React Js Change color depending on Date Difference

<!DOCTYPE html>
<html>

</head>

<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState, useEffect } = React;

function App() {
      const targetDateStr = '2025-08-26'; // Replace with your target date
      const currentDate = new Date();
      const targetDate = new Date(targetDateStr);

// Validation: Check if 'targetDate' is a valid date and in the future.
      if (isNaN(targetDate.getTime()) || !/^\d{4}-\d{2}-\d{2}$/.test(targetDateStr) || targetDate <= currentDate) {
        return (
          <div className='container'>
            Invalid target date. Please provide a valid future date in YYYY-MM-DD format.
          </div>
        );
      }

const daysDifference = Math.ceil((targetDate - currentDate) / (1000 * 3600 * 24));

let color = 'black';

if (daysDifference <= 7) {
        color = 'orange'; // Within a week, change to orange
      } else {
        color = 'green';
      }

return (
        <div className='container'>
          <h3>React Js Change color depending on Date Difference</h3>
          Date Difference: <span style={{ color }}>{daysDifference} days</span>
        </div>
      );
    }

ReactDOM.render(<App />, document.getElementById('app'));
  </script>
  <style>
    /* Container */
    .container {
      font-family: Arial, sans-serif;
      max-width: 800px;
      margin: 0 auto;
      padding: 20px;
      border-radius: 8px;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
      text-align: center;
    }
  </style>
</body>

</html>