After integration not only the CKEditor (iframe) has foundation implemented but also the parent CMS system (parent of iframe).
Everything in the CMS is now styled by foundation! I only want the CKEditor styled by foundation.
How to prevent that from happening?

Hey,
I am using the Foundation plugins. For some reason the plugins add /..../ckeditor/plugins/doksoft_foundation_advanced_blocks/style.css and //cdnjs.cloudflare.com/ajax/libs/foundation/5.5.0/css/foundation.min.css to the head of the sourrouding document instead of adding them to the head of the CKEDITOR iframe on CKEDITOR.replace.
This is annoying as is messes up the current page (e.g. the backend), as soon as the affected plugins are loaded.
This is unwanted behaviour. A CKEditor plugin does not need to change the complete Website CSS. In case of inline usage the CSS needs to be there anyways in order to get applied when no CKEditor is attached. In case of replace there is no need to add the CSS to the sourrounding document. Also CKEditor content CSS can be set with the CKEDITOR.config.contentsCss key either in config.js or on replace.