Hi there, thank for all your help.
May I ask for one more thing?
FIXXED THIS: So - my top nav-bar is set as a sticky bar without shrink, so it does not make that strange jitter.
But now the problem is that, the section unter the sticky bar, which in my case it the bar showing the page title and breadcrumbs, hides completely as soon as the bar goes under the nav bar. So again it does not look smooth. I played with different settings, but till now I couldn’t fix the problem.
FIXXED: OK, I found a solution for the problem above. I set my navigation-bar to absolute, sticky-bar, shrink 0.7, keep margin and z-index stack (<- maybe not necessary?) and added a bar with the same height under it and set this one to relative.
Now the scrolling works fine, without any jitter or jumping around.
One minor thing. I added shadow to the nav-bar also, but I don’t want it to cast the shadow to the white bar with the page title and breadcrumb. Is there a way to avoid this? But I do like to have the shadow when scrolling through the site to separate the navigation bar from the page content.
EDIT 2: Oh, seems that today is good day. I was able to fix also my second problem. Don’t know if my solution is a bit chaotic, but it works. I added a third transparent bar just for the shadow with the proper z-index.
If you like, you can check it out. Thanks. 