“minimal-ui” mode hides the bottom navigation and shrinks the address bar of mobile Safari. To enable it, add minimal-ui to the viewport meta tag.
Safaris button navigation will only be visible, when the user taps the address bar. This is especially important if a website has a navigation at the bottom of the page, as one would have to tap twice without minimal-ui to activate a link.
<meta name="viewport" content="minimal-ui">
<meta name="viewport" content="width=device-width,minimal-ui">
example 2 is applied on this site.
tip by @max_hoffmann