How to remove the frame around the VK widget?

Question

css

Good day.
Tell me how you can remove the frame around the widget from the VKontakte community - https://vk.com/dev/Community
I tried to write in my CSS:

iframe #page_wrap .wcommunity_wrap:before {box-shadow:none !important;}

But it does not help, apparently due to the fact that it is loaded through an iframe.
There is nothing in the documentation about this either. Isn't it really impossible?
Now, with grief on the floor, I did it through overflow:hidden and a negative margin, but this is some kind of crooked crutch that I don’t like at all. Maybe there are more human ways?
Thanks in advance!

Answer 1

The question is removed, peeped on another site. It turns out the frame color is stored in color1 - Background color. I didn't specify it by default. If you write FFFFFF then the frame disappears.
Thanks to all!