.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 58px;
  height: 58px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 3px solid var(--black, #222222);
  background: var(--yellow, #fcb900);
  color: var(--black, #222222);
  box-shadow: 5px 5px 0px var(--black, #222222);
  cursor: pointer;
  z-index: 250;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 0.2s ease, transform 0.2s ease, box-shadow 0.15s ease;
}

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

.back-to-top:hover {
  transform: translate(-1px, -1px);
  box-shadow: 7px 7px 0px var(--black, #222222);
}

.back-to-top:active {
  transform: translate(2px, 2px);
  box-shadow: 3px 3px 0px var(--black, #222222);
}

.back-to-top svg {
  width: 22px;
  height: 22px;
}

@media (max-width: 768px) {
  .back-to-top {
    right: 16px;
    bottom: 16px;
    width: 52px;
    height: 52px;
    box-shadow: 4px 4px 0px var(--black, #222222);
  }
}