问标题元素的高度高于预期。

EN

    #books {
        margin-top: 4rem;
    }

    <div class="row">
      <div class="col-lg-10 col-lg-offset-1 well">
        <h1 class="text-center">Brian Jacques</h1>
        <h3 class="text-center"><i>The scribe who was an abbot to all his readers</i></h3>
        <figure class="figure col-lg-12">
          <div class="img-thumbnail col-lg-10 col-lg-offset-1">
            <img src="http://i1378.photobucket.com/albums/ah88/ejacobosaur/Brian%20Jacques%20Cartoonized_zpsz412eynr.jpg" class="img-responsive figure-img img-fluid" alt="Brian Jacques cartoon">
            <figcaption class="figure-caption text-center">Jacques smiling. A radiance that shines through his books. Painted by Derek Wehrwein. </figcaption>
          </div>
        </figure>
    
        <h2 class="text-center" id="books">Widely Known For
        </h2>
        <div class="row">
          <div class="col-lg-6 text-center">
            <a href="https://en.wikipedia.org/wiki/Redwall" class="btn btn-info btn-lg" role="button" target="_blank">Redwall</a>
          </div>
          <div class="col-lg-6 text-center">
            <a href="https://en.wikipedia.org/wiki/Castaways_of_the_Flying_Dutchman" class="btn btn-info btn-lg" role="button" target="_blank">Castaways of the Flying Dutchman</a>
          </div>
        </div>
        <blockquote>
      <p class="text-center lead"><em>"So here is my story, may it bring<br>Some smiles and a tear or so,<br>It happened once upon a time,<br>Far away, and long ago,<br>Outside the night wind keens and wails,<br>Come listen to me, the Teller of Tales!"</em></p>
      <footer class="text-center">Brian Jacques,<cite title="Lord Brocktree"> Lord Brocktree</cite></footer>

        </blockquote>
      </div>
    </div>