body {
  margin: 0;
  overflow: hidden;
  background: #111;
  font-family: sans-serif;
}
canvas {
  display: block;
}
#instructions {
  position: absolute;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  color: #fff;
  background: #000;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  pointer-events: none;
  z-index: 10;
}
#sensor-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: #000;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 9999;
}
#sensor-overlay h1 {
  color: #fff;
  text-align: center;
  margin-bottom: 30px;
  font-family: sans-serif;
}
#unlock-btn {
  padding: 15px 40px;
  font-size: 18px;
  font-weight: bold;
  background: #00ffff;
  color: #000;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.2s;
}
#unlock-btn:active {
  transform: scale(0.95);
}