (see mdToSafeHtml in app.js).
   Kept compact on purpose — full `prose` rhythm is too tall for chat bubbles. */
.chat-msg-ai .chat-bubble strong { font-weight: 600; }
.chat-msg-ai .chat-bubble .cb-head { display: block; margin: var(--sp-1_5) 0 var(--sp-0_5); font-weight: 600; color: var(--text-primary); }
.chat-msg-ai .chat-bubble .cb-head:first-child { margin-top: 0; }
.chat-msg-ai .chat-bubble ul { margin: var(--sp-1) 0; padding-left: 18px; }
.chat-msg-ai .chat-bubble li { margin: var(--sp-px) 0; }
.chat-msg-ai .chat-bubble li::marker { color: var(--accent); }
.chat-msg-ai .chat-bubble code {
  font-family: var(--font-mono); font-size: 0.92em;
  background: rgba(255,255,255,0.07); border: 1px solid var(--border);
  border-radius: 4px; padding: 0 var(--sp-1);
}
/* Animated thinking dots */
.chat-thinking { display: flex; align-items: center; gap: var(--sp-1); padding: var(--sp-2_5) var(--sp-3_5); }
.chat-thinking span {
  width: 6px; height: 6px; border-radius: 50%; background: var(--text-muted);
  animation: chatDot 1.2s infinite ease-in-out;
}
.chat-thinking span:nth-child(2) { animation-delay: 0.2s; }
.chat-thinking span:nth-child(3) { animation-delay: 0.4s; }
@keyframes chatDot { 0%,80%,100% { transform: scale(0.7); opacity:0.4; } 40% { transform: scale(1); opacity:1; } }
.chat-input-row {
  display: flex; gap: var(--sp-1_5); padding: var(--sp-2_5) var(--sp-3);
  border-top: 1px solid var(--border); flex-shrink: 0; align-items: flex-end;
}
.chat-input {
  flex: 1; padding: 7px var(--sp-2_5); background: var(--bg-input);
  border: 1px solid var(--border-input); border-radius: var(--radius-md);
  color: var(--text-primary); font-size: var(--text-sm); font-family: var(--font);
  resize: none; line-height: 1.4;
}
.chat-input:focus { outline: none; border-color: var(--border-focus); }

/* ── Team Chat Panel ── */
.team-chat-panel {
  position: absolute; right: 0; top: 0; bottom: 0; width: 300px;
  background: var(--bg-sidebar); border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  transform: translateX(100%); transition: transform 0.22s ease;
  z-index: 24; box-shadow: -4px 0 20px rgba(0,0,0,0.3);
}
.team-chat-panel.open { transform: translateX(0); }
.tc-msg {
  display: flex; gap: var(--sp-2); align-items: flex-start; padding: var(--sp-1) 0;
  animation: msgIn 0.22s ease backwards;
}
.tc-msg-own { flex-direction: row-reverse; }
.tc-avatar {
  width: 26px; height: 26px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: var(--text-xs); font-weight: 700; color: #fff;
}
.tc-bubble-wrap { max-width: 80%; display: flex; flex-direction: column; gap: var(--sp-0_5); }
.tc-msg-own .tc-bubble-wrap { align-items: flex-end; }
.tc-meta { display: flex; gap: var(--sp-1_5); align-items: baseline; }
.tc-name { font-size: var(--text-xs); font-weight: 600; color: var(--text-secondary); }
.tc-time { font-size: var(--text-2xs); color: var(--text-muted); }
.tc-bubble {
  font-size: var(--text-sm); line-height: 1.5; padding: 7px var(--sp-2_5);
  border-radius: 10px; word-break: break-word;
}
.tc-msg:not(.tc-msg-own) .tc-bubble {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 2px 10px 10px 10px; color: var(--text-primary);
}
.tc-msg-own .tc-bubble {
  background: #059669; color: #fff; border-radius: 10px 2px 10px 10px;
}
.tc-activity {
  font-size: var(--text-xs); color: var(--text-muted); text-align: center;
  padding: 3px 0; display: flex; align-items: center; justify-content: center; gap: var(--sp-1);
}
.tc-activity .ti { font-size: var(--text-xs); }
.team-chat-tabs {
  display: flex; flex-shrink: 0; border-bottom: 1px solid var(--border);
  background: var(--bg-card);
}
.team-chat-tab {
  flex: 1; padding: var(--sp-2) var(--sp-1); font-size: var(--text-xs); font-weight: 600;
  color: var(--text-muted); background: transparent; border: none;
  border-bottom: 2px solid transparent; margin-bottom: -1px;
  cursor: pointer; font-family: var(--font);
  display: flex; align-items: center; justify-content: center; gap: 5px;
  transition: color 0.15s, border-color 0.15s;
}
.team-chat-tab:hover { color: var(--text-secondary); }
.team-chat-tab.active { color: var(--text-primary); border-bottom-color: var(--accent); }
.team-chat-pane {
  display: flex; flex-direction: column; flex: 1; min-height: 0; overflow: hidden;
}
.btn-active { background: rgba(245,158,11,0.15) !important; }

