If your viewport is >1600px wide you should see a small square gray button resembling a full-screen toggle in the bottom-right corner of the browser. Click it a

If your viewport is >1600px wide you should see a small square gray button resembling a full-screen toggle in the bottom-right corner of the browser. Click it and the max-width limit on content is reverted and fills the viewport width. Images: https://imgur.com/a/UMxtP61 https://imgur.com/a/UMxtP61