bitwarden-desktop/src/scss/left-nav.scss

.left-nav {
  order: 1;
  display: flex;
  flex-direction: column;
  width: 22%;
  min-width: 175px;
  max-width: 250px;
  border-right: 1px solid #000000;
  flex-grow: 1;
  justify-content: space-between;

  @include themify($themes) {
    background-color: themed("backgroundColorAlt");
    border-right-color: themed("borderColor");
  }
}

.vault-filters {
  user-select: none;
  scrollbar-gutter: stable;
  padding: 10px 15px;
  overflow-x: hidden;
  overflow-y: auto;
  height: 100%;

  .filter {
    hr {
      margin: 1em 0 1em 0;
      @include themify($themes) {
        border-color: themed("hrColor");
      }
    }
  }
}

.filter-heading {
  display: flex;
  text-transform: uppercase;
  font-weight: normal;
  margin-bottom: 5px;
  align-items: center;
  padding-top: 5px;
  padding-bottom: 5px;

  * {
    @include themify($themes) {
      color: themed("headingColor");
    }
    font-size: $font-size-base;
  }

  button {
    @extend .no-btn;
    text-transform: uppercase;
  }

  button.add-button {
    margin-left: auto;
    margin-right: 5px;

    &:hover,
    &:focus {
      cursor: pointer;

      @include themify($themes) {
        color: themed("headingButtonHoverColor");
      }
    }
  }

  &.active {
    .filter-button {
      h2 {
        @include themify($themes) {
          color: themed("primaryColor");
        }
      }
    }
  }
}

.filter-options {
  word-break: break-all;
  padding: 0;
  list-style: none;
  margin: 0 0 15px 0;
  .nested-filter-options {
    list-style: none;
    margin-bottom: 0px;
  }
}

.filter-option {
  top: 8px;
  width: 1.1em;

  @include themify($themes) {
    color: themed("textColor");
  }

  &.active {
    > .filter-buttons {
      .toggle-button,
      .filter-button {
        @include themify($themes) {
          color: themed("primaryColor");
          font-weight: bold;
        }
      }
    }
  }
}

.filter-buttons {
  padding: 5px 0;
  display: flex;
  align-items: center;

  &:hover,
  &:focus {
    .edit-button {
      visibility: visible;
    }

    .toggle-button,
    .filter-button {
      @include themify($themes) {
        color: themed("primaryColor");
      }
    }
  }

  button {
    @extend .no-btn;
  }

  .edit-button {
    visibility: hidden;
    margin-left: 2px;

    @include themify($themes) {
      color: themed("headingButtonColor");
    }

    &:hover,
    &:focus {
      @include themify($themes) {
        color: themed("headingButtonHoverColor");
      }
    }
  }
}

.nav {
  height: 55px;
  width: 100%;
  display: flex;
  .btn {
    width: 100%;
    font-size: $font-size-base * 0.8;
    flex: 1;
    border: 0;
    border-radius: 0;
    padding-bottom: 4px;

    &:not(.active) {
      @include themify($themes) {
        background-color: themed("backgroundColorAlt");
      }
    }

    i {
      font-size: $font-size-base * 1.5;
      display: block;
      margin-bottom: 2px;
      text-align: center;
    }
  }
}

// Nested indentions
ul.filter-options {
  // Level 1
  .filter-option {
    > .filter-buttons {
      padding-left: 12px;
    }

    .filter-option {
      left: -4px;
    }

    &.active > .filter-buttons .filter-option {
      left: 11px;
    }
  }

  // Level 2
  .nested-filter-options .filter-option {
    > .filter-buttons {
      padding-left: 23px;
    }

    .filter-option {
      left: 7px;
    }

    &.active > span li {
      left: 22px;
    }
  }

  // Level 3
  ul ul li {
    > span {
      padding-left: 34px;
    }

    li {
      left: 18px;
    }

    &.active > span li {
      left: 33px;
    }
  }

  // Level 4
  ul ul ul li {
    > span {
      padding-left: 45px;
    }

    li {
      left: 29px;
    }

    &.active > span li {
      left: 44px;
    }
  }

  // Level 5
  ul ul ul ul li {
    > span {
      padding-left: 56px;
    }

    li {
      left: 40px;
    }

    &.active > span li {
      left: 55px;
    }
  }

  // Level 6
  ul ul ul ul ul li {
    > span {
      padding-left: 67px;
    }

    li {
      left: 51px;
    }

    &.active > span li {
      left: 66px;
    }
  }

  // Level 7
  ul ul ul ul ul ul li {
    > span {
      padding-left: 78px;
    }

    li {
      left: 62px;
    }

    &.active > span li {
      left: 77px;
    }
  }
}