https://wpbrigade.com/docs/how-to-add-custom-css/
How to Add Custom CSS Classes to UCMM - WPBrigade
Apr 8, 2026 - Would you like to customize your UCMM pages? Learn to easily add custom CSS classes and styles to customize your under construction pages.
https://wordpress.org/support/plugin/image-custom-class/reviews/?filter=4
[Custom CSS classes for images] Reviews | WordPress.org