title: Safari "position: fixed" is overlapped on scroll
body: <p>On Safari (Mac)** when I scroll on <a href="https://bhooks.com" rel="nofollow noreferrer">Bhooks.com</a>, the cards overlap the footer and the header of the webpage (with position: fixed). So far I'm unable to figure out why and I'm hoping to find some help here.</p>
  
  <p>I also upgraded Bootstrap to the latest version, just to make sure.</p>
  
  <p>Here's a screenshot of the issue:
  <a href="https://i.stack.imgur.com/JciWr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JciWr.png" alt="enter image description here"></a></p>
  
  <p>I know it's a very specific bug and I don't have a small minimal example (because developing on my Mac VM is a nightmare). But at least the problem is easily accessible and easy to debug.</p>
  
  <p>Thanks for your help!</p>
  
  <p>** in my case macOS mojave 10.14.3 with Safari 12.0.3</p>