Sunsanvil

I have the same, or very similar question.

I’d like for full width pages to be the full width of the screen, up to 4K in fact. ?? While TwentySixteen is responsive out of the box, there seems to be a “max” width to content pages and I cant for the life of me find the code which is setting that limit.

I dont know that 3.5.2 is “such an old” version. The instructions you link to indicate that the manual process I went through is all thats required when going from versions as old as 2.7.x.