How to Set Up Source Engine-Style Inventory Scroll?

I thought I did, but apparently not. Anyway, that did it! My inventory finally scrolls and highlights like I want! It’s a beautiful sight to behold. LOL

I can’t thank you enough for how patient and informative you’ve been. I sincerely appreciate your help.

Edit: Well, one last question. How to do the opposite scroll direction? I’m trying to figure that one out myself, but not having any luck.