body{
  margin: 0;
  margin-top: 4rem;
  padding: 0;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: darkgray;
}

#gameCanvas {
  background-image: url("image/star.gif");
  background-size: cover;
  border: 2px solid white;
}

#startScreen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 999;
}

#startButton {
  padding: 10px 20px;
  background-color: #fff;
  color: #000;
  font-size: 24px;
  cursor: pointer;
}

#gameOverScreen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 999;
  display: none;
}

#restartButton {
  padding: 10px 20px;
  background-color: #fff;
  color: #000;
  font-size: 24px;
  cursor: pointer;
}