title: Menu bar with position fixed not working
body: <p>Menu bar is fixed on the top of the page while scrolling down. However, it is weird that while scrolling down, the menu bar goes under other div so I cannot click the menu.</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>#cssmenu {
    position: fixed;
    left: 0;
    top: 0;
    height: 40px;
    width: 100%;
    background-color: #E6E6E4;
  }
  
  .row {
    margin: 0 auto;
    width: 100%;
    height: 400px;
  }
  
  .col-sm-4 {
    height: 100%;
    border: 1px solid black;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id='cssmenu'&gt;
    &lt;ul class="menubar"&gt;
      &lt;li&gt;&lt;a href="#" class="btn btn-sm"&gt;Please&lt;/a&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#" class="btn btn-sm"&gt;Fix&lt;/a&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#" class="btn btn-sm"&gt;This&lt;/a&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#" class="btn btn-sm"&gt;Problem&lt;/a&gt;&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;
  &lt;div class="container-fluid"&gt;
    &lt;div class='row'&gt;
      &lt;div class="col-sm-4"&gt;&lt;/div&gt;
      &lt;div class="col-sm-4"&gt;&lt;/div&gt;
      &lt;div class="col-sm-4"&gt;&lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>This is the HTML code.</p>
  
  <p>It is weird that it works well with other div that are not using those classes(container-fluid and row). Please help me to fix this prlbem.</p>