/* ── Card stacks (#7) ── */
.memory-card.is-stacked {
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms ease;
}

.stack-badge {
  position: absolute;
  top: 6px;
  right: 6px;
  background: var(--marker);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 800;
  border-radius: 10px;
  padding: 2px 8px;
  z-index: 10;
  cursor: pointer;
  pointer-events: all;
  transition: transform 150ms ease;
}
.stack-badge:hover {
  transform: scale(1.15);
  background: #17596f;
}