Struggling to make the content background transparent

This is the first website I have ever made and it’s coming along slowly but I’ve hit a snag. I don’t know how to make the content background (white part in the middle) transparent. I’d like the content in that box to be visible but for the white part to be transparent (for every page) so as the site background can be seen instead of the white.

I’ve tried copying and pasting various code snips into the custom css but nothing has worked so far.

My website is

Hello GrayJay,

This topic is already marked as Resolved.

Can you please confirm that you solved your issue?

Kind Regards, Roman.