#csi-scroll-top {
  position: fixed;
  right: max(18px, env(safe-area-inset-right));
  bottom: max(24px, env(safe-area-inset-bottom));
  z-index: 30;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid #4a4c64;
  border-radius: 6px;
  background: #1e1f33;
  color: #fff;
  cursor: pointer;
  box-shadow: 0 2px 8px #0003;
}
#csi-scroll-top[hidden] { display: none !important; }
#csi-scroll-top:hover { background: #34364e; }
#csi-scroll-top:focus-visible { outline: 3px solid #ffb000; outline-offset: 3px; }
@media (max-width: 639px) {
  #csi-scroll-top { bottom: calc(80px + env(safe-area-inset-bottom)); }
}