Overlapping Logo in Brine (Sonora) Footer

Site URL: https://www.tierratraveler.com/home

I am a novice attempting custom css... I followed Thirty Eight Visuals tutorial on 'adding an overlapping logo to your footer in Brine' and my logo is not showing up on the page. Curious if anyone can provide some guidance. Many thanks! The code provided is as follows:

.Footer {
  position: relative;
}
.Footer::before {
  background-image: url(https://static1.squarespace.com/static/5ced253de3cf090001e8017e/t/5d77a536f455f4647c54b991/1568122166263/Logo.png);
  background-size: contain;
  content: '';
  height: 100px;
  pointer-events: none;
  position: absolute;
  left: 50%;
  top: 0;
  transform: translate(-50%, -50%);
  width: 100px;
}

Can you take screenshot of an example? "'adding an overlapping logo to your footer in Brine"