title: Issue with div background not spanning over entire section
body: <p>I am very new to HTML and CSS. I have a bunch of code in html that looks like the following:</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.content-section {
        background: #ffffff;
        padding: 10px 20px;
        border: 1px solid #dddddd;
        border-radius: 3px;
        margin-bottom: 20px;
      }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code> &lt;div class="content-section"&gt;
                  &lt;div class="media-body"&gt;
                      ...Media body
                  &lt;/div&gt;
              
          &lt;form&gt;
            ...Form
      
          &lt;/form&gt;
          &lt;br&gt;
          &lt;div&gt;
          ...
          &lt;/div&gt;
      
          &lt;div&gt;
            ...
          &lt;/div&gt;
      
          &lt;div&gt;
          ...
          &lt;/div&gt;
      
          &lt;div&gt;
  
          &lt;ul&gt;
          
          &lt;li&gt;...&lt;/li&gt;
          &lt;/ul&gt;
          &lt;/div&gt;
      
          &lt;div&gt;
          
          &lt;ul&gt;
          
          &lt;li&gt;...&lt;br&gt;&lt;/li&gt;
          &lt;/ul&gt;
          &lt;/div&gt;
      
      
          &lt;div&gt;
          &lt;ul&gt;
          ...
          &lt;/ul&gt;
          &lt;/div&gt;
      
          
      
      &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  <p>For some reason, the white background doesn't span over the entire section. I have list elements in my last div that go past the bottom of the white background.</p>