Overleaf/services/web/public/stylesheets/components/tabs.less

.ol-tabs {
  // Overrides for nav.less
  .nav-tabs {
    border: 0!important;
    margin-bottom: 0;
    margin-top: -@line-height-computed; //- adjusted for portal-name
    padding: @padding-lg 0 @padding-md;
    text-align: center;
  }

  .nav-tabs > li {
    display: inline-block;
    float: none;
    a {
      border: 0;
      color: @link-color-alt;
      &:hover {
        background-color: transparent!important;
        border: 0!important;
        color: @link-hover-color-alt;
      }
    }
  }

  li.active > a {
    background-color: transparent!important;
    border: 0!important;
    border-bottom: 1px solid @accent-color-secondary!important;
    color: @accent-color-secondary!important;
    &:hover {
      border-bottom: 1px solid @accent-color-secondary!important;
      color: @accent-color-secondary!important;
    }
  }
  .tab-content:extend(.container) {
    background-color: transparent!important;
    border: none!important;
  }
}