JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="ru" lang="ru">
    <head>
        <base href="http://www.xn----jtbhjbegmdlrup.xn--p1ai/" />
        <title>
            Офис Комплект :: Главная        </title>
        <meta http-equiv="Content-Type" content="application/xhtml+xml; charset=utf-8" />
        <meta name="keywords" content="мебель для офиса офисная Екатеринбург офисные столы компьютерные кресла стулья руководителя кабинет Главная страница компании Офис Комплект " />
        <meta name="description" content="Магазин офисной мебели Главная страница компании Офис Комплект " />
        <meta name="Developer" content="http://www.itex.ru" />
        <meta name='yandex-verification' content='4d8f6d1b5671667f' />
        <style type="text/css" media="screen, projection, print">@import url("style.css");</style>
<style type="text/css" media="screen, projection, print">@import url("http://www.xn--e1aahbxctdme.xn--p1ai/2/stylek.css");</style>
        <style type="text/css" media="screen, projection, print">@import url("mod/highslide/highslide.css");</style>
        <script type="text/javascript" src="http://www.xn--e1aahbxctdme.xn--p1ai/2/javascript.js"></script>
        <script type="text/javascript" src="mod/jquery/jquery.js"></script>
        <script type="text/javascript" src="mod/highslide/highslide-full.js"></script>
        <script type="text/javascript" src="mod/highslide/highslide-init.js"></script>
        <link rel="stylesheet" href="mod/lightbox/css/jquery.lightbox-0.5.css" type="text/css" media="screen" />
        <script src="mod/lightbox/js/jquery.lightbox-0.5.pack.js" type="text/javascript"></script>
        <script type="text/javascript" src="js/func.js"></script>
        <script type="text/javascript">
            hs.align = 'center';
            hs.dimmingOpacity = 0.7;
            hs.dimmingDuration = 200;
           ...

CSS

#link {
    width: 309px;
    display:block;
    border:0px solid #ccc;
    border-radius:0px;
    padding:0px;
}
#link.active {
    width: 309px;
    border-bottom:0;
    border-radius: 0px 0px 0 0;
}
#test {
    width: 309px;
    border:1px solid #ccc;
    border-top:0;
    border-radius: 0 0 0px 0px ;
    padding:0px;
    display:none;
}

JavaScript

window.onload = function(){
    document.getElementById("link").onclick = function(){
        if(/active/.test(this.className)){
            this.className = "";
            document.getElementById("test").style.display = "none";
        }else{
            this.className = "active";
            document.getElementById("test").style.display = "block";
        }
    
    }
};