:root{
    --bg:#f5f7fb; --surface:#ffffff; --surface-2:#f0f2f8;
    --text:#1a1d29; --text-muted:#6b7280; --border:#e5e7eb;
    --primary:#6366f1; --primary-hover:#4f46e5; --primary-soft:#eef2ff;
    --success:#10b981; --danger:#ef4444; --warning:#f59e0b;
    --shadow-sm:0 1px 2px rgba(0,0,0,.05);
    --shadow:0 4px 12px rgba(0,0,0,.08);
    --shadow-lg:0 10px 30px rgba(0,0,0,.12);
    --radius:12px; --radius-sm:8px; --radius-lg:16px;
    --sidebar-w:320px;
  }
  [data-theme="dark"]{
    --bg:#0f1117; --surface:#1a1d29; --surface-2:#242836;
    --text:#f1f3f9; --text-muted:#9ca3af; --border:#2d3142;
    --primary:#818cf8; --primary-hover:#a5b4fc; --primary-soft:#1e1b4b;
    --shadow-sm:0 1px 2px rgba(0,0,0,.3);
    --shadow:0 4px 12px rgba(0,0,0,.4);
    --shadow-lg:0 10px 30px rgba(0,0,0,.5);
  }
  [data-theme="dim"]{
    --bg:#d1d5db; --surface:#e5e7eb; --surface-2:#f3f4f6;
    --text:#1f2937; --text-muted:#4b5563; --border:#9ca3af;
  }
  [data-theme="yellow"]{
    --bg:#fef3c7; --surface:#fffbeb; --surface-2:#fefce8;
    --text:#451a03; --text-muted:#78350f; --border:#fde68a;
  }
  [data-theme="bright"]{
    --bg:#ffffff; --surface:#ffffff; --surface-2:#f9fafb;
    --text:#000000; --text-muted:#4b5563; --border:#e5e7eb;
  }
  [data-theme="dim"] .preview-canvas-wrap { background-color: #d1d5db; }
  [data-theme="yellow"] .preview-canvas-wrap { background-color: #fef3c7; }
  [data-theme="bright"] .preview-canvas-wrap { background-color: #ffffff; }
  [data-theme="dark"] .preview-canvas-wrap { background-color: #121212; }
  [data-theme="dim"] canvas, [data-theme="yellow"] canvas { mix-blend-mode: multiply; }
  [data-theme="dark"] canvas { filter: invert(0.88) hue-rotate(180deg); }
  *{box-sizing:border-box;margin:0;padding:0}
  html,body{height:100%}
  body{
    font-family:'Inter',system-ui,-apple-system,sans-serif;
    background:var(--bg); color:var(--text);
    transition:background .3s,color .3s;
    overflow-x:hidden;
  }
  button,input,select,textarea{font-family:inherit;color:inherit}
  button{cursor:pointer;border:none;background:none}

  /* Layout */
  .app{display:grid;grid-template-columns:var(--sidebar-w) 1fr var(--sidebar-w);min-height:100vh}
  .sidebar{background:var(--surface);border-right:1px solid var(--border);padding:20px;overflow-y:auto;max-height:100vh;position:sticky;top:0}
  .sidebar.right{border-right:none;border-left:1px solid var(--border)}
  .main{padding:24px;overflow-y:auto;min-height:100vh}

  /* Header */
  .header{display:flex;align-items:center;justify-content:space-between;margin-bottom:20px;gap:12px;flex-wrap:wrap}
  .logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:18px}
  .logo-icon{width:36px;height:36px;background:linear-gradient(135deg,var(--primary),#8b5cf6);border-radius:10px;display:flex;align-items:center;justify-content:center;color:white;font-weight:700;box-shadow:var(--shadow)}
  .header-actions{display:flex;gap:8px;align-items:center}
  .icon-btn{width:40px;height:40px;border-radius:10px;background:var(--surface-2);display:flex;align-items:center;justify-content:center;transition:all .2s;color:var(--text)}
  .icon-btn:hover{background:var(--primary-soft);color:var(--primary)}
  .menu-btn{display:none}

  /* Cards */
  .card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px;margin-bottom:16px;box-shadow:var(--shadow-sm)}
  .card-title{font-size:14px;font-weight:600;margin-bottom:12px;display:flex;align-items:center;gap:8px;color:var(--text)}
  .card-title svg{width:16px;height:16px;color:var(--primary)}

