* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #000;
}
#view {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  touch-action: none;
}
#start {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #000;
  z-index: 10;
}
#start.hidden {
  display: none;
}
#startButton {
  font-size: 1.5rem;
  padding: 1em 2em;
  border-radius: 0.5em;
  border: 1px solid #fff;
  background: #111;
  color: #fff;
}
#controls {
  position: fixed;
  bottom: env(safe-area-inset-bottom, 0);
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  gap: 1em;
  padding: 1em;
  z-index: 5;
}
#controls button {
  font-size: 1.2rem;
  padding: 0.6em 1em;
  border-radius: 0.5em;
  border: 1px solid rgba(255,255,255,0.4);
  background: rgba(0,0,0,0.4);
  color: #fff;
}