Works and doesn't spy me!

Ok

Отлично работает, то что искал

How can I export my custom styles? I need to copy them to other firefox profile, but the EXPORT button (in Stylus styles manager) does not work. Is there another quick way? Recreating them manually one-by-one will take too much time.

Works perfect for my theme customizations. Thank you!

Amazing alternative to modern Stylish. If your needing a tool to install custom CSS themes, this is the go-to extension.