Single Column Summary Grid Block

Hey Squarespace forums, wondering if anyone can help me with some advice or a bit of custom CSS.

For certain pages on my portfolio site, I've been using a summary grid block populated by a gallery to show off a set of videos, variously hosted on youtube/vimeo etc. (example: https://jordanblackdp.com/music-video) This has worked pretty well for me thus far, but I'm looking to switch up the formatting a bit and can't figure out how to do this within the built-in tools.

I would like the summary block to be a single column, with the images sized to fit across the entirety of the summary block. I have tried increasing the column width to the maximum of 600px, but on higher resolution displays this does not stretch wide enough to fill the window.

Any tips?

Thanks!

You mean on large screenshots, you want to fill up this space?

Thanks for your response!

Ideally, yes the page content would stretch to fit the window size, but more importantly, I'd like the page to be a single column with the thumbnail image for each video spanning the entirety of the site. It's a summary block in 'grid' mode sourcing content from a separate gallery.

Sorry if that's not a very clear explanation. I'll try to illustrate below.

Ultimately what I want is something that looks like this, with custom thumbnail images spanning the width of the site: https://jordanblackdp.com/new-page-layout-test

But the goal is for the page to function like this, with each image clickable and popping up into a fullscreen video: https://jordanblackdp.com/commercial

Let me know if that makes sense.