title: Bootstrap margin-bottom not working on small device
body: <p>I am new to bootstrap. I am having problem with nested rows where margin bottom does not seem to work on one of the sections. I am attaching a picture. There should be a gap between first and second div. It is working fine on big screen, it seem to break on small devices.</p>
  
  <p>Here is the code:
  CSS:</p>
  
  <pre><code>.row &gt; div {
      margin-bottom: 15px;
  }
  </code></pre>
  
  <p>HTML:</p>
  
  <pre><code>&lt;div class="row"&gt;
      &lt;div class="col-xs-12 col-sm-5 col-lg-5"&gt;
      &lt;div class="row"&gt;
          &lt;div class="col-xs-12 col-sm-12 col-lg-12"&gt;
              &lt;div class="col-xs-12 col-sm-6 col-lg-6"&gt;
                  &lt;div class="section"&gt;First div&lt;/div&gt;
              &lt;/div&gt;
  
              &lt;div class="col-xs-12 col-sm-6 col-lg-6"&gt;
                  &lt;div class="section"&gt;Second div&lt;/div&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  
      &lt;div class="col-xs-12 col-lg-12"&gt;
          &lt;div class="section"&gt;Third div&lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/3xAH2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3xAH2.png" alt="enter image description here"></a></p>