Nothing happens with the css.append or css.prepend files

[kenvernaillenvub]

I have this in my 'config.js' file;
config.vendor.css.append.push('bower_components/sweetalert2/dist/sweetalert2.min.css');

Nothing happens.
When I looked into 'gulpfile.js', I noticed that vendor.css.append is never used in the gulp code.

What is the best way to add this already minified css file?

Thanks!

[fureszk]

+10000000
pretty annoying