BLOG/CSS issue, default style overwritten and broke two column blog/sidebar

I have been tasked with rebuilding a broken site and have done pretty well until this problem,

SITE: https://happypea.ca

The blog (INSPIRATION in the menu) should be two columns but is only one with the sidebar under it instead of beside. I believe the CSS had been changed to make their front page work but ended up breaking the blog.

I just want to get it back to a nice two column WITHOUT breaking the front page. (their front page was built very unorthodox, as if it was a regular site, has class=”wrapper” for instance right in the body/text area of the front page)

I’m at a loss and ANY help would be greatly appreciated!

Cheers,
Brendan