Bootstrap/site/assets/scss/_toc.scss

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

.bd-toc-wrap {
  @include media-breakpoint-up(lg) {
    @supports (position: sticky) {
      position: sticky;
      top: 5rem;
      right: 0;
      z-index: 2;
      height: subtract(100vh, 7rem);
      overflow-y: auto;
    }
  }
}

.bd-toc nav {
  @include font-size(.875rem);

  ul {
    padding-left: 0;
    list-style: none;

    ul {
      padding-left: 1rem;
      margin-top: .25rem;
    }
  }

  li {
    margin-bottom: .25rem;
  }

  a {
    color: inherit;
  }

  a:not(:hover) {
    text-decoration: none;
  }

  a code {
    font: inherit;
  }
}