Untitled

<!DOCTYPE html>
<html>
<head>
  <title>Fullscreen on Click or Key Press</title>
</head>
<body>
  <p>Click anywhere or press any key to enter fullscreen mode -_- .</p>

  <input type="text" id="user-input" placeholder="Type something here..." style="width: 300px; padding: 8px; font-size: 16px;">

  <script>
    function enterFullscreen() {
      if (!document.fullscreenElement) {
        document.documentElement.requestFullscreen().catch((err) => {
          console.error(`Error attempting to enable fullscreen mode: ${err.message} (${err.name})`);
        });
      }
    }

    // Trigger on first click
    document.addEventListener('click', enterFullscreen, { once: true });

    // Trigger on first key press
    document.addEventListener('keydown', enterFullscreen, { once: true });
  </script>
</body>
</html>