This directory contains files specific to your theme customizations.

The custom-style.css file may include your custom CSS and CSS overrides. 
To enable this feature, copy and rename example.custom-style.css to 
custom-style.css or any other name, and configure the filename and path 
in the theme's settings page.

If Composer is used to update the theme (as recommended by Drupal), 
custom-style.css will be deleted. To prevent this, it is recommended to 
move the custom-style.css file to the Drupal themes folder or any other 
location on the web server.

Additionally, it is recommended to store any other custom files in this 
folder. Be sure to back up this folder to preserve your changes when 
upgrading to a new version of the theme.