Per Bugzilla 1240834 we are implementing subgrid because it is a critical improvement for many CSS Grid use-cases, and we should explicitly state our position as such.
Some additional background on subgrid:
- Smashing Magazine: CSS Grid Level 2: Here Comes Subgrid
- Rachel Andrew: Grid Level 2 and Subgrid
- Rachel Andrew: Why display: contents is not CSS Grid Layout subgrid
Related: Pull request 114
Labels: w3c