lens/src/renderer/components/layout/sidebar.scss

.Sidebar {
  $iconSize: 24px;
  $activeBgc: $lensBlue;
  $activeTextColor: $sidebarActiveColor;
  $itemSpacing: floor($unit / 2.6) floor($unit / 1.6);

  @mixin activeLinkState {
    &.active {
      background: $activeBgc;
      color: $activeTextColor;
    }
    @media (hover: hover) { // only for devices supported "true" hover (with mouse or similar)
      &:hover {
        background: $activeBgc;
        color: $activeTextColor;
      }
    }
  }

  &.pinned {
    .sidebar-nav {
      overflow: auto;
    }
  }

  .header {
    background: $sidebarLogoBackground;
    padding: $padding / 2;
    height: var(--main-layout-header);

    a {
      font-size: 18.5px;
      text-decoration: none;
    }

    div.logo-text {
      position: absolute;
      left: 42px;
      top: 11px;
    }

    .logo-icon {
      width: 28px;
      height: 28px;
      margin-left: 2px;
      margin-top: 2px;
      margin-right: 10px;

      svg {
        --size: 28px;
        padding: 2px;
      }
    }

    .pin-icon {
      margin: auto;
      margin-right: $padding / 2;
    }
  }

  .sidebar-nav {
    padding: $padding / 1.5 0;

    .Icon {
      --size: #{$iconSize};

      box-sizing: content-box;
      padding: floor($padding / 2.6);
      border-radius: 50%;
    }

    .link-text {
      flex: 1;
      margin-left: $margin;
      overflow: hidden;
      text-overflow: ellipsis;
    }

    > a {
      @include activeLinkState;

      display: flex;
      align-items: center;
      text-decoration: none;
      border: none;
      padding: $itemSpacing;
    }

    hr {
      background-color: transparent;
    }
  }

  .SidebarNavItem {
    width: 100%;
    user-select: none;
    flex-shrink: 0;

    .nav-item {
      @include activeLinkState;

      cursor: pointer;
      width: inherit;
      display: flex;
      align-items: center;
      text-decoration: none;
      border: none;
      padding: $itemSpacing;
    }

    .expand-icon {
      --size: 20px;
    }

    .sub-menu {
      border-left: 4px solid transparent;

      &.active {
        border-left-color: $activeBgc;
      }

      a, .SidebarNavItem {
        display: block;
        border: none;
        text-decoration: none;
        color: $textColorPrimary;
        font-weight: normal;
        padding-left: 40px; // parent icon width
        overflow: hidden;
        text-overflow: ellipsis;
        line-height: 0px; // hidden by default
        max-height: 0px;
        opacity: 0;
        transition: 125ms line-height ease-out, 200ms 100ms opacity;

        &.visible {
          line-height: 28px;
          max-height: 1000px;
          opacity: 1;
        }

        &.active, &:hover {
          color: $sidebarSubmenuActiveColor;
        }
      }

      .sub-menu-parent {
        padding-left: 27px;
        font-weight: 500;

        .nav-item {
          &:hover {
            background: transparent;
          }
        }

        .sub-menu {
          a {
            padding-left: $padding * 3;
          }
        }
      }
    }
  }

  .loading {
    padding: $padding;
    text-align: center;
  }
}