React Js Convert Positive Number to Negative

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8" />
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState } = React;
    function App() {
      const [positiveNumber, setPositiveNumber] = useState(42);
      const [negativeNumber, setNegativeNumber] = useState();

.positive-number {
      font-size: 24px;
      color: #007bff;
      /* Blue color for positive numbers */
    }

.negative-number {
      font-size: 24px;
      color: #dc3545;
      /* Red color for negative numbers */
    }

.convert-button {
      margin-top: 20px;
      padding: 10px 20px;
      font-size: 18px;
      background-color: #28a745;
      /* Green color for the button */
      color: #fff;
      /* White text color */
      border: none;
      border-radius: 5px;
      cursor: pointer;
      transition: background-color 0.3s ease;
    }

.convert-button:hover {
      background-color: #218838;
      /* Darker green color on hover */
    }
  </style>
</body>

</html>