text: ( function() {
  
  	var youtube = document.querySelectorAll( ".youtube" );
  	
  	for (var i = 0; i < youtube.length; i++) {
          
          // Unknown why some thumbnails acquired from Youtube with suffix sddefault.jpg is unavailable
  		var source = "https://img.youtube.com/vi/"+ youtube[i].dataset.embed +"/0.jpg";
  		
  		var image = new Image();
  				image.src = source;
  				image.addEventListener( "load", function() {
  					youtube[ i ].appendChild( image );
  				}( i ) );
  		
  				youtube[i].addEventListener( "click", function() {
  
  					var iframe = document.createElement( "iframe" );
  
  							iframe.setAttribute( "frameborder", "0" );
  							iframe.setAttribute( "allowfullscreen", "" );
  							iframe.setAttribute( "src", "https://www.youtube.com/embed/"+ this.dataset.embed +"?rel=0&showinfo=0&autoplay=1" );
  
  							this.innerHTML = "";
  							this.appendChild( iframe );
  				} );	
  	};
  	
  } )();
  
  // Attach this to html
  // <!-- (1) video wrapper -->
  // <div class="youtube" data-embed="rcPLKO-TGfQ">
  //     <!-- (2) the "play" button -->
  //     <div class="play-button"></div> 
  // </div>