JSFiddle - React, Tailwind, and code Playground

HTML

<div  class="lang-main showondesk">111</div>

		<div class="lang-two lang-two-off">111</div>

CSS

.lang-two-on {font-size:300px}
.lang-on {font-size:300px}

JavaScript

$(".lang-main").click(function () {
	   			$(this).toggleClass("lang-on");
	   			if ($(`.lang-two`).hasClass('lang-two-off')) {
            $('.lang-two').removeClass('lang-two-on').addClass('lang-two-off');
            
        } else {
            $('.lang-two').addClass('lang-two-on').removeClass('lang-two-off'); }
            

	});