Adding an accordion, issue with Safari

I love your theme: clean, efficient, essential.
Really.

But:
Here’s my website: https://www.maltabus.it/gianluca
I put an accordion (collapse-o-matic) for the infos under the header.

Ok with firefox.
Ok with Safari/mobile mode.
Ok with Safari/ipad mode

But in Safari laptop size, the accordion expand under the content.
Do you have any clue?

thank you