html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #050505;
  font-family: Arial, Helvetica, sans-serif;
  touch-action: none;
  overscroll-behavior: none;
  -webkit-user-select: none;
  user-select: none;
}

body {
  position: fixed;
  inset: 0;
}

canvas {
  display: block;
  margin: 0 auto;
  background: #000;
  touch-action: none;
  -webkit-tap-highlight-color: transparent;
}

#fullscreenButton {
  position: fixed;
  z-index: 20;
  right: max(14px, env(safe-area-inset-right));
  bottom: max(16px, env(safe-area-inset-bottom));
  min-width: 176px;
  min-height: 46px;
  padding: 10px 14px;
  border: 2px solid rgba(255, 255, 255, 0.68);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.72);
  color: #fff;
  font: bold 15px Arial, Helvetica, sans-serif;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  box-shadow: 0 4px 22px rgba(0, 0, 0, 0.48);
}

#fullscreenButton:active {
  background: rgba(130, 0, 0, 0.82);
  transform: translateY(1px);
}

#rotateHint {
  position: fixed;
  z-index: 19;
  left: 50%;
  top: max(18px, env(safe-area-inset-top));
  transform: translateX(-50%);
  display: none;
  padding: 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.45);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.68);
  color: rgba(255, 255, 255, 0.86);
  font: bold 14px Arial, Helvetica, sans-serif;
  letter-spacing: 0.03em;
  text-align: center;
  pointer-events: none;
}

body.is-fullscreen #fullscreenButton {
  display: none !important;
}