Can you advise a better way to display a popover of catalog items?

I have a catalog that I need to show full on one page. The catalog contains categories, subcategories, and items (5-12 items inside a subcategory). That's what it looks like (please, see the attached picture).

The new challenge is to show a preview of items (picture, title, brief) when a user puts the mouse cursor on a link (please, see the right side of the attached picture).

What do you think there's any better way to show the preview of items? For now, it overlaps much of the rest content (other items of the catalog) when opening.

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and/or maybe you know the way how to completely reorganize the current catalog to a better experience.

Thanks!