JSFiddle - React, Tailwind, and code Playground

HTML

<table>
<tr><td class="tribe-events-thismonth tribe-events-future tribe-events-has-events mobile-trigger tribe-event-day-31 tribe-events-right">
				
<!-- Day Header -->
<div id="tribe-events-daynum-31-1">

			<a href="http://fleetinsel.com/wp/kalender/2018-08-31/" aria-label="">
			31		</a>	</div>

<!-- Events List -->
	
<div id="tribe-events-event-74-2018-08-31" class="tribe-events-category- post-74 tribe_events type-tribe_events status-publish hentry tag-keyword-1 tribe-events-venue-62" >
	<h3 class="tribe-events-month-event-title"><a href="http://fleetinsel.com/wp/veranstaltung/showcase/" class="url">Showcase</a></h3>
</div><!-- #tribe-events-event-# -->




<!-- View More -->
			</td>
      </tr>
</table>

CSS

.tribe-events-has-events div {font-size:72px;}

.tribe-events-has-events div a {width:200px;height:200px;background: yellow; font-family:serif;}

.black-nr {font-family: sans-serif!important; background:none!important;}

.tribe_events.type-tribe_events {display:none;}

JavaScript

$('.tribe-events-has-events div').hasClass('cat_opening-de').children('a').addClass('black-nr');