- From: fantasai via GitHub <noreply@w3.org>
- Date: Tue, 24 Mar 2026 20:32:20 +0000
- To: public-css-archive@w3.org
> In Grid-Lanes: We follow the spec's item grouping model without placement knowledge. Per the spec, items are grouped by span size. Since plum (2-row span) and blue (1-row span) have different spans, they end up in different item groups. I think this is an incorrect understanding of the spec? The spec says: > Track sizing can be optimized by aggregating items that have the same span size and placement into a single virtual item as follows: > 1. Separate all the grid items into item groups, according to the following properties: (span, placement, baseline group) > 2. For each item group, synthesize a virtual grid item ... determine the baselines of the virtual grid item by placing all of its items into a single hypothetical grid track and finding their shared baseline(s) and shims ... > 3. Place hypothetical copies of each virtual grid item into the grid axis tracks in every position that the item could potentially occupy, **and run the track sizing algorithm with those items**. The resulting track sizes are the grid lanes container’s track sizes. If I'm understanding correctly, you're not doing step three, which would be the equivalent of placing a blue-green synthesis into tracks 1 and 2, and a plum synthesis as spanning both tracks, *and then running track sizing, including baseline alignment*. You can't do baseline alignment when aggregating the virtual items and then not do it in the final sizing. -- GitHub Notification of comment by fantasai Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13530#issuecomment-4121175679 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Tuesday, 24 March 2026 20:32:21 UTC