.book-menu nav ol {
  li {
    &.active {
      &::before {
        content: '⨎';
        color: var(--cl-blue);
      }
    }
  }
}
.toc {
  height: 100%;
  > ol {
    height: 90%;
    overflow: auto;
    position: relative;
    > li {
      font-weight: 500;
    }
  }
  > ol li {
    list-style: none;
  }
  > ol > li > ol {
    padding-bottom: 1rem;
    font-weight: 400;
  }
  ol {
    margin: 0;
    padding-left: 10px;
  }
  a {
    color: currentColor;
    height: 100%;
  }
  li::before {
    content: ' ';
    display: inline-block;
    height: inherit;
    left: 0;
    margin-top: -1px;
    position: absolute;
  }
  li:not(.active-parent) > .maybe-hide > li:not(.active) {
    height: 0;
  }
  li.active,
  li.active-parent,
  .maybe-hide li.active-parent,
  li.active-parent > .maybe-hide > li {
    height: auto;
  }
  ol li {
    padding: 0 0;
    line-height: 2;
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    a.toc-link {
      height: 100%;
    }
  }
  .label {
    font-size: 10px;
    font-weight: 700;
    display: block;
    color: var(--gray-600);
  }
  input[type='range'] {
    -webkit-appearance: none;
    margin: 18px 0;
    width: 100%;
  }
  input[type='range']:focus {
    outline: none;
  }
  input[type='range']::-webkit-slider-runnable-track {
    width: 100%;
    height: 2px;
    cursor: pointer;
    background: var(--cl-gray);
    border-radius: 1.3px;
  }
  input[type='range']::-webkit-slider-thumb {
    height: 16px;
    width: 16px;
    border-radius: 50%;
    background: var(--cl-blue);
    cursor: pointer;
    -webkit-appearance: none;
    margin-top: -7px;
  }
  input[type='range']::-moz-range-track {
    width: 100%;
    height: 2px;
    cursor: pointer;
    background: #444;
    border-radius: 1.3px;
  }
  input[type='range']::-moz-range-thumb {
    height: 16px;
    width: 16px;
    border-radius: 50%;
    background: var(--cl-blue);
    cursor: pointer;
    border: 0;
  }
}
