Bug 297232 – REGRESSION (Safari 18.5): `@media print` does not work when nested

• Component: CSS
• Status: RESOLVED FIXED

[Jordan Pittman]

Created attachment 476359 [details]
Example document demonstrating the bug

If you print a page with the following in Safari you'll see that the div is still visible:

```html
<style>
  .hidden {
    @media print {
      display: none;
    }
  }
</style>
<div class="hidden">FAIL if visible on print</div>
```

This is *not* the case if the media query wraps the rules as this works:

```html
<style>
  .hidden {
    @media print {
      display: none;
    }
  }
</style>
<div class="hidden">FAIL if visible on print</div>
```

I haven't yet found a workaround that allows nesting to work here in Safari.

Tested on:
- macOS 15, macOS 26, iOS 18, iOS 26

- Safari 17.3–18.4 (works)
- Safari 18.5–18.6 (broken)
- Safari 26 and TP (broken)
- Webkit Nightly (broken)
- Firefox (works)
- Chrome (works)

[Jordan Pittman]

I meant to put the nightly/build archive version I tested which was the latest as of this bug report: 298509@main

[Jordan Pittman]

Whoops I typo'd the second one. The example file is correct though.

Was supposed to be this:
```html
<style>
  @media print {
    .hidden {
      display: none;
    }
  }
</style>
<div class="hidden">FAIL if visible on print</div>
```

[Alexey Proskuryakov]

Thank you for such detailed regression information, and the minimized test case!

[Radar WebKit Bug Importer]

<rdar://problem/158081814>

[Matthieu Dubet]

Pull request: https://github.com/WebKit/WebKit/pull/49387

[EWS]

Committed 298843@main (e001647e607b): <https://commits.webkit.org/298843@main>

Reviewed commits have been landed. Closing PR #49387 and removing active labels.