Stop video from playing after pop-up modal closes

Hi! I created a pop-up modal that opens on an embedded video element (Vimeo / OneLinePlayer) by clicking ‘Watch’ All looks good, but the video keeps playing after closing the pop-up.

How do I make sure the video stops playing after closing? I know there are quite some topics on this forum about this, but I’m quite a novice when it comes to coding and couldn’t make sense of it while trying to figure it out on my own website.

The read-only link doesn’t seem to display the website all that well, so here is the published version:

Thank you!

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