When screen is reduced, the Call Out Tip box is broken

[MatheusFD]

Hi guys,

When browsing along the Plugin Guidelines, I reduced my screen to test the page and I found this issue.

Basically the issue is: when user reduce the page or access it via small screen, the Call Out Tip box, in the top, is broken.

Below you can see some images that shows the issue.

[coffee2code]

In 4497:

Handbook plugin: Fix responsive display of callout boxes at smaller widths, particular when sandwiched between sidebar and table of contents.

A more versatile solution will like be needed for edge cases.

Fixes #2208.