7.1 Possible to limit vertical height of all Lightbox images?

Question for Squarespace 7.1 template ( I'm using the Elliott template ) 

I'm building a Site ( can't show the example site yet ).   But I have a general question.

is there a general code i can add to CSS to limit the height of ALL images in a lightbox when you magnify them? 

I understand squarespace adapts image sizes to the screen/ window size but I feel like all my images are tooo big on 4k montiors... 

For example.   I like how the website looks on a 1920x1080 screen resolution. However on a 4k monitor with the browser window maximized the  magnified lightbox images are too big.  I'd like to add a max image height / size on all lightbox images on my site. 

thoughts?