How to create the scroll effect on the squarespace Zendaya site where the video resizes upon scrolling.

Site URL: https://www.squarespace.com/zendaya

I contacted squarespace tech support to see what features were used to create the scroll functionality on their site https://www.squarespace.com/zendaya. 

They said it was custom code to make the video shrink upon scrolling and have the text move in from the sides. 
Anyone have any tips or code for how this is done?
 

On 2/15/2022 at 1:09 AM, paul2009 said:

For example, the video shrinking script uses a transform to scale the hero video element in response to changes in the scrollY property of the Window interface as you scroll down. It also adds an increasing border radius on the corners to round off the edges. 

I saw this "effect" on another website too.

1.  Are there any third party "plug-ins" or bits of code "pre-written" to achieve this? 

2. Is this effect possible in 7.1?