Login page styles are gone

Hello,

There have been no changes to the site in recent days for this to happen. The styles of the login page (standard wp login page) have disappeared. The folder contains a style file and a link to the styles on the page is indicated. However, the browser console persistently displays a 404 error that the file does not exist.

How can this be and why?

Reinstalling WordPress in the admin panel did not help fix the problem, installing a backup of earlier versions of the database also helped, disabling all plugins also did not reveal any problems where this was happening.