I like the well done hiding nav bar in my browser but the web ones tend to go mental popping up and down randomly. And then it just magnifies the crappiness whe

I like the well done hiding nav bar in my browser but the web ones tend to go mental popping up and down randomly. And then it just magnifies the crappiness when you have 2 stacked nav bars from the browser and website which are both trying to hide/unhide. The ideal hiding navbar is one which is the only one on the screen and one which only pops down as much as the user scrolls so you have to scroll up one navbars worth to get the full thing and not the ones where you scroll up 1 px by accident and the full navbar flys down