within a discussion here (don’t remember where it was), an advice was given to restrict the width of the Post Content Block via the advanced tab and the size settings there, where wanted. Doing so, I am just struggling to have the post content centered then (e.g. if the header / Footer settings are globally set to a wider range, a more narrow content should be centered)
The simplest way is probably to set the max-width to, lets say, 800px, width to 100% and use
margin-left: auto and
margin-right: auto to make it centered.
what’s left open is to configure a “narrow content template” which still allows to have some elements (mainly divs or sections) full-width (e.g. to have full width background) on a individual post basis, while that narrow content template inserts any content to centered and narrow (e.g. 800px).
And the “normal” setting is still applied to other posts, e.g. via the index template, is not restricted and refers to the global settings for sections (e.g. as initially the 1.120px)