/* ── Improved empty state ── */
.duct-list-empty {
  font-size: var(--text-xs); color: var(--text-muted); padding: var(--sp-4) var(--sp-2_5); text-align: center;
  background: rgba(255,255,255,0.02); border-radius: var(--radius-md);
  border: 1px dashed var(--border); line-height: 1.5;
}
.duct-empty-icon { font-size: 22px; display: block; margin-bottom: var(--sp-2); opacity: 0.5; }
.duct-empty-title { font-size: var(--text-sm); font-weight: 600; color: var(--text-secondary); margin-bottom: var(--sp-1); }
.duct-empty-sub { font-size: var(--text-2xs); line-height: 1.6; }

/* ── Equipment tabs ── */
.equip-tabs {
  display: flex; gap: 3px; margin-bottom: var(--sp-2);
  background: rgba(255,255,255,0.04); border-radius: var(--radius-md); padding: 3px;
}
.equip-tab {
  flex: 1; display: flex; align-items: center; justify-content: center; gap: var(--sp-1_5);
  padding: 7px var(--sp-2); border-radius: var(--radius-sm);
  font-size: var(--text-sm); font-weight: 500; cursor: pointer;
  background: transparent; color: var(--text-muted);
  border: none; transition: all var(--transition); font-family: var(--font);
}
.equip-tab i { font-size: var(--text-base); }
.equip-tab:hover { color: var(--text-primary); }
.equip-tab.active { background: var(--bg-card); color: var(--text-primary); box-shadow: 0 1px 3px rgba(0,0,0,0.25); }
.equip-panel-header { display: flex; gap: var(--sp-1_5); margin-bottom: 7px; align-items: center; }
.equip-panel-header .unit-search { flex: 1; margin-bottom: 0; }
.library-content { padding: var(--sp-2_5); display: flex; flex-direction: column; gap: 0; }

/* ── Workflow guide steps ── */
#workflowGuide { display: flex; flex-direction: column; }
.wf-step {
  display: flex; align-items: flex-start; gap: var(--sp-2_5);
  padding: var(--sp-2_5) 0; border-top: 1px solid var(--border);
}
.wf-step:first-child { border-top: none; padding-top: var(--sp-0_5); }
.wf-icon {
  width: 24px; height: 24px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; font-size: var(--text-sm); margin-top: var(--sp-px);
}
.wf-step.done   .wf-icon { background: rgba(34,197,94,0.14);  color: #22c55e; }
.wf-step.active .wf-icon { background: var(--accent-light);   color: var(--accent); }
.wf-step.pending .wf-icon { background: rgba(255,255,255,0.05); color: var(--text-muted); }
.wf-body { flex: 1; }
.wf-label { font-size: var(--text-sm); font-weight: 600; color: var(--text-primary); line-height: 1.3; }
.wf-step.pending .wf-label { color: var(--text-muted); }
.wf-sub { font-size: var(--text-2xs); color: var(--text-muted); margin-top: var(--sp-0_5); line-height: 1.4; }
.wf-step.done .wf-sub { color: rgba(34,197,94,0.75); }
.wf-btn {
  display: inline-flex; align-items: center; gap: 5px; margin-top: 7px;
  padding: 5px 11px; border-radius: var(--radius-sm);
  font-size: var(--text-xs); font-weight: 500; cursor: pointer;
  background: var(--accent-light); color: var(--accent);
  border: 1px solid rgba(59,130,246,0.3);
  transition: all var(--transition); font-family: var(--font);
}
.wf-btn:hover { background: rgba(59,130,246,0.2); box-shadow: 0 2px 8px rgba(59,130,246,0.15); }

