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