text: $( document ).ready(function()
  {
    var sup = $('sup');
    sup.addClass('popup');
  
    sup.on('click', function(self){popupToggle(this);});
    $('sup span').addClass('popup-text');
  });
  
  function popupToggle(self)
  {
    var sup = $(self).children('.popup-text').toggleClass('show');
  }
  