Responsive gallery for images of different widths?

Question

css

I saw an adaptive gallery on this site. ( www.lofterud.se/architecture )
Perhaps some of you know how to implement the same.

It just fills up perfectly. The height and width of images, regardless of screen size, always adjusts as needed.
The main task is to give the browser the fit of all photos, so that he himself selects the height and width for the elements.
If someone gives an answer or direction, I will be very grateful to you)))

Answer 1

I didn’t see an adaptive gallery there ... I
probably have a special computer and a Samsung and some kind of left iPhone