text: 'use strict';
  
  window.addEventListener('DOMContentLoaded', function() {
  
    var iframeContainer = document.querySelector('#iframe-container'),
        iframeCover = document.querySelector('#iframe-cover'),
        iframe = document.querySelector('iframe');
  
    iframeCover.onclick = function() {
      iframeContainer.style.display = 'none';
      iframeCover.style.display = 'none';
      iframe.src = 'about:blank';
    }
    
    iframe.onclick = function(e) {
      e.stopPropagation();
      e.preventDefault();
    }
  
    var iframe = document.querySelector('iframe'),
        links = document.querySelectorAll('a');
  
    for (var i = 0; i < links.length; i++) {
      links[i].onclick = function() {
        iframeCover.style.display = 'block';
        iframeContainer.style.display = 'block';
        iframe.src = this.dataset.url;
      }
    }
  
  });
  