  /* Upload zone */
  .upload-zone{border:2px dashed var(--border);border-radius:var(--radius-lg);padding:40px 20px;text-align:center;transition:all .3s;background:var(--surface);cursor:pointer}
  .upload-zone:hover,.upload-zone.drag{border-color:var(--primary);background:var(--primary-soft)}
  .upload-icon{width:64px;height:64px;margin:0 auto 16px;background:var(--primary-soft);border-radius:50%;display:flex;align-items:center;justify-content:center;color:var(--primary)}
  .upload-title{font-size:18px;font-weight:600;margin-bottom:6px}
  .upload-sub{color:var(--text-muted);font-size:14px;margin-bottom:16px}
  .btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 18px;border-radius:10px;font-weight:500;font-size:14px;transition:all .2s;border:1px solid transparent}
  .btn-primary{background:var(--primary);color:white}
  .btn-primary:hover{background:var(--primary-hover);transform:translateY(-1px);box-shadow:var(--shadow)}
  .btn-secondary{background:var(--surface-2);color:var(--text);border-color:var(--border)}
  .btn-secondary:hover{background:var(--border)}
  .btn-danger{background:var(--danger);color:white}
  .btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
  .btn-block{width:100%}
  .btn-group{display:flex;gap:8px;flex-wrap:wrap}

  /* File info */
  .file-info{display:none;padding:16px;background:var(--surface-2);border-radius:var(--radius);margin-top:16px}
  .file-info.show{display:block}
  .file-row{display:flex;justify-content:space-between;padding:6px 0;font-size:13px}
  .file-row span:first-child{color:var(--text-muted)}
  .file-row span:last-child{font-weight:500}

  /* Form controls */
  .field{margin-bottom:14px}
  .field-label{display:block;font-size:12px;font-weight:500;margin-bottom:6px;color:var(--text-muted);text-transform:uppercase;letter-spacing:.5px}
  .select,.input{width:100%;padding:9px 12px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--surface);font-size:14px;transition:border .2s}
  .select:focus,.input:focus{outline:none;border-color:var(--primary)}
  .slider-wrap{display:flex;align-items:center;gap:10px}
  .slider{flex:1;-webkit-appearance:none;height:6px;background:var(--surface-2);border-radius:3px;outline:none}
  .slider::-webkit-slider-thumb{-webkit-appearance:none;width:18px;height:18px;background:var(--primary);border-radius:50%;cursor:pointer;box-shadow:var(--shadow-sm)}
  .slider::-moz-range-thumb{width:18px;height:18px;background:var(--primary);border-radius:50%;cursor:pointer;border:none}
  .slider-val{min-width:44px;text-align:right;font-size:13px;font-weight:500;color:var(--primary)}

  .radio-group{display:flex;gap:6px;flex-wrap:wrap}
  .radio-pill{flex:1;min-width:70px}
  .radio-pill input{display:none}
  .radio-pill label{display:block;padding:8px;text-align:center;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:12px;cursor:pointer;transition:all .2s}
  .radio-pill input:checked + label{background:var(--primary);color:white;border-color:var(--primary)}

  .color-row{display:flex;gap:8px;align-items:center}
  .color-input{width:40px;height:36px;border:1px solid var(--border);border-radius:var(--radius-sm);padding:2px;background:var(--surface);cursor:pointer}

  .toggle-row{display:flex;gap:8px}
  .toggle-btn{flex:1;padding:8px;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:13px;background:var(--surface);transition:all .2s}
  .toggle-btn.active{background:var(--primary);color:white;border-color:var(--primary)}

  /* Collapsible */
  .collapsible-header{display:flex;align-items:center;justify-content:space-between;cursor:pointer;user-select:none;padding:4px 0}
  .collapsible-header .chev{transition:transform .2s}
  .collapsible-header.open .chev{transform:rotate(180deg)}
  .collapsible-body{max-height:0;overflow:hidden;transition:max-height .3s ease}
  .collapsible-body.open{max-height:2000px}

  /* Preview */
  .preview-wrap{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:20px;box-shadow:var(--shadow-sm)}
  .preview-toolbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px;gap:10px;flex-wrap:wrap}
  .preview-nav{display:flex;gap:6px;align-items:center}
  .preview-nav .page-ind{font-size:13px;font-weight:500;min-width:90px;text-align:center}
  .preview-canvas-wrap{display:flex;justify-content:center;align-items:center;min-height:300px;background:var(--surface-2);border-radius:var(--radius);padding:20px;overflow:auto}
  .preview-canvas-wrap canvas{max-width:100%;height:auto;box-shadow:var(--shadow-lg);border-radius:4px;background:white}
  .preview-empty{text-align:center;padding:60px 20px;color:var(--text-muted)}
  .preview-empty svg{width:64px;height:64px;margin-bottom:12px;opacity:.4}

