To create your own customized style design, 
copy over the css files from ./files to ./user_files 
you would like to edit.

CSS files starting with "Q" indicates that the syntax is of 
Qt CSS, which is in it's core quite similar to the usual CSS.
Documentation here: 
- https://doc.qt.io/qt-5/stylesheet-syntax.html

User edited themes should that is also customized will be saved
in this folder.