.scroll-top-button {
  position: fixed;
  right: max(18px, env(safe-area-inset-right));
  bottom: max(18px, env(safe-area-inset-bottom));
  z-index: 9999;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 50%;
  background: rgba(15, 17, 20, 0.58);
  color: #fff;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
  cursor: pointer;
}
.scroll-top-button.is-visible {
  opacity: 0.78;
  visibility: visible;
  transform: translateY(0);
}
.scroll-top-button:hover,
.scroll-top-button:focus-visible {
  opacity: 1;
  outline: 2px solid #fff;
  outline-offset: 2px;
}
.scroll-top-button span {
  font-size: 27px;
  font-weight: 500;
  line-height: 1;
  transform: translateY(-1px);
}
@media (max-width: 600px) {
  .scroll-top-button {
    width: 44px;
    height: 44px;
  }
}