body {
  font-family: Arial, sans-serif;
  text-align: center;
  background-color: #f0f0f0;
}

#gameArea {
  width: 500px;
  height: 500px;
  margin: 20px auto;
  background-color: #fff;
  border: 2px solid #333;
  position: relative;
}

#square {
  width: 50px;
  height: 50px;
  background-color: red;
  position: absolute;
  cursor: pointer;
}