CSS Grid can be used to stack elements
Stack elements easy with display:grid… although you can do the same thing with display:block; — BUT that’s not really what Stefan is doing in this article, instead it’s moving the elements out of the regular content flow and setting them to grid positions that you would have otherwise required absolute positioning to achieve.
I came across the article How to Stack Elements in CSS written by Sarah Dresner and learned that one could use
An excerpt from CSS Grid can be used to stack elementsdisplay: grid;
to stack element without setting any absolute positioning! 😲