A Utility Class for Covering Elements

December 26th, 2020

Big ol’ same to Michelle Barker here:

Here’s something I find myself needing to do again and again in CSS: completely covering one element with another. It’s the same CSS every time: the first element (the one that needs to be covered) has position: relative applied to it. The second has position: absolute and is positioned so that all four sides align to the edges of the first element.

.original-element {
  position: relative;

.covering-element {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;

I have it stuck in my head somehow that it’s “not as reliable” to use bottom and right and that it’s safer to set the top and left then do width: 100% and height: 100%. But I can’t remember why anymore—maybe it was an older browser thing?

But speaking of modernizing things, my favorite bit from Michelle’s article is this:

.overlay {
  position: absolute;
  inset: 0;

The inset property is a Logical Property and clearly very handy here! Read the article for another trick involving CSS grid.

The original post A Utility Class for Covering Elements.