Background image in main and header content background or in body background?

Hi there Virue community!

I’m experimenting with the background of my website https://www.mobitecture.com. I would like to use a background with a
horizontal line at the top and a vertical line at the left of the content. Both lines originate from the logo at the top left.

I have tried uploading an image in header content background and main content background. It displays well, but there is a small white space between the two areas so I tried to upload the background in the body background. This is the current situation and it works well, apart from the fact that the content “crosses the line” on the left.

I’m considering two options to resolve this. Can I shift the content to the right so that it doesn’t cross the line anymore? Or should I make the background in bold content wider than it is now (1200 px) so that it does not interfere with the text anymore? This means making the image wider than the content background, will this cause problems for the mobile version?

Thanks in advance!