.chunk-wrapper {
    display: flex;
    gap: 20px;
    min-height: calc(100vh - 120px);
  }
  .chunk-main {
    flex: 1;
    min-width: 0;
  }
  .chunk-sidebar {
    width: 320px;
    flex-shrink: 0;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 2px 6px rgba(0,0,0,0.03);
    display: flex;
    flex-direction: column;
    height: calc(100vh - 130px);
    position: sticky;
    top: 80px;
  }
  .sidebar-header {
    padding: 16px;
    border-bottom: 1px solid #edf2f7;
    background: #f8fafc;
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
  }
  /* 1024px 이하 반응형: 우측 사이드바가 오프캔버스(드로어)로 변환 */
  .resource-drawer-btn {
    display: none;
  }
  .resource-drawer-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 1040;
    opacity: 0;
    transition: opacity 0.3s ease;
  }
  .resource-drawer-overlay.is-active {
    display: block;
    opacity: 1;
  }
  .resource-drawer-close {
    display: none;
  }

  @media screen and (max-width: 1024px) {
    .chunk-wrapper {
      flex-direction: column;
      gap: 12px;
    }
    .resource-drawer-btn {
      display: inline-flex !important;
    }
    .resource-drawer-close {
      display: inline-flex !important;
    }
    .chunk-sidebar {
      position: fixed !important;
      top: 0 !important;
      right: 0 !important;
      width: 320px !important;
      max-width: 85vw !important;
      height: 100vh !important;
      z-index: 1050 !important;
      border-radius: 0 !important;
      box-shadow: -4px 0 20px rgba(0,0,0,0.18) !important;
      transform: translateX(100%);
      transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .chunk-sidebar.is-active {
      transform: translateX(0) !important;
    }
  }
  .sidebar-search {
    margin-top: 10px;
  }
  .sidebar-tree-container {
    flex: 1;
    overflow-y: auto;
    padding: 12px;
  }
  /* 다계층(N단) 재귀적 트리 아코디언 */
  .tree-folder-node {
    margin-bottom: 4px;
  }
  .tree-folder-header {
    font-size: 0.84rem;
    color: #334155;
    padding: 6px 8px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: transparent;
    transition: all 0.15s;
    user-select: none;
  }
  .tree-folder-header:hover {
    background: #f1f5f9;
    color: #0284c7;
  }
  .tree-folder-header.depth-0 {
    font-weight: 700;
    font-size: 0.88rem;
    color: #0f172a;
    background: #f8fafc;
    border: 1px solid #edf2f7;
    margin-bottom: 4px;
    padding: 8px 10px;
  }
  .tree-folder-header.depth-0:hover {
    background: #e2e8f0;
  }
  .tree-children-container {
    padding-left: 12px;
    margin-top: 2px;
    border-left: 2px solid #e2e8f0;
    margin-left: 8px;
  }
  .tree-sheet-item {
    font-size: 0.78rem;
    padding: 5px 8px;
    color: #64748b;
    border-radius: 4px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.15s;
    user-select: none;
    margin-bottom: 2px;
  }
  .tree-sheet-item:hover {
    background: #e0f2fe;
    color: #0369a1;
    font-weight: 600;
  }
  .tree-sheet-item.is-active {
    background: #0284c7 !important;
    color: #ffffff !important;
    font-weight: 700;
  }
  .book-count-badge {
    font-size: 0.70rem;
    font-weight: 600;
    background: #e2e8f0;
    color: #475569;
    padding: 1px 6px;
    border-radius: 10px;
  }
  /* 메인 컨텐츠 영역 */
  .chunk-header-box {
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.03);
  }
  .passage-box {
    background: #fdfbf7;
    border: 1px solid #f3e8d2;
    border-left: 4px solid #d97706;
    border-radius: 8px;
    padding: 14px 18px;
    margin-bottom: 18px;
  }
  .passage-title {
    font-weight: 700;
    font-size: 0.85rem;
    color: #92400e;
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 6px;
  }
  .passage-content {
    font-size: 0.95rem;
    color: #451a03;
    line-height: 1.6;
    white-space: pre-wrap;
  }
  .chunk-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    overflow: hidden;
    box-shadow: 0 2px 6px rgba(0,0,0,0.03);
  }
  .chunk-table th {
    background: #f8fafc;
    color: #475569;
    font-weight: 700;
    font-size: 0.85rem;
    padding: 12px 14px;
    border-bottom: 1px solid #e2e8f0;
  }
  .chunk-table td {
    padding: 10px 12px;
    border-bottom: 1px solid #f1f5f9;
    vertical-align: middle;
  }
  .chunk-table tr:last-child td {
    border-bottom: none;
  }
  .chunk-table tr:hover {
    background-color: #fafbfc;
  }
  .btn-play-cell {
    width: 65px;
    padding: 0 !important;
    background: #f8fafc;
    border-right: 1px solid #e2e8f0;
    text-align: center;
  }
  .btn-play-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    min-height: 70px;
  }
  .btn-play-action {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background: #0284c7;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 5px rgba(2, 132, 199, 0.3);
  }
  .btn-play-action svg {
    display: block;
    margin: auto;
  }
  .btn-play-action:hover {
    background: #0369a1;
    transform: scale(1.1);
