https://ederdiaz.dev/blog/how-i-made-a-fluid-layout-component-wot-w/
This post explains how can you achieve creating a two column layout that changes it's width when a button is pressed.
i madefluid layoutcomponentwotw
https://slidea.pixevil.com/documentation/layouts/fluid.html
Slidea by Pixevil is a super smart, fast, responsive and modular multi-purpose content slider which completely leaves the competition behind.
fluid layoutdocumentation
https://www.wpbeginner.com/glossary/fluid-layout/
Definition of fluid layout in WordPress. What are fluid layout themes in WordPress and how to make a WordPress theme layout fluid.
what isfluid layoutwordpress