I’m a huge fan of CSS Grid and I use it on pretty much every project these days. However, there’s one part of it that makes things much more complicated than they really ought to be: the lack of subgrids. And in this post on the matter, Ken Bellows explains why they’d be so gosh darn useful:
But one thing still missing from the Level 1 spec is the ability to create a subgrid, a grid-item with its own grid that aligns in one or both dimensions with the parent grid. It was originally planned to be in Level 1, but the working group decided they needed more time to work out the details, so it was removed, and it will ship in CSS Grid Layout Module Level 2, which seems to be nearing completion.
There has been a lot of discussion over the last 2 years about the use cases for subgrid, how it should be implemented, and even some debate over whether you even need it. A lot of that discussion was centered around two other approaches that can handle many of the same problems as subgrid: nested grids and display: contents
I remember one of the very first websites I worked on was much like the demo that Ken uses as an example, but this was way back in 2012 and grid didn’t exist yet. Sadly, I had to write a lot more CSS than I felt was necessary to get elements in one div to line up with elements in another. Anyway, this article kinda riffs off of Rachel Andrew’s post about subgrid and what problems it would help solve which is definitely worth checking out, too.