[Bug]: Left sidepane transparency on mobile web view should be less or not at all.

⚠️ 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

Left sidepane when you zoom in to much or go on mobile view has a transparency set when opened. With underlying objects it gets hard to read and see the actual menu.

See attached screenshot.

Steps to reproduce

1. minimize view or zoom in
2. open left sidepane
3. See it hovering over the file view.

Expected behavior

Less transparent background or solid background

Nextcloud Server version

30

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.3

Web server

Apache (supported)

Database engine version

MySQL

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

Fresh Nextcloud Server install

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

List of activated Apps

Nextcloud Signing status

none

Nextcloud Logs

Additional info

This can be seen on at least Nextcloud 30 and 31rc

Reproduce the issue in the mobile or zoomed web view on Nextcloud Server 30 or 31rc by opening the left sidepane over the file view. Trace the frontend entry point responsible for the sidepane appearance; done means the menu background is less transparent or solid and remains readable over underlying content.