Button that leads to the previous slide situated very closely to the expand/collapse block

[NothingEverHappens]

What the issue is about

Button that leads to the previous slide situated very closely to the expand/collapse block of code button in the code editor" on page https://codelab.fun//angular/forms/forms-validation-2

https://screenshot.googleplex.com/CQ2jTLZjGPJ

What would be a good fix?

This issue requires some UX analysis.
It's not limited to this page and will affect every other slide, so we need some good UX ideas here.

Where to start

Suggest a way to resolve it in this issue here in the comments