/* Urgent navigation invariant: preserve native v8.2 bottom bar geometry. */
#nav{
  position:fixed!important;
  left:50%!important;
  right:auto!important;
  top:auto!important;
  bottom:calc(10px + env(safe-area-inset-bottom))!important;
  width:calc(100% - 24px)!important;
  max-width:600px!important;
  transform:translateX(-50%)!important;
  z-index:10!important;
}