How to make a summary block always full-width even on large screens and when zoomed out.

I've got a website with a summary block on the home page. It's full width and in two columns, with the title visible in an overlay on hover. It looks fine on my screen and on mobile, but on larger screens (such as my client's) or when zooming out, the summary block doesn't remain full width. I've tried loads of variations of code, but can't seem to find the right one.

Thanks in advance!

Hi,

Can you share link to homepage?