Theme normal width and add listing without registration

Hello

I’m new to GD, after installation I faced the problem of giving full width ignoring my theme
I tried the compatibility plugin in the documentation, it is changing the style but still full width
also I tried some codes available on forums for CSS styling but still the same output!

one more thing, is there any way to allow adding listing with out login or at least creating the user with the addition of new listing in one click?

thank you

The page I need help with: [log in to see the link]