/* ── Room chip tweak ── */
.room-chip { gap: var(--sp-1_5); padding: var(--sp-1) var(--sp-2_5); cursor: pointer; transition: background var(--transition), border-color var(--transition); }
.room-chip:hover { background: var(--bg-card-hover); border-color: var(--accent); color: var(--text-primary); }

/* ══════════════════════════════════════════════════════════
   MOBILE RESPONSIVE  (≤ 768 px)
   ══════════════════════════════════════════════════════════ */

/* Sidebar overlay backdrop — hidden by default */
#sidebarOverlay {
  display: none; position: fixed; inset: 0;
  background: rgba(0,0,0,0.55); z-index: 39;
}
#sidebarOverlay.active { display: block; }

/* Mobile sidebar toggle — hidden on desktop */
#mobileSidebarBtn { display: none; }

/* ── Mid-width: collapse topbar action buttons to icon-only ──────────────────
   Above the 768px mobile-kebab breakpoint but below full desktop, drop the
   button text labels and chevrons so the right cluster stays on one row and
   doesn't crowd the floor tabs / Search pill. The .btn-label / .btn-chevron
   wrappers exist precisely for this; tooltips (title=) carry the meaning. ── */
@media (min-width: 769px) and (max-width: 1180px) {
  .topbar-actions .btn-label,
  .topbar-actions .btn-chevron { display: none; }
  .topbar-actions .btn {
    padding: 5px var(--sp-2); gap: 0;
  }
}

@media (max-width: 768px) {

  /* ── Sidebar → off-canvas drawer ── */
  .sidebar {
    position: fixed; left: -100%; top: 0; bottom: 0;
    width: 86vw; max-width: 340px;
    z-index: 40; transition: left 0.25s ease;
    box-shadow: 4px 0 24px rgba(0,0,0,0.4);
  }
  .sidebar.mobile-open { left: 0; }
  /* A drawer should never be collapsed to a rail on mobile */
  .sidebar.collapsed { width: 86vw; max-width: 340px; }
  .sidebar.collapsed .sidebar-pane { display: flex !important; }
  .sidebar.collapsed .sidebar-tabs { flex-direction: row; }
  .sidebar.collapsed .sidebar-hint { display: flex; }
  .sidebar.collapsed .s-tab-label { display: inline; }

  /* Drawer header with close button */
  .sidebar-mobile-header {
    display: flex; align-items: center; justify-content: space-between;
    flex-shrink: 0; padding: var(--sp-2_5) var(--sp-3);
    border-bottom: 1px solid var(--border); background: var(--bg-sidebar);
  }
  .sidebar-mobile-title {
    display: flex; align-items: center; gap: 7px;
    font-size: var(--text-base); font-weight: 600; color: var(--text-secondary);
  }
  .sidebar-mobile-close {
    width: 36px; height: 36px; display: flex; align-items: center; justify-content: center;
    background: none; border: none; cursor: pointer;
    color: var(--text-muted); font-size: var(--text-2xl); border-radius: var(--radius-md);
  }
  .sidebar-mobile-close:active { background: rgba(255,255,255,0.08); color: var(--text-primary); }

  /* Collapse control is meaningless inside a drawer */
  .sidebar-collapse-btn { display: none; }

  /* Touch-friendly tabs */
  .sidebar-tab { padding: var(--sp-3_5) var(--sp-1); font-size: var(--text-base); }
  .sidebar-tab i { font-size: var(--text-2xl); }

  /* Show hamburger button */
  #mobileSidebarBtn { display: inline-flex; }

  /* ── Toolbar shell — anchor point for the dropdown sheet ── */
  .toolbar { position: relative; }

  /* ── Topbar — slim down ── */
  .topbar { padding: 0 var(--sp-2_5); gap: var(--sp-1_5); height: 48px; }
  /* While the actions menu is open, lift the whole topbar stacking context above
     the bottom toolbar dock + its sheet (55/56) so the dropdown — which extends
     down the screen — paints over the floating "Tools" pill instead of being
     covered by it. Scoped to the open state so the off-canvas sidebar drawer
     (z-index 40) still covers the resting topbar as before. */
  .topbar:has(#btnMobileMenu[aria-expanded="true"]) { z-index: 70; }
  .logo { font-size: var(--text-base); }
  .logo-word { font-size: var(--text-md); }
  .logo-mark { width: 24px; height: 24px; }
  .topbar-project-chip { display: none; }

