Why does the "fancy-box" library take the height of the entire site?

Question

css

Connected the library.
The scripts all work. All right.
I click on the picture, and a huge modal pops up to the entire height of the site at the very top of the controls and somewhere in the middle the picture that should be displayed.
Faced the problem for the first time.
Perhaps CSS is recycled?

How can I fix this to 100% screen height..
Thank you.

Answer 1

If anyone will be useful. Found a "bug" if I may say so.
There was a property in the css-styles transform: translate3d(0, 0, 0);so that the site would not flicker from various kinds of animation. And he was with all the elements. It turns out that it somehow interrupts the property transformof the library itself. That's it.