How can I get video links to pop up?

I tried searching for answers to this question and came up short but if anyone can link me I'd be greatly appreciative

I'm wondering how to create a sort of 'pop up video' on my site. You click on a link, and instead of directing you to a different website or playing the video within the confines of the thumbnail space it will have a whole screen pop up which envelops a majority of the size of the web browser. I attached an example. I've seen this on a bunch of sites I just can't find where/how to do this on squarespace....

it occured to me that a 'pop up' style video may not be the right terminology here... what i'm looking for is more like a window within a window--you click on the video link and it doesn't redirect you to a new page or open a new one, it sort of creates a bubble that fills the window you are already in

UPDATE: I'm still not 100% there, but I discoverd an important thing about this question which is that what I'm looking for is called a 'lightbox' so for any wandering people looking for an answer to the same question, that's what it's called

There's a tutorial here, but apparently it's only for v7.0 squarespace and it does not apply to the newest version which is v7.1

Lightbox, of course--not to be confused with this scene from space odyssey, but perhaps I am just as perplexed