  /* ── Floor tabs — kept (floor switching has no other mobile entry point), but
     constrained so 3+ tabs scroll horizontally inside the 46px bar instead of
     colliding with the kebab. Tabs don't shrink; scrollbar is hidden. ── */
  .floor-tabs {
    flex: 1 1 auto; min-width: 0; margin-left: var(--sp-1);
    overflow-x: auto; overflow-y: hidden;
    scrollbar-width: none; -webkit-overflow-scrolling: touch;
  }
  .floor-tabs::-webkit-scrollbar { display: none; }
  .floor-tab, .floor-tab-add { flex-shrink: 0; }

  /* ── Topbar actions — collapsed behind a kebab "⋯" trigger, opened as a
     dropdown menu instead of overflowing / scrolling off the right edge.
     Wired by ui-next.js + disclosure.js (same pattern as the tools sheet);
     ui-next.css adds the glass skin. ── */
  .topbar .topbar-menu-trigger { display: inline-flex; margin-left: auto; }
  .topbar-actions {
    flex-direction: column; gap: var(--sp-0_5);
    position: absolute; right: var(--sp-2_5); top: 100%;
    margin-top: var(--sp-1_5); width: 244px; max-height: 72vh; overflow-y: auto;
    background: var(--bg-modal); border: 1px solid var(--border);
    border-radius: var(--radius-md); box-shadow: var(--shadow-md);
    padding: var(--sp-1_5); z-index: 56;
  }
  .topbar-actions[hidden] { display: none; }

  /* The floating canvas overlays (active-tool pill, "did you know" hint) sit at
     z-index 100 — above the dropdown menus — and the tool pill is
     pointer-events:none, so it visibly punches through an open menu. Hide them
     while either mobile menu is open. */
  body:has(#btnMobileMenu[aria-expanded="true"]) .canvas-tool-pill,
  body:has(#btnMobileMenu[aria-expanded="true"]) .canvas-hint,
  body:has(#btnMobileTools[aria-expanded="true"]) .canvas-tool-pill,
  body:has(#btnMobileTools[aria-expanded="true"]) .canvas-hint { display: none; }

  /* Each top-level action fills the row; the dropdown wrappers must not clip. */
  .topbar-actions > .btn,
  .topbar-actions > .btn-icon,
  .topbar-actions .export-dropdown-wrap,
  .topbar-actions .user-menu-wrap { width: 100%; }
  .topbar-actions .btn,
  .topbar-actions .user-avatar-btn {
    width: 100%; justify-content: flex-start; min-height: 42px;
  }
  .topbar-actions .btn-icon { width: 100%; justify-content: flex-start; height: 42px; gap: 9px; }
  .topbar-actions .topbar-sep { display: none; }
  /* Reveal the text labels for the otherwise icon-only rows (Messages, Account)
     so every row in the dropdown reads as a labelled action, not a bare icon. */
  .topbar-actions .topbar-action-label { display: inline; }
  .topbar-actions .user-avatar-btn { gap: 9px; }

  /* Sub-menus (File/AI/Export/account…) flow inline as an accordion instead of
     absolute-positioning out of the scrolling sheet. */
  .topbar-actions .export-dropdown,
  .topbar-actions .user-dropdown {
    position: static; min-width: 0; width: 100%;
    margin: var(--sp-0_5) 0 var(--sp-1_5); box-shadow: none;
    background: var(--bg-card); border-radius: var(--radius-sm);
  }

  /* ── Toolbar — collapsed behind a "Tools" trigger, opened as a dropdown
     sheet (#toolbarRows) instead of horizontally-scrolling rows. Wired by
     ui-next.js + disclosure.js; this block is the layout, ui-next.css adds
     the glass skin. ── */
  .toolbar-mobile-trigger { display: flex; align-items: center; justify-content: center; height: 44px; }
  .toolbar-rows {
    display: flex; flex-direction: column; gap: var(--sp-1);
    position: absolute; left: var(--sp-2); right: var(--sp-2); top: 100%;
    margin-top: var(--sp-1_5); max-height: 60vh; overflow-y: auto;
    background: var(--bg-modal); border: 1px solid var(--border);
    border-radius: var(--radius-md); box-shadow: var(--shadow-md);
    padding: var(--sp-2); z-index: 56;
  }
  .toolbar-rows[hidden] { display: none; }

