.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 84px;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--blue);
  border-radius: 999px;
  background: var(--blue-weak);
  color: var(--blue);
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
  z-index: 60;
}

.back-to-top:hover {
  background: var(--blue);
  color: #fff;
}

.back-to-top:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top__arrow {
  font-size: 18px;
  line-height: 1;
  font-weight: 700;
}

@media (max-width: 840px) {
  .back-to-top {
    right: 14px;
    bottom: 88px;
  }
}