My Changes Add-on
Using the My Changes add-on with your child theme is one of the recommended ways to manage CSS styles on a CS-Cart website. This prevents styles from being overwritten when CS-Cart is updated.
Navigate to Design > Templates > [Child Theme] > css > addons > my_changes and select the relevant stylesheet to edit.
Clear the Cache
In order to see your changes take effect, it's necessary to clear the cache. Navigate to Administration > Storage > Clear cache.