Customize public link preview landing page template / theme?

Where do I go again to customize the preview link landing page? What I’d really like to do, is “center align” the content and default collapse “Discuss this file Join conversation” talk sidebar trigger panel. I do not see an option in the talk app settings page either (

So for example, if I “copy public link” and visit that link in a private tab, where do I customize that landing page?


p.s. - You know what else I noticed by the way? If I “share a folder” and that folder has videos. I click a video and the link preview starts a slideshow. It’s beautiful. Has the dark background colored modal and everything is centered. I think it’s only available for sharing folders though…