Page Preview on Hover widget or code?

Hi Squarespace Forum,

I'm currently working on a website and wondered if it's possible to have a button/image that, when hovered over, would show a preview in a Lightbox of sorts of the page, which would go through to it when clicked? I'm open to whether this would be a widget or coding.

Alternatively, is there a way to get a page to slide out on a sidebar? So not entirely taking the user to a new page, but instead open a sidebar that can be closed?

Thanks,

Thomas