Re: [csswg-drafts] [css-grid-3][masonry] Baseline alignment in the masonry axis (#9530)

Minor followup on this point -- I tested & we are indeed good/consistent:

> <ydaniv> almaher: I think we want to be consistent with multicol
> <ydaniv> fantasai: we believe we need the same clarification in multicol
> <ydaniv> ... I think you'd expect the last one
> <ydaniv> almaher: I think that makes sense

Our resolution today does indeed agree with multicol.  [Here's a hacky multicol testcase that I just put together](https://www.software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0AAAA%0A%3Cdiv%20style%3D%22display%3A%20inline-block%3B%20border%3A%201px%20solid%20black%3B%20columns%3A2%3B%20max-height%3A%2080px%22%3E%0A%20%20%3Cdiv%20style%3D%22height%3A80px%3B%20font-size%3A%2010px%22%3EFirst%20column%3C%2Fdiv%3E%0A%20%20%3Cdiv%20style%3D%22height%3A1px%3Bfont-size%3A40px%3B%20border%3A%202px%20solid%20red%22%3ETall%3C%2Fdiv%3E%0A%20%20%3Cdiv%20style%3D%22font-size%3A%2020px%3Bborder%3A%202px%20solid%20lime%3B%22%3ELastChild%3C%2Fdiv%3E%0A%3C%2Fdiv%3E%0ABBB%0A), using an `inline-block` with baseline-alignment to expose the last-baseline of a multicol element, with an overflowing penultimate item with a far-down baseline that should be ignored in favor of the next sibling (which is the last thing in its column):

```html
<!DOCTYPE html>
AAA
<div style="display: inline-block; border: 1px solid black; columns:2; max-height: 80px">
  <div style="height:80px; font-size: 10px">First column</div>
  <div style="height:1px;font-size:40px; border: 2px solid red">Tall</div>
  <div style="font-size: 20px;border: 2px solid lime;">LastChild</div>
</div>
BBB
```


Chromium and Gecko agree that the lime element (the last child in column 2) establishes the baseline, **not** the red item (the child with the furthest-down baseline in column 2).  That agrees with the resolution here.

WebKit agrees, too, but has a bug - they use the baseline of the lime item as if there weren't any column-wrapping, I think.

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Received on Wednesday, 1 October 2025 16:00:42 UTC