anchor.diff:  
   <style type="text/css">
   
  + 	
    	#open_video {
    		cursor: pointer;
    		margin-left: 1em;
  
positive.code:  		transition: all 300ms cubic-bezier(0.4, 0, 0.2, 1);
   	}
  
   	.video_block_accordion iframe {
  		max-width: 100%;
      height: 25em;
   	}
  
   	.video_block_accordion.closed {
   		opacity: 0;
   		transition: all 300ms cubic-bezier(0.4, 0, 0.2, 1);
   	}
  
   	#video_block {
   		display: none;
  
   	}
  
  
  
negative.code: 		    	<p class="p_block align_center"><%=t('contest_page.video_vote')%><span class="fa fa-chevron-down" id="open_video"></span></p>
  		    </div>
  
  				<div id="video_block">
  			    <div class="content_block">
  			    		<div class="video_block">
  					      <iframe class="video_presentation" width="480" height="250" src="https://www.youtube.com/embed/4J5TJsINiTc" frameborder="0" allowfullscreen></iframe>
  					     </div>
  					</div>
  				</div>
  				</br>
  			<% end %>
  