#btnTop {
  display: none;
  position: fixed;
  right: 2rem;
  bottom: 5.5rem;
  width: 4.2rem;
  height: 4.2rem;
  background: rgba(249, 249, 249, 1);
  box-sizing: border-box;
  z-index: 1000;
  border-radius: 0.5rem;
  border: none;
  margin-bottom: env(safe-area-inset-bottom, 0);
}

#btnTop.higher {
  bottom: 11rem;
}

#btnTop:after {
  top: 50%;
  left: 50%;
  width: 1.5rem;
  height: 0.9rem;
  margin: -0.45rem 0 0 -0.75rem;
  background-position: 100% -2.7rem
}


@media screen and (min-width:550px) {
  #btnTop { right:auto !important; left:50%; margin-left:170px; }
}