How to completely hide lcCorrectResponse placeholders in DITA Learning Assessment Author view?

[Apollo102]

Hello,

I am trying to customize the authoring mode for DITA learning assessments to create a clearer user experience.
My goal is to completely hide the technical placeholders for elements like <lcCorrectResponse>, as I am using custom CSS badges to indicate the correct answers instead.

However, despite several attempts using Oxygen-specific CSS properties, the grey placeholder boxes with the text "LcCorrectResponse" remain visible (see attached screenshots).

Screenshot 2026-04-06 213238.png

What I have tried so far:
/* Attempting to hide the element and its placeholder content */
*[class~="lcInteractionBase-d/lcCorrectResponseBase"] {
   display: none !important;
   -oxy-display-tags: none !important;
   -oxy-show-placeholder: no !important;
   -oxy-placeholder-content: "" !important;
   visibility: hidden !important;
   height: 0px !important;
}

/* Also tried suppressing it via the parent interaction container */
*[class~="learningInteractionBase-d/lcInteractionBase"] {
   -oxy-show-placeholder: no !important;
}

The Result:
The grey boxes are still rendered in the Author view. It seems like the standard DITA framework CSS has a higher priority or there is a specific mechanism enforcing these placeholders for Learning interactions.

My Questions:
Is there a specific framework-level CSS property I need to override to stop these elements from occupying space and showing text?
Are these elements perhaps "required" by the DITA framework's logic in a way that prevents them from being hidden via simple CSS?
What is the recommended way to achieve a "WYSIWYG" look for Quiz interactions where technical markers are replaced by custom CSS :after content?

I am using Oxygen XML Editor 21 and 28.

Any help or pointers to the specific CSS rules in the built-in DITA framework would be greatly appreciated!

Best regards,
Mike

[Radu]

Hi Mike,

Oxygen 21 is in our end of life stage so we no longer maintain or provide support for it:
https://www.oxygenxml.com/eol.html

Coming back to your problem, if you right click over such an element in the Author view, you can choose in the contextual menu the "Inspect Styles" menu item. The styles inspector view which shows up should show you all the CSS styles associated to it and where they are defined in the CSSs.
In this case there are before(3) and before (2) styles which need to be overwritten from your CSS:

Screenshot 2026-04-07 at 10.53.34.png

https://www.oxygenxml.com/doc/versions/ ... heets.html

Regards,
Radu