[Bug]: *Start upgrade* of web update is unreadable on hover

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Initial	Hover

Steps to reproduce

1. Have Nextcloud set up
2. Bump the version of an app in info.xml
3. Open Nextcloud

Expected behavior

Start update is still readable when I hover

Installation method

None

Nextcloud Server version

28

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

No file, test, or entry point is named. Reproduce the issue by bumping an app version in info.xml and opening Nextcloud 28, then inspect the web update control and its hover styling. Done means the “Start update” text remains readable while hovered.