/* Fixed bottom-right control stack: the background-reveal toggle and the
   effects drawer share one flex column so added buttons stack instead of
   overlapping. column-reverse keeps the first DOM child pinned to the
   viewport corner as later items stack upward from it. */
.site-controls {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 4;
  display: flex;
  flex-direction: column-reverse;
  align-items: flex-end;
  gap: 0.75rem;
}

.bg-reveal-toggle,
.fx-panel-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg-elevated);
  color: var(--text);
  cursor: pointer;
  transition:
    background-color 180ms ease,
    border-color 180ms ease,
    color 180ms ease;
}
.bg-reveal-toggle[aria-pressed="true"],
.fx-panel-toggle[aria-expanded="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg-elevated);
}
.control-icon {
  width: 1.15rem;
  height: 1.15rem;
  display: block;
  fill: currentColor;
}
.control-icon[fill="none"] {
  fill: none;
  stroke: currentColor;
}

/* Drawer for per-effect buttons (pause petals, pause dust, ...). Collapsed
   by default so a handful of optional effects never crowd the corner;
   opening it slides the list up from behind its toggle. */
.fx-panel {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.5rem;
}
.fx-panel__list {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.5rem;
  opacity: 0;
  transform: translateY(0.5rem);
  pointer-events: none;
  transition:
    opacity 180ms ease,
    transform 180ms ease;
}
.fx-panel__list.is-open {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
/* Feature buttons style themselves for standalone use (fixed, corner-
   anchored); neutralize that positioning once nested in the drawer. */
.fx-panel__list > button {
  position: static;
}