body {
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background-color: #70c5ce;
  font-family: Arial, sans-serif;
}

#game-container {
  position: relative;
  width: 100%;
  max-width: 400px;
  height: 600px;
  border: 2px solid #000;
  background: linear-gradient(to bottom, #70c5ce, #fff);
}

#gameCanvas {
  display: block;
  width: 100%;
  height: 100%;
}

#startButton {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: #ff6b6b;
  color: #fff;
  padding: 10px 20px;
  border-radius: 5px;
  font-size: 18px;
  cursor: pointer;
  display: none;
}