JSFiddle - React, Tailwind, and code Playground

HTML

<span class="texte">leTexte</span>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.0/jquery.min.js"></script>

CSS

.texte{
  fontSize:100px;
}

JavaScript

var taille = 100;
$(".texte").css("fontSize", "100px");

$(".texte").click(function(){

	 taille  = 300 - taille;
	 $(".texte").css("fontSize", taille+"px");
});