.interaction-hint {
  position: fixed;
  left: 50%;
  bottom: 10%;
  transform: translateX(-50%);
  padding: 10px 16px;
  background: rgba(0, 0, 0, 0.7);
  border: 1px solid var(--color-border);
  color: #eee;
  font-family: monospace;
  font-size: 14px;
  letter-spacing: 0.04em;
  z-index: var(--z-hint);
  pointer-events: none;
}

.interaction-hint-key {
  display: inline-block;
  margin-right: 8px;
  padding: 1px 8px;
  background: var(--color-accent-fill);
  border: 1px solid var(--color-accent-border);
  color: #fff;
  font-weight: 600;
}