  /* Rows become uniform 3-column grids so tools line up instead of ragged
     wrapping. Structural separators (dividers, spacer) and the desktop mode
     caption are noise here — hide them. Groups/palette span the full width. */
  .toolbar-row {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: var(--sp-1_5); align-items: stretch;
    height: auto; padding: var(--sp-1) 0; overflow-x: visible;
  }
  .toolbar-row:nth-child(2) { margin-top: var(--sp-1); padding-top: var(--sp-2_5); border-top: 1px solid var(--border); }
  .toolbar-rows .tool-divider,
  .toolbar-rows .toolbar-spacer,
  .toolbar-rows #modeIndicatorLabel,
  .toolbar-rows .tool-label { display: none !important; }
  .toolbar-rows .btn { justify-content: flex-start; min-height: 42px; width: 100%; }
  .toolbar-rows #btn-select { grid-column: 1 / -1; justify-content: center; }
  .toolbar-rows .btn-group { grid-column: 1 / -1; display: grid !important; grid-template-columns: 1fr 1fr; gap: var(--sp-px); }
  .toolbar-rows .btn-group .btn { justify-content: center; }
  /* The plan/duct tool groups are inline-flex wrappers toggled show/hide via
     inline display:flex|none. Span them full width and lay their buttons out as
     a nested 3-col grid — matched only while shown so the hidden group stays
     hidden (its inline display:none has no "flex" to match). */
  .toolbar-rows #toolbar-plan-tools,
  .toolbar-rows #toolbar-duct-tools {
    grid-column: 1 / -1; grid-template-columns: repeat(3, 1fr); gap: var(--sp-1_5);
  }
  .toolbar-rows #toolbar-plan-tools[style*="flex"],
  .toolbar-rows #toolbar-duct-tools[style*="flex"] { display: grid !important; }
  .toolbar-rows #colorPalette { grid-column: 1 / -1; justify-content: center; gap: var(--sp-1_5); }
  .toolbar-rows .duct-width-select { grid-column: 1 / -1; width: 100% !important; min-height: 42px; }
  .btn { padding: 7px 9px; font-size: var(--text-sm); min-height: 44px; }
  .shortcut-hint { display: none; }
  /* Keyboard shortcut badges are dead weight on touch — no physical keyboard
     means they're not actionable, and they widen every button in the already
     horizontally-scrolling toolbar rows. */
  .btn kbd { display: none; }
  .btn-icon { width: 44px; height: 44px; font-size: var(--text-lg); }
  .tool-divider { height: 16px; margin: 0 3px; }
  .tool-label { display: none; }
  .duct-width-select { width: 82px; font-size: var(--text-xs); }

  /* ── Status bar — hide noisy items, keep Elements + zoom ── */
  .status-bar { height: 32px; padding: 0 var(--sp-2_5); }
  #statusSnap { display: none; }

  /* ── Touch targets — bump tiny in-panel controls to a ~44px hit area on touch
     (iOS HIG / Material minimum). Visual size of swatches is kept small via an
     inner box; the element box (and its padding) carries the larger tap region
     so layouts don't bloat. ── */
  .layer-vis-btn, .layer-lock-btn,
  .status-zoom-btn { min-width: 44px; min-height: 44px; }
  .color-swatch {
    width: 44px; height: 44px; padding: 13px;
    background-clip: content-box; box-sizing: border-box;
  }
  .duct-swatch { width: 44px; height: 44px; }

  /* ── Modals — full-width on small screens ── */
  .modal { padding: var(--sp-5) var(--sp-4); }
  .modal-title { font-size: var(--text-lg); }
  .settings-modal, .library-modal { max-width: 100%; }
  .theme-grid { grid-template-columns: repeat(3, 1fr); }
  .icon-grid  { grid-template-columns: repeat(6, 1fr); }

  /* ── Auth gate card ── */
  .auth-gate-card { padding: var(--sp-7) var(--sp-5); }

  /* ── Upload overlay box ── */
  .upload-box { padding: var(--sp-8) var(--sp-6); }

  /* ── Chat panel — full-width on mobile ── */
  .chat-panel { width: 100%; }

  /* ── Team chat panel — full-width on mobile (mirror .chat-panel) ── */
  .team-chat-panel { width: 100%; right: 0; left: 0; }

  /* ── iOS focus-zoom guard ──
     iOS Safari force-zooms the page whenever a focused text-entry field has a
     font-size below 16px. Every small editor input (.prop-input 12px,
     .unit-search 11px, .chat-input 12px, .api-key-input 12px, .duct-width-select
     11px …) trips this. Pin them all to 16px on touch widths only — desktop
     sizes (set elsewhere) are untouched. */
  input, select, textarea,
  .prop-input, .unit-search, .chat-input, .api-key-input,
  .duct-width-select, .cmd-input {
    font-size: 16px !important;
  }

