Hello DavidR, hello Polonus,
Thanks! I'll check the CSS file issue with our technical team.
The https issue probably is indeed Avast-related: I don't seem to have any notice from Firefox when using another security tool.
As for the malicious code detected by Quttera, I don't really understand what the issue could be, since this is just a regular link to an article, but we'll take a look at it as well.
Again, thanks for your help !