Is it possible to control styles of Google maps inserted via IFrame?

Question

Google Maps

There is a test site test.savageworld.ru . It has a map from Google maps inserted via Iframe.
For the second day I have been trying to influence the styles of GoogleMaps through CSS. But the card is not responding.
The problem is that on an Ipad with a retina, the window with the list of cities goes beyond the map, and the scroll disappears. It turns out that some cities are inaccessible.
The style that "featurelist-pane" is trying to affect.
I understand it's better to use the API rather than a simple map from My Places. But the end goal is easy map editing, adding new areas. And this will not be done by me, but by a person who is poorly versed in computers. It just so happened.
Is there any way to make changes to such a map? Or are they simply not available?
Thanks in advance!

Answer 1

I don’t know how much it will help: Making Google maps “for yourself” from Ruseller. There is also a link to the API from Google.