How to have UI elements be the same size across different containers?

How can I have all the slots be the same?
They’re all inside different containers but I want the slot sizes to remain the same desite the size difference. Right now I’m using scale instead of offset. The problem with offset is that it makes the slots clumped together or just really small depending on the screen but they at least have the same slot size.

I’m going to script this so that you can drag slots from one place to another so it’s pretty imperative that they are all the same size.

I’m also a scripter, not a UI designer. My boss just told me to put this together. Sorry if I’m not familiar with UI basics.

Hotbar uses UIListLayout, Inventory uses UIGridLayout (absolute size), Right side uses individually scaled & placed.

Because scale takes 100% of their parent when set to 1 and offset takes 100px when set to 100