如何在导航栏中添加行分隔符？

Question

我需要在链接之间添加分隔符。从boostrap3组件中取出导航栏。试图使用border-left，但失败了。用这个简单的问题打破了我的大脑。非常感谢任何帮助。

.navbar-default {
    z-index: 2;
    text-transform: uppercase;
    background-color: #cb5a3d;
}
.navbar-default .navbar-nav li > a {
    margin-right: 100px;
    padding: 25px 0;
    color: #FFFFFF;
    font-family: "FiraSans-bold", sans-serif;
}
.navbar-default .navbar-nav li:first-child {
    margin-left: 100px;

<nav class="navbar navbar-default">
  <!-- Brand and toggle get grouped for better mobile display -->
  <div class="navbar-header">
    <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
  </div>

  <!-- Collect the nav links, forms, and other content for toggling -->
  <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
    <ul class="nav navbar-nav">
      <li><a href="#">о компании</a>
      </li>
      <li><a href="#">услуги</a>
      </li>
      <li><a href="#">новости</a>
      </li>
      <li><a href="#">полезная информация</a>
      </li>
      <li><a href="#">контакты</a>
      </li>
    </ul>
  </div>
  <!-- end navbar-collapse -->
</nav>
<!-- end navbar -->