  /* ── Toast — full-width at bottom ── */
  .toast-container { bottom: 60px; right: 10px; left: 10px; }
  .toast { max-width: 100%; }

  /* ── Canvas hint — span width below the centred tool pill ── */
  .canvas-hint { top: 54px; left: 10px; right: 10px; transform: translateY(-6px); max-width: none; font-size: var(--text-xs); }
  .canvas-hint.visible { transform: translateY(0); }

  /* ── Dropdowns — prevent clipping off right edge ── */
  .export-dropdown { right: auto; left: 0; }

  /* ── Collab "changes saved" banner — wrap-safe so long names don't overflow a
     narrow phone (was position:fixed + white-space:nowrap). Stays centred. ── */
  .collab-changes-banner {
    max-width: calc(100vw - 24px);
    white-space: normal;
  }
}

/* ── Context Menu ── */
.context-menu {
  position: fixed; z-index: 500; display: none;
  background: var(--bg-modal); border: 1px solid var(--border);
  border-radius: var(--radius-md); padding: var(--sp-1);
  box-shadow: var(--shadow-lg); min-width: 180px;
  animation: fadeIn 0.12s ease;
  user-select: none;
  max-height: calc(100vh - 16px); overflow-y: auto;
}
.context-menu.open { display: block; }
.context-menu-item {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: 7px var(--sp-2_5); font-size: var(--text-sm); font-weight: 500;
  color: var(--text-secondary); border-radius: var(--radius-sm);
  cursor: pointer; transition: all 0.1s ease;
  border: 1px solid transparent;
}
.context-menu-item i { font-size: var(--text-md); width: 16px; text-align: center; flex-shrink: 0; }
.context-menu-item .ctx-shortcut { margin-left: auto; font-size: var(--text-2xs); color: var(--text-muted); }
.context-menu-item:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); border-color: var(--border); }
.context-menu-item.danger { color: #f87171; }
.context-menu-item.danger:hover { background: rgba(239,68,68,0.08); border-color: rgba(239,68,68,0.2); }
.context-menu-separator { height: 1px; background: var(--border); margin: var(--sp-1) 0; }

/* ── Command Palette ── */
.cmd-palette-bg {
  position: fixed; inset: 0; z-index: 600;
  background: rgba(0,0,0,0.55); backdrop-filter: blur(4px);
  display: none; align-items: flex-start; justify-content: center;
  padding-top: 80px;
}
.cmd-palette-bg.open { display: flex; animation: fadeIn 0.15s ease; }
.cmd-palette {
  width: 100%; max-width: 520px; margin: 0 var(--sp-4);
  background: var(--bg-modal); border: 1px solid var(--border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.cmd-input-wrap {
  display: flex; align-items: center; gap: var(--sp-2_5);
  padding: var(--sp-3) var(--sp-3_5); border-bottom: 1px solid var(--border);
}
.cmd-input-wrap i { font-size: var(--text-xl); color: var(--text-muted); flex-shrink: 0; }
.cmd-input {
  flex: 1; background: transparent; border: none; outline: none;
  font-size: var(--text-md); color: var(--text-primary); font-family: var(--font);
}
.cmd-input::placeholder { color: var(--text-muted); }
.cmd-input-wrap .cmd-esc {
  font-size: var(--text-2xs); color: var(--text-muted); background: rgba(255,255,255,0.06);
  border: 1px solid var(--border); border-radius: 4px; padding: var(--sp-0_5) 5px; flex-shrink: 0;
}
.cmd-results { max-height: 340px; overflow-y: auto; padding: var(--sp-1); }
.cmd-result-item {
  display: flex; align-items: center; gap: var(--sp-2_5);
  padding: 9px var(--sp-2_5); border-radius: var(--radius-sm);
  cursor: pointer; font-size: var(--text-base); color: var(--text-secondary);
  border: 1px solid transparent; transition: all 0.1s ease;
}
.cmd-result-item i { font-size: var(--text-lg); width: 18px; text-align: center; flex-shrink: 0; }
.cmd-result-item .cmd-label { flex: 1; }
.cmd-result-item .cmd-shortcut { font-size: var(--text-2xs); color: var(--text-muted); flex-shrink: 0; }
.cmd-result-item:hover, .cmd-result-item.active {
  background: var(--accent-light); color: var(--text-primary); border-color: rgba(59,130,246,0.2);
}
.cmd-result-item.active i, .cmd-result-item:hover i { color: var(--accent); }
.cmd-group-label {
  font-size: var(--text-2xs); font-weight: 600; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 0.07em;
  padding: var(--sp-2) var(--sp-2_5) var(--sp-1);
}
.cmd-empty { padding: var(--sp-6); text-align: center; font-size: var(--text-base); color: var(--text-muted); }

