Re: [csswg-drafts] [css-fonts-5] Feature for making text always fit the width of its parent (#2528)

Hey all, thank you for working on this!

I'm a web performance guy from Shopify. We released a new default theme earlier this year which uses a _Jumbo Text_ component. It uniformly grows a `font-size` of a multiline text without any of the lines overflowing. It currently uses JavaScript to achieve that, so after @argyleink told us about this feature, I was eager to give it a try.

I rebuilt a simple example [in this Codepen](https://codepen.io/krzksz-the-decoder/pen/RNavprd): 

<img width="1203" height="713" alt="Image" src="https://github.com/user-attachments/assets/b4464564-4215-4686-a204-0ff6c946ace7" />

The native version doesn't look right. I thought this may be because of the extra styling (our users can choose custom text alignment, per-line animations, etc.), but there seem to be some containment and alignment issues in the implementation itself.

For now, my feedback is that:

1. We're very supportive of this and would like to implement it with a graceful fallback to our JS-based solution.
2. We need to be able to trust that the `text-align`, `text-box`, and overall box containment behaves consistently.
3. In the real world implementation, we have `inline-flex` wrappers around each text line so we can't do `font-grow: consistent` unless we rebuild the component. It would be great if the algorithm could just target all `inline` descendants, not just direct children.

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Received on Wednesday, 10 December 2025 10:39:48 UTC