A few people have mentioned that it seems the author didn't realize this is already the 4th parameter in `box-shadow`, so I made a quick demo: https://codepen.io/gkoberger/pen/rNOommB
box-shadow: 0 18px 16px -15px rgba(0,0,0,0.3), 0 10px 10px -20px rgba(0,0,0,0.8);