Dcat-Admin/resources/assets/sass/bootstrap-extended/mixins/_navs.scss

// Justified nav links
// -------------------------

@mixin nav-justified {
  width: 100%;

  .nav-item {
    float: none;
  }

  .nav-link {
    text-align: center;
    margin-bottom: 5px;
  }

  > .dropdown .dropdown-menu {
    top: auto;
    left: auto;
  }

  @include media-breakpoint-up(sm) {
    .nav-item {
      display: block;
      width: 1%;
    }
    .nav-link {
        margin-bottom: 0;
    }
  }
}

// Move borders to anchors instead of bottom of list
//
// Mixin for adding on top the shared `.nav-justified` styles for our tabs
@mixin nav-tabs-justified {

  .nav-link {
    // Override margin from .nav-tabs
    margin-right: 0;
    border-radius: $border-radius;
  }

  @include media-breakpoint-up(sm) {
   .nav-link.active,
   .nav-link.active:hover,
   .nav-link.active:focus {
      border-bottom-color: transparent;//$nav-tabs-justified-active-link-border-color;
    }
  }
}