:xpath(//main/div):style(min-width: 80% !important)
(I've been looking at going a step further for some sites, by annotating a "column-count:" [0] rule and making the screen look like a newspaper. (Narrow columns for readability—multiple columns for "scan-ability"). Unfortunately, there's a lot more fiddling and tuning to this than I expected: it doesn't automagically work in the way you'd hope. Modern website DOM layouts are basically Superfund sites).[0] https://developer.mozilla.org/en-US/docs/Web/CSS/column-coun...
[late edit]: Here's a minimal example of "column-count:" injected by uBlock (on a website where it sort-of works)—this is what I'm trying to coerce other websites into looking like:
https://i.ibb.co/k3bRwhP/example-1.webp
theguardian.com###maincontent:style(margin-left: -28vw !important; min-width: 90vw !important; column-count: 4 !important)
theguardian.com##div:style(border: none !important)(I really like the column idea, and I'm working back towards RSS, with a bunch of smart filters, being my primary way of interacting with anything I visit regularly. I never should have given it up).