Re: [csswg-drafts] [css-gaps-1] Gap intersection point definition might need updating for multi-col (#12084)

A potential way we could address this would be the following:

1. Tweak the language in [*-gap spec for flex](https://www.w3.org/TR/css-align-3/#gap-flex) so that we use the term [gutter](https://www.w3.org/TR/css-align-3/#gutter) like multicol and grid containers do.
    - Potentially to: 
       - When applied to the [main axis](https://www.w3.org/TR/css-flexbox-1/#main-axis) (e.g. [column-gap](https://www.w3.org/TR/css-align-3/#propdef-column-gap) in a row [flex container](https://www.w3.org/TR/css-flexbox-1/#flex-container)), indicates **the gutter** (as if an additional fixed-size margin were inserted between adjacent [flex items](https://www.w3.org/TR/css-flexbox-1/#flex-item) in a single line). When applied to the [cross axis](https://www.w3.org/TR/css-flexbox-1/#cross-axis) (e.g. [row-gap](https://www.w3.org/TR/css-align-3/#propdef-row-gap) in a row [flex container](https://www.w3.org/TR/css-flexbox-1/#flex-container)), indicates **the gutter** between adjacent [flex lines](https://www.w3.org/TR/css-flexbox-1/#flex-line).

2. Now we can update the [definition of a gap](https://drafts.csswg.org/css-gaps-1/#layout-painting) such that a gap will "end" when it is in contact with a multicol spanner, since a gutter will end at that same location.
    - New definition would be:
        - The center of an intersection between a gap and the start and end of the [gutter](https://www.w3.org/TR/css-align-3/#gutter).
        - The center of an intersection between gaps in different directions.

For the pictured multicol container (columns in green) with a spanner (blue) we'd have the pictured intersections:

<img width="1037" height="1030" alt="Image" src="https://github.com/user-attachments/assets/256a601c-2e48-4d2d-962f-91df4a4c05b5" />

 

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Received on Wednesday, 9 July 2025 21:11:54 UTC