  .thumbnails{display:flex;gap:8px;overflow-x:auto;padding:12px 0;margin-top:12px;border-top:1px solid var(--border)}
  .thumb{flex-shrink:0;width:80px;height:56px;border:2px solid var(--border);border-radius:6px;cursor:pointer;overflow:hidden;position:relative;background:white;transition:all .2s}
  .thumb:hover{border-color:var(--primary)}
  .thumb.active{border-color:var(--primary);box-shadow:0 0 0 2px var(--primary-soft)}
  .thumb canvas{width:100%;height:100%;object-fit:cover}
  .thumb-num{position:absolute;bottom:2px;right:2px;background:rgba(0,0,0,.7);color:white;font-size:10px;padding:1px 5px;border-radius:3px}

  /* Style presets */
  .preset-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}
  .preset{padding:12px;border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;transition:all .2s;text-align:center;background:var(--surface)}
  .preset:hover{border-color:var(--primary);transform:translateY(-1px)}
  .preset.active{background:var(--primary);color:white;border-color:var(--primary)}
  .preset-icon{font-size:22px;margin-bottom:4px}
  .preset-name{font-size:12px;font-weight:500}

  /* Progress */
  .progress{display:none;margin:16px 0}
  .progress.show{display:block}
  .progress-bar{height:6px;background:var(--surface-2);border-radius:3px;overflow:hidden}
  .progress-fill{height:100%;background:linear-gradient(90deg,var(--primary),#8b5cf6);width:0%;transition:width .3s}
  .progress-text{font-size:12px;color:var(--text-muted);margin-top:6px;text-align:center}

  /* Toast */
  .toast-wrap{position:fixed;bottom:20px;right:20px;z-index:1000;display:flex;flex-direction:column;gap:8px;pointer-events:none}
  .toast{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:12px 16px;box-shadow:var(--shadow-lg);display:flex;align-items:center;gap:10px;min-width:240px;animation:slideIn .3s;pointer-events:auto}
  .toast.success{border-left:4px solid var(--success)}
  .toast.error{border-left:4px solid var(--danger)}
  .toast.info{border-left:4px solid var(--primary)}
  @keyframes slideIn{from{transform:translateX(100%);opacity:0}to{transform:translateX(0);opacity:1}}

  /* Drawer overlay (mobile) */
  .drawer-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:90;opacity:0;transition:opacity .3s}
  .drawer-overlay.show{display:block;opacity:1}

  /* Print guide modal */
  .modal{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:100;align-items:center;justify-content:center;padding:20px}
  .modal.show{display:flex}
  .modal-content{background:var(--surface);border-radius:var(--radius-lg);padding:24px;max-width:500px;width:100%;max-height:90vh;overflow-y:auto;box-shadow:var(--shadow-lg)}
  .modal h3{margin-bottom:12px}
  .modal ul{margin:12px 0;padding-left:20px}
  .modal li{margin-bottom:6px;font-size:14px}

  /* Mobile */
  @media (max-width:1100px){
    .app{grid-template-columns:1fr}
    .sidebar{position:fixed;top:0;left:0;height:100vh;width:min(85vw,340px);z-index:95;transform:translateX(-100%);transition:transform .3s;box-shadow:var(--shadow-lg)}
    .sidebar.right{left:auto;right:0;transform:translateX(100%)}
    .sidebar.open{transform:translateX(0)}
    .menu-btn{display:flex}
    .main{padding:16px}
  }
  @media (max-width:500px){
    .upload-zone{padding:28px 14px}
    .preset-grid{grid-template-columns:1fr 1fr}
    .preview-toolbar{flex-direction:column;align-items:stretch}
    .preview-nav{justify-content:center}
  }

  /* Scrollbar */
  ::-webkit-scrollbar{width:8px;height:8px}
  ::-webkit-scrollbar-track{background:transparent}
  ::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}
  ::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}

  /* Formula editor */
  .formula-row{display:grid;grid-template-columns:80px 1fr;gap:8px;align-items:center;margin-bottom:8px}
  .formula-label{font-size:12px;font-weight:500;color:var(--text-muted)}
  .formula-input{font-family:'Courier New',monospace;font-size:13px}

  .badge{display:inline-block;padding:2px 8px;background:var(--primary-soft);color:var(--primary);border-radius:10px;font-size:11px;font-weight:500}