* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100svh;
  overflow: hidden;
}

#wrapper {
  position: relative;
  width: min(100vw, 480px);
}

canvas {
  display: block;
  width: 100%;
  aspect-ratio: 480 / 760;
  cursor: none;
  touch-action: none;
}

.flipper-btn {
  position: absolute;
  bottom: 0;
  width: 44%;
  height: 64px;
  background: rgba(0, 255, 255, 0.06);
  border: 1px solid rgba(0, 255, 255, 0.25);
  border-bottom: none;
  color: rgba(0, 255, 255, 0.45);
  font-size: 1.8rem;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  cursor: pointer;
}

#btn-left  { left: 0;  border-left: none;  border-radius: 0 8px 0 0; }
#btn-right { right: 0; border-right: none; border-radius: 8px 0 0 0; }

/* Hide on desktop (fine pointer / mouse) */
@media (hover: hover) and (pointer: fine) {
  .flipper-btn { display: none; }
}