title: position:sticky is not working
body: <p>I have this HTML code:</p>
  
  <pre><code>&lt;div class="header"&gt;
  &lt;div class="desc"&gt;Description&lt;/div&gt;
  &lt;div class="logo"&gt;&lt;img src=""/&gt;&lt;/div&gt;
  &lt;div class="navbar"&gt;&lt;/div&gt;&lt;/div&gt;
  </code></pre>
  
  <p>.header has a height of 150px. .navbar has a height of 20px. When the user scrolls, I want .navbar to stick at the top. So I went to the CSS and set position:sticky and top:0. But this didn't work. I initially thought that firefox is not supporting position:sticky, but that's not the case because I was able to see a working demo of it. I googled about it but found nothing helpful. Anyone knows why this is not working?</p>