JSFiddle - React, Tailwind, and code Playground

HTML

<div class="navigation">
<p>Navigation</p>
</div>
<hr style="width: 30%;"></hr><br />

<div class="balken">
<br />
<div id="content">


<div class="forum">
<img src="https://www.gravatar.com/avatar/90edc3b12944d0017b29a998fd6a4766/?default=&s=64" style="margin-right: 110px;"  />
</div>

</div>
<br />
</div>

<p class="fgeheim">Test</p>

CSS

.fgeheim {
 opacity:0;
 color: black;
}
.forum:hover img > .fgeheim {
opacity:100;
}