<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Digital Clock with Selectable Fonts</title>
  <style>
    body {
      font-family: Arial, sans-serif;
      text-align: center;
      padding-top: 50px;
      background-color: #f0f0f0;
    }
    #clock {
      font-size: 4em;
      margin: 20px;
      padding: 10px;
      background: #fff;
      display: inline-block;
      border-radius: 8px;
      box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    }
    #controls {
      margin-bottom: 20px;
    }
    label {
      font-size: 1.2em;
      margin-right: 10px;
    }
  </style>
</head>
<body>
  <div id="controls">
    <label for="fontSelector">Select Font:</label>
    <select id="fontSelector">
      <option value="Arial" selected>Arial</option>
      <option value="Courier New">Courier New</option>
      <option value="Georgia">Georgia</option>
      <option value="Times New Roman">Times New Roman</option>
      <option value="Verdana">Verdana</option>
    </select>
  </div>
  <div id="clock">00:00:00</div>

  <script>
    // Function to update the clock display
    function updateClock() {
      const now = new Date();
      let hours = now.getHours();
      let minutes = now.getMinutes();
      let seconds = now.getSeconds();

      // Format time with leading zeros if needed
      hours = hours < 10 ? '0' + hours : hours;
      minutes = minutes < 10 ? '0' + minutes : minutes;
      seconds = seconds < 10 ? '0' + seconds : seconds;

      const timeString = hours + ':' + minutes + ':' + seconds;
      document.getElementById('clock').textContent = timeString;
    }

    // Update the clock every second
    setInterval(updateClock, 1000);
    updateClock(); // initial call so the clock isn't empty on load

    // Change the clock's font when the user selects a different font
    document.getElementById('fontSelector').addEventListener('change', function() {
      const selectedFont = this.value;
      document.getElementById('clock').style.fontFamily = selectedFont;
    });
  </script>
</body>
</html>