body {
      text-align: center;
      padding-top: 60px;
      background-color: #f8f9fa;
    }
    #box {
      width: 300px;
      height: 150px;
      margin: 30px auto;
      background-color: #6c757d;
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.4rem;
      border-radius: 8px;
      cursor: pointer;
      user-select: none;
    }