How to fix scroll to the top of the page when opening a modal window?

Question

css

Good day to all. I need your help. The problem usually manifests itself on the screens of mobile devices. When you click on the gallery, for example, a scroll to the top of the page is noticeable, after closing the gallery, we do not return to the place of the click, but remain at the very top of the page. The site itself (I do not argue that it is a masterpiece))) can be viewed here f0151394.xsph.ru