title: bootstrap how to appear scrollbar when reduce browser's size
body: <p>I'm using bootstrap 3.0 on the layout of my page.
  My HTML is something like:</p>
  
  <pre><code>&lt;html&gt;
      &lt;body&gt;
          &lt;div class="container"&gt;
              &lt;div class="row"&gt;
                  &lt;div class="col-md-12"&gt;&lt;/div&gt;
              &lt;/div&gt;
              &lt;div class="row"&gt;
                  &lt;div class="col-md-12"&gt;&lt;/div&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>When I tried to reduce my browser's size (IE/Chrome/Firefox). they shrink and overlapped. What I want is that having an horizontal scrollbar appear when the browser doesn't have enough width, which bootstrap container has a fixed width of 1170px.
  What css would I apply to achieve this goal?
  Thanks for any help!</p>