title: CSS border under/below list item
body: <p>I have a list for my navbar.  I want to have a border below the active li item, not just on the bottom.</p>
  
  <p>I've been able to add the border to the bottom using border-bottom, but again, it needs to be below the li element.  Any help would be appreciated.</p>
  
  <p>Here is my custom css so far, in addition to default Bootstrap navbar list:</p>
  
  <pre><code>.nav .active{
      border-bottom: 5px solid yellow;
  }
  </code></pre>
  
  <p>See below:</p>
  
  <p><img src="https://i.stack.imgur.com/ubBqA.png" alt="enter image description here"></p>