Bootstrap/site/assets/scss/_toc.scss

// stylelint-disable selector-max-combinators, selector-max-type, selector-max-compound-selectors

//
// Right side table of contents
//

.bd-toc {
  @supports (position: sticky) {
    position: sticky;
    top: 4rem;
    height: subtract(100vh, 4rem);
    overflow-y: auto;
  }
  order: 2;
  padding-top: 1.5rem;
  padding-bottom: 1.5rem;
  @include font-size(.875rem);

  nav {
    padding-left: 0;
    border-left: 1px solid #eee;

    ul {
      padding-left: 0;

      ul {
        padding-left: 1rem;
      }
    }

    a code {
      font: inherit;
    }

    li {
      display: block;

      ul li ul {
        padding-left: 1rem;
      }

      a {
        display: block;
        padding: .125rem 1.5rem;
        color: #77757a;

        &:hover {
          color: $blue;
          text-decoration: none;
        }
      }
    }
  }
}