.scroll-to-top-btn {
  position: fixed;
  right: 24px;
  bottom: 32px;
  width: 48px;
  height: 48px;
  border: none;
  border-radius: 50%;
  background: var(--color-background-base, #fff);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: opacity 0.3s, visibility 0.3s, background 0.2s;
  opacity: 0;
  visibility: hidden;
  z-index: 10000;
}

.scroll-to-top-btn.show {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top-btn:hover {
  background: var(--color-background-hover, #f5f5f5);
}