React Js Calculate Seconds Difference Between Two Dates

<!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;
    const App = () => {
      const [date1, setDate1] = useState('');
      const [date2, setDate2] = useState('');
      const [secondsDifference, setSecondsDifference] = useState(null);

const calculateDifference = () => {
        const startDate = new Date(date1);
        const endDate = new Date(date2);

if (!isNaN(startDate) && !isNaN(endDate)) {
          const differenceMilliseconds = endDate - startDate;
          const seconds = Math.abs(differenceMilliseconds / 1000);
          setSecondsDifference(seconds);
        } else {
          alert('Invalid date format. Please use YYYY-MM-DDTHH:mm.');
        }
      };

return (
        <div className='container'>
          <h2>React Js Calculate Seconds Difference Between Two Dates</h2>
          <div>
            <label>Date 1:</label>
            <input type="datetime-local" value={date1} onChange={(e) => setDate1(e.target.value)} />
          </div>
          <div>
            <label>Date 2:</label>
            <input type="datetime-local" value={date2} onChange={(e) => setDate2(e.target.value)} />
          </div>
          <button onClick={calculateDifference}>Calculate Difference</button>
          {secondsDifference !== null && (
            <div>
              <p>Seconds Difference: {secondsDifference} seconds</p>
            </div>
          )}
        </div>
      );
    }

ReactDOM.render(<App />, document.getElementById('app'));
  </script>
  <style>
    .container {
      border-radius: 8px;
      box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.1);
      padding: 20px;
      margin: 20px auto;
      max-width: 400px;
      text-align: center;
    }

h2 {
      font-size: 24px;
      margin-bottom: 20px;
    }

label {
      font-weight: bold;
      margin-bottom: 10px;
      display: block;
    }

input[type="datetime-local"] {
      width: 100%;
      padding: 10px;
      margin-bottom: 20px;
      border: 1px solid #ccc;
      border-radius: 4px;
    }

button {
      background-color: #007bff;
      color: #fff;
      padding: 10px 20px;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 16px;
      transition: background-color 0.3s ease;
    }

button:hover {
      background-color: #0056b3;
    }

div>p {
      font-size: 20px;
      margin-top: 20px;
    }
  </style>
</body>

</html>