Custom CSS foes

Hello Sal and thanks for the reply

I tried the following:

systemctl stop zammad
systemctl stop zammad-web
vi /opt/zammad/app/assets/stylesheets/custom/custom.css
zammad run rake assets:precompile
systemctl start zammad
systemctl start zammad-web

This is the content of my custom.css

.login {
    background: #ff00ff;
}

Maybe I am writing something wrong in the CSS, since it completely borks the website
Could you share a part of your custom.css to see if it is me who is doing something wrong?

Thanks