.game-area {
  padding: 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}

.stack {
  position: relative;
  width: 100%;
  max-width: 340px;
  aspect-ratio: 320 / 140;
  background: #eee;
  border: 1px solid #ccc;
  border-radius: 8px;
}

.stack svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

#calque-b-svg { touch-action: none; cursor: grab; }
#calque-b-svg:active { cursor: grabbing; }

.frag-a { fill: #222; opacity: 0.85; }
.frag-b { fill: #222; opacity: 0.85; }

.corner-mark { font-size: 10px; fill: #999; }
.grid-tick { stroke: #ccc; stroke-width: 1; }

.b-controls {
  display: flex;
  gap: 8px;
  width: 100%;
  max-width: 340px;
}
.b-controls button { flex: 1; }