Fixed Split Section

I've been trying to do a fixed split section setup. So I want the first section to be split around 30% but fixed with a full height.  Then,  I want the second section to be 70% scrolling. I tried multiple times but the second section doesn't wrap. It wouldn't work in FE so I am using 7.1 sections.

Here's an example of what I am shooting for: https://www.shawnbinder.com/

W: https://llama-clementine-787h.squarespace.com/

p:demo

I did figure it out but thanks for the info.