body {
      margin: 0;
      overflow: hidden;
      background: #121212;
      color: #fff;
      font-family: sans-serif;
      text-align: center;
    }
    #score, #timer {
      font-size: 30px;
      margin: 10px;
    }
    #box {
      width: 60px;
      height: 60px;
      background: #ff4040;
      position: absolute;
      border-radius: 50%;
      cursor: pointer;
      box-shadow: 0 0 20px #ff4040;
      display: none;
    }
    #gameover {
      font-size: 50px;
      color: #ffcc00;
      position: absolute;
      top: 40%;
      left: 50%;
      transform: translate(-50%, -50%);
      display: none;
    }
    #startBtn {
      padding: 15px 30px;
      font-size: 24px;
      background: #28a745;
      border: none;
      color: white;
      border-radius: 8px;
      margin-top: 30px;
      cursor: pointer;
    }