Set featured image size by screen width

Hi,

How can I set the width and height of featured images by viewport size? If I set a height of 400px in the Customizer the image becomes to large on mobile. I'd like the featured image to be aesthetically correct on desktop, tablet, on mobile, and always be the same height dependent on viewport. So 400px looks right on desktop, where as 200-230px looks right on mobile. But the Customizer height setting is global.

I saw this thread but couldn't see the answer in there:
https://generatepress.com/forums/topic/how-to-put-a-small-size-featured-image-on-mobile-posts-and-pages/#post-1826124

Thanks for your help,
Paul.