html, body {
  margin: 0;
  padding: 0;
}
canvas {
  display: block;
}

.arrow {
  font-family: Arial, Helvetica, sans-serif;
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1em;
  color: #1a53ff;
  cursor: pointer;
  z-index: 1000;
  padding: 10px 20px;
  transition: background 0.2s ease;
}

.arrow:hover {
  color: #1a53ff49;
}

.arrow.right {
  right: 20px;
}