"nav-tabs" stackable in Bootstrap 3 with the "old" look (Bootstrap 2)

gistfile1.less

.nav-tabs {
  &.nav-stacked {
    border-bottom: 0;
    > li {
      float: none;
      > a {
        margin-right: 0;
        border: 1px solid @nav-tabs-border-color;
        border-radius: 0;
        &:hover, &:focus {
          border-color: @nav-tabs-border-color;
          z-index: 2;
        }
      }
      &:first-child > a {
        .border-top-radius(@border-radius-base);
      }
      &:last-child > a {
        .border-bottom-radius(@border-radius-base);
      }
    }
    > li + li {
      margin-top: 0;
    }
  }
}