Steps to replicate the issue (include links if applicable):

• Create a text input element inside a field to be able to display messages.
• Display a toggle button outside of the field.
• Trigger a message, that shows up below the input field.

What happens?:
The button changes its height.

What should have happened instead?:
The button should not change its height.

Software version (skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):
Example code: https://gerrit.wikimedia.org/r/c/mediawiki/extensions/FileImporter/+/965769/