Adapt Expand macro headings to browser window size

Issue Summary

This is reproducible on Data Center: (yes)

The long expand macro heading is not adapted to the smaller window size or appears to be cut off but the text underneath macro is wrapped correctly.

Steps to Reproduce

1. Create a new page and insert Expand Macro
2. Enter a Title. For example:

   Collaborative editing takes teamwork to the next level by letting you and your team work together in real time on software requirements, meeting notes, retros, and any other Confluence page. See who's editing the page with you, and see changes as they happen. Hit  to invite more people to edit with you.
   

3. Type or paste your text into the body of the macro. This content will be visible when someone clicks the macro title.
4. Choose Insert.
5. Add new title and save the page.

Expected Results

If the browser Window size is minimised then the long expand macro heading should be adapted to the window size.

Actual Results

If browser Window size is minimised then the long expand macro heading is not adapted to the window size or appears to be cut off but the text underneath macro is wrapped correctly.

If the browser Window size is normal/maximum then same behaviour is observed the smaller expand headings are displayed correctly but longer one are cut off but you can scroll towards right and read the heading which is not good user experience.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available