/* ML Base feature: back to top */
.ml-back-to-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 50;
  width: 44px;
  height: 44px;
  border: 1px solid var(--ml-border);
  border-radius: var(--ml-button-radius);
  background: var(--ml-primary);
  color: #fff;
  cursor: pointer;
  box-shadow: var(--ml-shadow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity .18s ease, transform .18s ease;
}
.ml-back-to-top.is-visible { opacity: 1; pointer-events: auto; transform: translateY(0); }