Why is positioning not displayed correctly?

Question

Sass

Hello, I ran into a problem, positioning is displayed differently, if you view through a tab that is updated by browser-sync, everything is in place, but if you open the index file directly from the folder, everything moves out. I don’t post the code, maybe it’s a large canvas, but if the problem is not of a general nature and it will be necessary to look at the code, I’ll attach it.