Hi, use only one ID then class name ! This is not SPPB issue. I had this same problem in Wordpress, Prestashop.

#ID-Name .Class-Name {...}

If I prescribe styles for the addon, then I specify the addonId, and so do I prescribe styles for the button for example? Which has its own id. btn-1611771621913 btnId is not triggered

The addon ID is automatically added to any code added to the addon's css field. Therefore, you do not need to type an ID in this field. Only class.

Tip: Use this field only for initial styling. Once you're satisfied with the result, move css code to a custom.css file. Since the code added to this field remains directly on the page, creating unnecessary garbage and problems with validation.

Hi, use only one ID then class name ! This is not SPPB issue. I had this same problem in Wordpress, Prestashop.

ID-Name .Class-Name {...}

I know that. I'm talking about something else.

!

Probably you made somewhere mistake. As Pavel said, class name is all you need. Then add into Page custom CSS.