https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_grid_la...
I think Safari has it because the guy that wrote the spec now works at Apple. Not 100% sure of that, but seems that way.
The code is in Chromium, just nobody ever hit the GO button.
It would have been much cleaner to add "auto-span" utility to grid-column and grid-row that allow to define "overflow snapping" if items are larger than template definitions, with an option for grid-auto-flow to affect packing logic
This draft feels like it's solving a single use case by stacking presets over the grid api instead of exposing tools to achieve that use case
I’ve found that grids are a little easier to maintain a flat hierarchy and avoid complexity, but the downside is it also doesn’t modularize that well – you need to compose all the cells together, some of which probably should belong in a child “component”.