body {
  margin: 0;
  font-family: Arial;
  background: black;
  color: white;
  text-align: center;
}

.hidden {
  display: none;
}

button {
  padding: 15px;
  margin: 10px;
  font-size: 18px;
}

canvas {
  display: none;
}

#jumpBtn {
  position: fixed;
  bottom: 20px;
  right: 20px;
  padding: 25px;
  font-size: 20px;
  background: orange;
}