Content column cut off Mobile version – Launch Website

Dear Support Team

Yesterday we had the launch of the new WEbsite: https://heilpraktiker-wittmann.de/
Now there is a problem in the following section in the mobile version: https://heilpraktiker-wittmann.de/#overview
> The last box is cut off on mobile: see screenshot mobile: https://heilpraktiker-wittmann.de/support/Box-Mobile202409.jpg

The funny thing is that we already had this problem in the edited version of the website (under a subdomain that is now no longer accessible): see https://kriesi.at/support/topic/content-column-cut-off-mobile-version/#post-1464807
I have not changed the script, except that I have set the max-width to 990px and the height to 850px:
@media only screen and (max-width: 990px) {
#cell-blue {
height: 850px;
}
}

I really don’t understand it at all. Could you please help me?
What can I do so that the dark blue box is also completely displayed in the mobile version?

Best regards, Diana