How to change the width/height depending on the number of columns?

Question

css

I'm making a WordPress site and I'm wondering how to implement the following.
I can pin posts in the header, the width of each post is 33.333333%, regardless of how much is fixed, but I need the width to change. For example:
Pinned 1 post - 100%
Pinned 2 posts - each will be 50% wide.
3 posts are pinned - each will be 33.3% wide.
Etc.
How can this be done and is it possible at all? Maybe someone faced this? I would be grateful for advice because I rummaged through Google, but did not find anything for vp.

Answer 1

html5.by/blog/flexbox