/* ── Floating Properties Panel ── */
.floating-props-panel {
  position: fixed; z-index: 350;
  right: 16px; top: 108px;
  width: 252px;
  background: var(--bg-modal); border: 1px solid var(--border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow-lg);
  overflow: hidden; max-height: calc(100vh - 130px); overflow-y: auto;
  animation: fadeIn 0.15s ease;
  transition: right 0.22s ease;
}
/* Shift props panel left when team chat is open (300px panel + 16px gap) */
body.team-chat-open .floating-props-panel { right: 316px; }
.floating-props-handle {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--sp-2) var(--sp-2_5); cursor: move;
  background: rgba(255,255,255,0.03);
  border-bottom: 1px solid var(--border);
  user-select: none;
}
.floating-props-handle:hover { background: rgba(255,255,255,0.05); }

/* ── Dashboard team management rows ─────────────────────────────────────── */
.dash-team-row {
  display: flex; align-items: center; gap: var(--sp-2_5);
  padding: 9px 0; border-bottom: 1px solid rgba(255,255,255,0.06);
}
.dash-team-row:last-child { border-bottom: none; }
.dash-team-avatar {
  width: 34px; height: 34px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: var(--text-base); font-weight: 700; color: #fff;
}
.dash-team-info { flex: 1; min-width: 0; }
.dash-team-name { font-size: var(--text-base); color: var(--text-primary, #f8fafc); font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.dash-team-role { font-size: var(--text-xs); color: var(--text-muted, #64748b); margin-top: var(--sp-px); }

/* ── Real-time Collaboration ─────────────────────────────────────────────── */
/* Floats just under the topbar, top-right of the canvas (rendered into
   #canvasArea, which is the absolute-positioning context like .canvas-hint). */
.collab-presence-bar {
  /* Floats top-right of the canvas, dropped well below the topbar so it clears
     the account avatar / user menu and reads as a canvas overlay rather than
     hugging the menu. z-index also stays below the topbar's stacking context
     (z-index 30) so an open dropdown still paints over the avatars. */
  position: absolute; top: 84px; right: 48px; z-index: 25;
  display: flex; align-items: center; gap: var(--sp-1);
  /* No pill chrome — a bg-modal pill blends into the topbar. The colored avatar
     circles float directly on the canvas, each with its own ring + shadow. */
  background: none; border: none; padding: 0; box-shadow: none;
  pointer-events: auto;
}
.collab-avatar {
  width: 34px; height: 34px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: var(--text-sm); font-weight: 700; color: #fff;
  border: 2px solid rgba(255,255,255,0.9); cursor: default;
  box-shadow: 0 2px 8px rgba(0,0,0,0.45);
  transition: transform 0.15s;
}
.collab-avatar:hover { transform: scale(1.12); }
.collab-avatar-active {
  border-color: #a78bfa;
  /* purple presence ring + a drop shadow so it lifts off the canvas */
  box-shadow: 0 0 0 2px rgba(167,139,250,0.3), 0 2px 8px rgba(0,0,0,0.45);
}
.collab-avatar-typing {
  animation: collab-pulse 1s ease-in-out infinite;
}
@keyframes collab-pulse {
  0%, 100% { box-shadow: 0 0 0 2px rgba(99,102,241,0.3); }
  50%       { box-shadow: 0 0 0 4px rgba(99,102,241,0.6); }
}

/* Changes-available banner */
.collab-changes-banner {
  position: fixed; top: 52px; left: 50%; transform: translateX(-50%);
  display: flex; align-items: center; gap: var(--sp-2_5);
  background: #1e1b4b; border: 1px solid #6366f1;
  border-radius: 10px; padding: var(--sp-2_5) var(--sp-4);
  font-size: var(--text-base); color: #e0e7ff;
  box-shadow: 0 4px 20px rgba(99,102,241,0.4);
  z-index: 4000; white-space: nowrap;
  animation: slideDown 0.25s ease;
}
.collab-changes-btn {
  padding: var(--sp-1) var(--sp-3); background: #6366f1; color: #fff;
  border: none; border-radius: 6px; font-size: var(--text-sm); font-weight: 600;
  cursor: pointer; transition: background 0.15s;
}
.collab-changes-btn:hover { background: #4f46e5; }
.collab-changes-close {
  background: none; border: none; color: #94a3b8;
  cursor: pointer; padding: var(--sp-0_5) var(--sp-1); font-size: var(--text-md);
  display: flex; align-items: center;
}
.collab-changes-close:hover { color: #e2e8f0; }

