Fix styling of page preview

[MizukiTemma]

Short description

This PR fixes the styling of page preview.

Proposed changes

• Add a new css for page preview

Side effects

• None?

Resolved issues

Fixes: #3072

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Pull Request Review Guidelines

[charludo]

Can you recommend a page to test this on? 🙈 Both for the page Svenja linked in the issue and the pages I've tried in my local CMS environment, previews were already working in both FF and Chromium, so I am a bit confused 🙈

Not doubting the issue exists, just unsure how to test! ^^

[MizukiTemma]

@charludo
I have copied the source code of the referenced page, pasted it in the local environment and tried the preview with Chrome.

[JoeyStk]

Thank you very much!
I was able to reproduce this issue in both FF and Chromium, and it works for me with this PR :)

[charludo]

Thank you very much! I was able to reproduce this issue in both FF and Chromium, and it works for me with this PR :)

Strange! I am still unable to reproduce it, in any browser, and both in the dev environment and the test-cms.

Left is the page Svenja linked, right is the copy-pasted source code of that page in my local env on your branch. Already tried force-refreshing and deleting cache.

Anyways, since this apparently does its purpose for those thatare affected, and I can notice no negative impact, I'll simply approve 😄

[MizukiTemma]

@charludo
No negative efffect is also nice :)