When I open an article the left third of the page has the OP's name and logo, the right third has a newsletter offer and the centre barely a third is the article I'm trying to read, which usually consists of just 5 or 6 words per line.  Can I adjust these proportions or remove the newsletter third completely?  My browser is 'Brave' but I've just tried it on 'Vivaldi' and it's the same.

Sounds like you browse on a desktop device/PC?

Have you tried varying the zoom factor for the site?

Using a big zoom (140%, 150%...) leads to "interesting results" on my device.

Currently edit box about 75% of the screen size and nothing to the right.

Can't tell whether you will see the same.

Why don't you post a screen shot and tell us the platform/system in use!