html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: #6ec6ff;
  overflow: hidden;
}

canvas {
  display: block;
  image-rendering: auto;
}

.controls {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 18px;
  z-index: 9999;
}

.leftGroup, .rightGroup {
  display: flex;
  gap: 12px;
}

.btn {
  width: 74px;
  height: 74px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.35);
  font-size: 26px;
  color: #0b1220;
  background: rgba(255,255,255,0.8);
  box-shadow: 0 8px 20px rgba(0,0,0,0.25);
  user-select: none;
  touch-action: none;
}

.btn:active {
  transform: scale(0.95);
}