// Event listener switch for visible tab using Page Visibility
window.addEventListener('visibilitychange', () => {
  switch(document.visibilityState) {
    case 'prerender':
      console.log('Tab is pre-rendering');
      break;
    case 'hidden':
      console.log('Tab is hidden');
      break;
    case 'visible':
      console.log('Tab is focused');
      break;
  }
};