Re: [csswg-drafts] [css-sizing] Intrinsic sizes for stretchable replaced elements (#13149)

(also a meta-point your testcase should really use a width > 300px how distinguish between implementations using the default natural-size, and the stretch size, see WebKit at 400px).

Thanks for the discussion so far.

> I don't like that min/max-content get different behaviors depending on the property.

I think this depends on perspective. To me they have the same behaviour for each property - its just if it <ins>failed to produce a size at all</ins>, we have to give it some size - and the fallback for the stretchable replaced elements is to just stretch to the container if possible[1].

It's weird but thats what we have from a web-compat perspective at the moment (I would much prefer that these stretchable replaced elements had saner behaviour, but thats not the web we live in).

We also have to keep in mind also that you can `calc-size()` these sizes now so you can observe when these values resolve.

> There are also a bunch of specs that refer to these sizes

Yeah and this is why I want to avoid special auto behaviour, auto resolves to either fit-content or stretch.

From:

> if the automatic size has a special intrinsic contribution different

E.g. having these two cases being different would be bad:
```
<div style="width: min-content">
  <svg style="width: auto"></svg>
</div>
<div style="width: min-content">
  <svg style="width: min-content"></svg>
</div>
```

I think chrome may have had proposal 2-ish[2] in M138 (last year), but changed it as it was incorrect for `calc-size`.

[1] The fallback logic currently is actually:
 - Stretch to the container if definite.
 - If we have a percentage use the 300px - for web-compat reasons (yay) - https://www.software.hixie.ch/utilities/js/live-dom-viewer/?saved=14625
 - Otherwise 0px.

[2] We were resolving more than stretch for min-content. We'd still need a "last-resort" size for min/max content contributions.

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Received on Monday, 30 March 2026 23:25:22 UTC