title: why to use 'html, body' for scrollTop instead of just 'html'
body: <p>I got a solution from stackoverflow to scroll to the top of the page like</p>
  
  <pre><code>$('html, body').animate({scrollTop: $("#page").offset().top}, 2000);
  </code></pre>
  
  <p>But I am not sure why to use 'html, body' for scrollTop instead of just 'html' ?</p>