bootstrap 3：使导航栏链接下划线

Question

我正在开发一个 bootstrap 3 网站，我想在边框的帮助下为导航栏中的链接添加下划线，如下所示：

但目前看起来是这样的：

我尝试了“padding-bottom”属性，但没有任何效果。
我的html：

    <nav class="navbar navbar-default navbar-fixed-top">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand navbar-left" href="/index.html"><img class="nav-logo" src="/images/xcellent-logo/logo.png"></a>
    </div>
    <div id="navbar" class="navbar-collapse collapse">
      <ul class="nav navbar-nav nav-underline">
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Services<span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a href="stuff">stuff</a></li>
            <li><a  href="stuff">stuff</a></li>
            <li><a href="stuff">stuff</a></li>
            <li><a  href="stuff">stuff</a></li>
            <li><a  href="stuff">stuff</a></li>
          </ul>
        </li>
        <li><a  href="stuff">stuff</a></span></li>
        <li><a  href="stuff">stuff</a></span></li>
        <li><a  href="stuff">stuff</a></span></li>             
      </ul>
    </div><!--/.nav-collapse -->
  </div>
</nav>  

我尝试过的 CSS：

.nav-underline a {
border-bottom: transparent solid 2px;
padding-bottom: 40px;
}
.nav-underline a:hover {
border-bottom: $white solid 2px;
}

有没有办法做到这一点？感谢您的帮助！

Answer 1

只需将锚的填充移动到 li。这是自定义的CSS 一样。

.navbar-nav.nav-underline>li>a {
  padding: 0px;
}

.navbar-nav.nav-underline>li {
  padding: 15px;
}

下面是工作示例：

.nav-underline a {
  border-bottom: transparent solid 2px;
  padding-bottom: 40px;
}

.nav-underline a:hover {
  border-bottom: red solid 2px;
}

.navbar-nav.nav-underline>li>a {
  padding: 0px;
}

.navbar-nav.nav-underline>li {
  padding: 15px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />

<nav class="navbar navbar-default navbar-fixed-top">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand navbar-left" href="/index.html"><img class="nav-logo" src="/images/xcellent-logo/logo.png"></a>
    </div>
    <div id="navbar" class="navbar-collapse collapse">
      <ul class="nav navbar-nav nav-underline">
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Services<span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a href="stuff">stuff</a></li>
            <li><a href="stuff">stuff</a></li>
            <li><a href="stuff">stuff</a></li>
            <li><a href="stuff">stuff</a></li>
            <li><a href="stuff">stuff</a></li>
          </ul>
        </li>
        <li><a href="stuff">stuff</a></span>
        </li>
        <li><a href="stuff">stuff</a></span>
        </li>
        <li><a href="stuff">stuff</a></span>
        </li>
      </ul>
    </div>
    <!--/.nav-collapse -->
  </div>
</nav>