.back-to-top {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  z-index: 40;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0;
  border: 1px solid rgba(0, 0, 0, 0.15);
  border-radius: 999px;
  background: var(--color-primary, #dc143c);
  color: #ffffff;
  font: inherit;
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(0.5rem);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

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

.back-to-top:hover,
.back-to-top:focus-visible {
  filter: brightness(1.08);
  outline: 2px solid var(--color-primary, #dc143c);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top {
    transition: none;
  }
}