Stylesheets
This program supports customization of the UI using .css
stylesheets. To switch between stylesheets, go to
Settings > Appearance.

Here, an example "dark mode" style has already been provided.
To add new stylesheets, simply add a .css file to the stylesheets
folder in /assets/stylesheets/. Then, either restart the program
or click "Reload Stylesheets."
More information on using stylesheets to customize ui elements can be found in Qt's documentation.