How to hide free columns right and left

[pajaro1966]

Sorry for the posting if I'm asking something obvious or if it was already discussed: I couldn't find any thread. And sorry for using non-technical terms. When I select real size in my browser there are two white free columns right and left of my pages' content (content = left TOC+ files' content + right TOC). Therefore the pages seems to have five columns:

The content is too small and if I increase the font size, (i) the left TOC (first) and (ii) the right TOC (later) both disappear.

(i)

(ii)

Is there any way to make those two extra columns right and left disappear? Well I don't know if they are columns or if the web pages only use a certain width of the canvas and there is blank space right and left as a result.
I'm creating a webste I want to use it in my lessons (Ancient Greek): those two blank areas steal too much space when projecting the website on the screen: if I increase the size my students can see the text better, but I cannot navigate the website so easily as before (the TOCs disappear). I would like to see the files' content and the TOCs right and left simultaneously.

Thanks in advance for your time and for this amazing platform.

Antonio

[pajaro1966]

Sorry for my question. Here are the answers:

#3692
https://squidfunk.github.io/mkdocs-material/setup/setting-up-navigation/#content-area-width****