Full Width Containers in Limited Width Parents

[team-community]

Hi all. I would like to have a flexible modern template with a full-width image:

Attention! I mean not only the very first picture, but ALL pictures in the article.

In this case, the image should not occupy the entire screen. But only the main content area.

With css I can only do this:

But the picture should not occupy the entire screen. There are sidebars. The image should only occupy 100% of the content area.
I have read this guide. And it only gives the image width of the entire page, not the main content.
Please tell me how to do it?