JSFiddle - React, Tailwind, and code Playground
HTML
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
<div class=slide>Not now</div>
<div class=slide><div class=informations>Now</div></div>
<div id="logo">
XXX
</div>
CSS
.slide {
width: 100vw;
height:100vh;
line-height:100vh;
}
#logo {color:black; position:fixed; top:10px; left:10px}
.informations {background:black}
.white {color:white;}
JavaScript
$(document).ready(function(){
if ($('.informations').is(':visible')){
$('#logo').addClass("black");
}
});