Best way to replicate this site's CMS overlay

Hi, I love the portfolio overlay at https://www.citrona.studio/

I can do the CMS slider, but what is recommended for the best option for the overlay (best JS code to use, or any examples anyone knows of I can clone or view in read only mode).

I can use the Google API to do the video auto play…


Here is my public share link: LINK
(how to access public share link)