running environment: mobile safari browser.

usually I implement the navigation bar fixed at the top using position:fixed. Although it is fixed at the top, this writing will be obscured by the rubber band effect when the page is pulled down in safari.
the navigation bar of Apple"s official website can be fixed when scrolling, and the entire page can follow the rubber band effect when you drop down, and the navigation bar is in the entire visual area.

you can"t listen to the scroll bar position to add fixed later.

question 1: how to fix the navigation bar of Apple"s official website on mobile
or question 2: how to disable the rubber band effect.