.nav-left {
  box-sizing: border-box;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: 6px;
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 1px 5px 0 rgba(0, 0, 0, 0.12),
    0 3px 1px -2px rgba(0, 0, 0, 0.2);
  background-color: $white;

  $nav-left-padding: 1rem;
  $nav-left-icon-width: 2rem;
  $nav-left-padding-full: $nav-left-padding + $nav-left-icon-width;

  // list resets

  ul {
    margin: 0;
  }

  a {
    display: block;
    padding-left: $nav-left-padding-full;
    line-height: 95%;
    padding-top: 0.2rem;
    padding-bottom: 0.2rem;
    border-left: 3px solid transparent;
  }

  a.inline {
    display: inline;
    padding: 0px;
  }

  a.is-active,
  li.is-active > a {
    background-color: desaturate(lighten($link-color, 50%), 20%);
    border-left: 3px solid $link-color;
  }

  a.is-archived,
  li.is-archived > a {
    color: desaturate(lighten($link-color, 20%), 80%);
  }

  .nav-left-section {
    background-color: $gray-lighter;
    border-top: 1px solid $gray-light;
    & > a {
      font-size: 1.2rem;
      padding: 0.9rem;
      padding-left: $nav-left-padding;
      i {
        width: $nav-left-icon-width + 0.5rem;
        margin-left: -0.5rem;
        text-align: center;
      }
    }
    &.active {
      background-color: $white;
      padding-bottom: 1rem;
    }

    a.nav-left-close {
      font-size: 1rem;
      cursor: pointer; // to react to touch events
      i {
        width: auto;
      }
    }
  }

  .nav-left-section .nav-left-title {
    font-size: 1rem;
    padding-top: 0.4rem;
    padding-bottom: 0.4rem;
    padding-left: $nav-left-padding-full;
    font-weight: bold;
  }

  .nav-left-section .nav-left-back {
    font-size: 0.8rem;
  }

  .divider {
    display: block;
    color: $gray-darker;
    text-transform: uppercase;
    font-size: 0.7rem;
    padding-left: $nav-left-padding-full;
    margin-top: 1rem;
    border-left: 3px solid transparent;
  }

  .nav-left-section-link ~ .divider,
  .nav-left-list > li.divider:first-child {
    margin-top: 0;
  }

  .options {
    padding: 1rem 0;
    .lang {
      white-space: nowrap;
    }
    .lang a {
      display: inline;
      padding: 0rem;
    }
    .lang {
      padding-left: $nav-left-padding-full;
    }
    .lang .active {
      color: $black;
      text-decoration: none;
    }
  }

  // typgraphical hierarchy

  $hierarchy-shift-width: 0.7rem;

  ul ul ul a {
    padding-left: 1 * $hierarchy-shift-width + $nav-left-padding-full;
  }
  ul ul ul ul a {
    padding-left: 2 * $hierarchy-shift-width + $nav-left-padding-full;
  }
  ul ul ul ul ul a {
    padding-left: 3 * $hierarchy-shift-width + $nav-left-padding-full;
  }
  ul ul ul ul ul ul ul a {
    padding-left: 4 * $hierarchy-shift-width + $nav-left-padding-full;
  }
  ul ul ul ul ul ul ul ul a {
    padding-left: 5 * $hierarchy-shift-width + $nav-left-padding-full;
  }
  ul ul ul ul ul ul ul ul ul a {
    padding-left: 6 * $hierarchy-shift-width + $nav-left-padding-full;
  }
}
