* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; }

body {
  background: #0d1522 radial-gradient(circle at 50% 18%, #182a44 0%, #0d1522 72%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  font-family: system-ui, "Microsoft YaHei", "PingFang SC", sans-serif;
  -webkit-user-select: none;
  user-select: none;
}

canvas {
  display: block;
  touch-action: none;
  -webkit-tap-highlight-color: transparent;
  border-radius: 14px;
  box-shadow: 0 12px 60px rgba(0, 0, 0, 0.55);
}

#muteBtn {
  position: fixed;
  top: 12px;
  right: 12px;
  width: 44px;
  height: 44px;
  font-size: 20px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  cursor: pointer;
  z-index: 10;
  backdrop-filter: blur(4px);
  transition: background 0.15s;
}
#muteBtn:hover { background: rgba(255, 255, 255, 0.2); }