  }
  .btn-play-action.is-playing {
    background: #e11d48;
    box-shadow: 0 0 12px rgba(225, 29, 72, 0.6);
    animation: pulse 1.5s infinite;
  }
  @keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
  }
  .input-voca, .input-trans, .input-desc, .input-voca-word, .input-voca-trans, .input-voca-ex, .input-voca-ex-trans, .input-voca-emph, .input-voca-dict {
    width: 100%;
    display: block;
    box-sizing: border-box;
    resize: none;
    overflow-y: hidden;
    font-family: inherit;
    line-height: 1.45;
    min-height: 38px;
    transition: border-color 0.15s, box-shadow 0.15s;
  }
  .input-voca, .input-voca-word {
    font-size: 0.98rem;
    font-weight: 700;
    color: #0f172a;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    padding: 8px 10px;
    background: #ffffff;
  }
  .input-voca:focus, .input-voca-word:focus {
    border-color: #0284c7;
    outline: none;
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
  }
  .input-trans, .input-voca-trans {
    font-size: 0.88rem;
    font-weight: 500;
    color: #1d4ed8;
    border: 1px solid #dbeafe;
    border-radius: 6px;
    padding: 7px 10px;
    background: #eff6ff;
    margin-top: 6px;
  }
  .input-trans:focus, .input-voca-trans:focus {
    border-color: #2563eb;
    background: #ffffff;
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  }
  .input-desc, .input-voca-ex-trans {
    font-size: 0.82rem;
    font-weight: 500;
    color: #059669;
    border: 1px solid #a7f3d0;
    border-radius: 6px;
    padding: 6px 10px;
    background: #ecfdf5;
    margin-top: 6px;
  }
  .input-desc:focus, .input-voca-ex-trans:focus {
    border-color: #059669;
    background: #ffffff;
    outline: none;
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.15);
  }
  .input-voca-emph {
    font-size: 0.82rem;
    font-weight: 500;
    color: #be123c;
    border: 1px solid #fecdd3;
    border-radius: 6px;
    padding: 6px 10px;
    background: #fff1f2;
    margin-top: 6px;
    font-family: monospace;
  }
  .input-voca-emph:focus {
    border-color: #e11d48;
    background: #ffffff;
    outline: none;
    box-shadow: 0 0 0 3px rgba(225, 29, 72, 0.15);
  }
  .input-voca-ex {
    font-size: 0.88rem;
    font-weight: 500;
    color: #334155;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    padding: 7px 10px;
    background: #ffffff;
  }
  .input-voca-ex:focus {
    border-color: #0284c7;
    outline: none;
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
  }
  .input-voca-dict {
    font-size: 0.84rem;
    font-weight: 500;
    color: #475569;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    padding: 7px 10px;
    background: #ffffff;
    margin-top: 6px;
  }
  .input-voca-dict:focus {
    border-color: #64748b;
    background: #ffffff;
    outline: none;
    box-shadow: 0 0 0 3px rgba(100, 116, 139, 0.15);
  }
  /* 단어장 미리보기 카드 (수정 불가, 태그 렌더링) */
  .vocab-preview-box {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    padding: 10px 12px;
    min-height: 70px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 4px;
    user-select: text;
  }
  .vocab-preview-word {
    font-size: 1.05rem;
    font-weight: 700;
    color: #0f172a;
    line-height: 1.3;
  }
  .vocab-preview-word b, .vocab-preview-word strong {
    color: #e11d48;
    font-weight: 800;
    text-decoration: underline;
    text-underline-offset: 3px;
  }
  .vocab-preview-trans {
    font-size: 0.85rem;
    font-weight: 500;
    color: #1e293b;
    line-height: 1.4;
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    margin-top: 2px;
  }
  .meaning-badge {
    background: #eff6ff;
    color: #1d4ed8;
    border: 1px solid #dbeafe;
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 0.78rem;
    font-weight: 600;
    display: inline-block;
  }
  .meaning-badge:first-child {
    background: #dbeafe;
    color: #1e40af;
    font-weight: 700;
  }
  .time-compact-box {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 95px;
    margin: 0 auto;
  }
  .time-row-item {
    display: flex;
    align-items: center;
    background: #f8fafc;
    border: 1px solid #cbd5e1;
    border-radius: 5px;
    padding: 2px 5px;
  }
  .time-lbl {
    font-size: 0.70rem;
    font-weight: 700;
    color: #64748b;
    width: 24px;
    text-align: center;
    user-select: none;
  }
  .input-time-compact {
    flex: 1;
    width: 100%;
    border: none;
    background: transparent;
    font-size: 0.78rem;
    font-weight: 600;
    color: #1e293b;
    font-family: monospace;
    text-align: right;
    padding: 0 2px;
  }
  .input-time-compact:focus {
    outline: none;
  }
  .btn-save-all-common {
    transition: all 0.2s;
  }
  .btn-save-all-common.is-dirty {
    background-color: #10b981 !important;
    border-color: #059669 !important;
    color: #ffffff !important;
    box-shadow: 0 2px 6px rgba(16, 185, 129, 0.4);
    transform: scale(1.03);
  }