@keyframes slideDown {
  from { transform: translateX(-50%) translateY(-12px); opacity: 0; }
  to   { transform: translateX(-50%) translateY(0);     opacity: 1; }
}

/* Touch gestures belong to the canvas (in-app pan/pinch-zoom), not the page.
   touch-action:none must sit on the elements that actually receive the touch —
   the canvasArea and the Konva-generated canvases inside the stage div. */
#canvasArea,
#konvaStageDiv,
#konvaStageDiv canvas { touch-action: none; }

/* Read-only mode for viewer role */
body.nd-readonly #mainCanvas,
body.nd-readonly #konvaStageDiv { cursor: default !important; }
body.nd-readonly .toolbar .btn:not(#btnUndo):not(#btnRedo):not(#btnSnap):not(#btnRooms) {
  opacity: 0.4; pointer-events: none;
}
body.nd-readonly .toolbar .btn-icon:not(#btnUndo):not(#btnRedo) {
  opacity: 0.4; pointer-events: none;
}
body.nd-readonly #btnSelect { opacity: 1 !important; pointer-events: auto !important; }

/* Team modal collaborator list */
.team-collab-row {
  display: flex; align-items: center; gap: var(--sp-2_5);
  padding: var(--sp-2) 0; border-bottom: 1px solid rgba(255,255,255,0.06);
}
.team-collab-row:last-child { border-bottom: none; }
.team-collab-avatar {
  width: 32px; height: 32px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: var(--text-sm); font-weight: 700; color: #fff;
}
.team-collab-info { flex: 1; min-width: 0; }
.team-collab-name { font-size: var(--text-base); color: var(--text-primary, #f8fafc); font-weight: 500; }
.team-collab-role { font-size: var(--text-xs); color: var(--text-muted, #64748b); margin-top: var(--sp-px); }
.team-collab-pending {
  display: inline-block; font-size: var(--text-2xs); font-weight: 600;
  color: #f59e0b; background: rgba(245,158,11,0.1);
  border: 1px solid rgba(245,158,11,0.3);
  border-radius: 4px; padding: var(--sp-px) 5px; margin-left: var(--sp-1_5);
  vertical-align: middle;
}

/* ══════════════════════════════════════════════════════════════
   REFINED GRAPHITE — app shell: layered chrome, instrument type, motion
   (loaded last so it layers over the base component styles above)
   ══════════════════════════════════════════════════════════════ */

/* Chrome surfaces float on the L0 canvas shell with a crisp top-light edge */
.topbar { box-shadow: var(--edge-light), 0 1px 0 rgba(0,0,0,0.4); }
.toolbar { box-shadow: var(--edge-light); }

/* Side/library/property panels and modals read as raised material */
.sidebar { box-shadow: var(--edge-light); }
.floating-props-panel, .chat-panel { box-shadow: var(--shadow-lg); }
.modal { box-shadow: var(--shadow-lg); }

/* Instrument numerics — mono + tabular figures on data readouts.
   Numeric property inputs, status counters and zoom readout read like gauges. */
.prop-input[type="number"], .duct-width-select,
.status-value, .status-zoom-label {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: -0.01em;
}

/* One decisive accent: gradient underline on the active sidebar tab */
.sidebar-tab.active {
  border-bottom-color: transparent;
  background-image: var(--accent-line);
  background-repeat: no-repeat;
  background-position: bottom;
  background-size: 100% 2px;
}

/* Primary action buttons carry the milled top-light edge */
.btn.active, .btn-primary { box-shadow: var(--edge-light); }

/* Focus rings keyed to the signature accent */
.prop-input:focus, .duct-width-select:focus,
.api-key-input:focus, .unit-search:focus, .chat-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

/* Respect reduced-motion */
@media (prefers-reduced-motion: reduce) {
  .collab-avatar, .collab-avatar-typing { animation: none; transition: none; }
  .modal-bg.open .modal { animation: none; }
}