body {
  margin: 0;
  background: #f7f7f7;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  font-family: 'Open Sans', sans-serif;
  overflow: hidden;
}

#game {
  background: #fff;
  border: 1px solid #ccc;
  border-radius: 8px;
  image-rendering: pixelated;
}

#overlay {
  position: relative;
  width: 900px;
  text-align: center;
}

#game-over {
  position: absolute;
  top: 120px;
  left: 0;
  right: 0;
  display: none;
}

#game-over.show {
  display: block;
}

#game-over h2 {
  font-size: 28px;
  color: #222;
  margin: 0 0 10px;
}

#restart {
  padding: 10px 16px;
  font-weight: 600;
  background: #222;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

#footer {
  color: #888;
  font-size: 13px;
  margin-top: 10px;
}