Color sticky overlay

Hello guys.

My ideas are coming to end for building this layout. So im gonna need some help with positioning color overlay on this scroll div and it has to stick when scrolled. Thanks for any help!

My readonly link: Webflow - spix

Here is my site Read-Only: LINK
(how to share your site Read-Only link)


Is there a question here?

Yes, sorry if the question wasn’t clear.

So I need the color overlay scroll with the div. So if a user scrolls a gallery down and then hovers out of the scrollable area the dark overlay should appear.
Right now you can see the color overlay is positioned only to top

How can I get this kind of effect?