JSFiddle - React, Tailwind, and code Playground

HTML

<div id="banner">
    <ul>
        <li>
            <a href="#" class="box">Design</a>
            <div class="sliderContent">
                <a class="closeButton" href="#">Close</a>
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            </div>
        </li>
        <li>
            <a href="#" class="box">Development</a>
            <div class="sliderContent">
                <a class="closeButton" href="#">Close</a>
                Lorem Ipsum Doner
            </div>
        </li>
        <li>
            <a href="#" class="box">Graphics</a>
            <div class="sliderContent">
                <a class="closeButton" href="#">Close</a>
                Lorem Ipsum Doner
            </div>
        </li>
    </ul>
</div>

CSS

a { color:#C30; text-decoration:none; }
    #banner { width: 930px; background-color:#666; height: 500px; }
    #banner ul { list-style:none; padding: 40px; }
    #banner ul li { margin: 10px 0 0 0; }
    #banner ul li a { border:5px solid #fff; background-color:#FC9; padding:10px; font: bold italic 18px Verdana; display:inline-block; }
    .sliderContent { background-color:#FC9; padding:10px; min-height: 150px; display:none; border:5px solid #fff; border-top: none; }
    .sliderContent a { padding:0 !important; border:none !important; }
    .sliderContent a.closeButton { background:url(icon_modal_close.png) no-repeat 0 0; float:right; height:30px; width:30px; text-indent:-999px; }
    .sliderContent a:hover .closeButton { background-position: 20px 0; }

JavaScript

$(document).ready(function() {
        $('a.box').click(function(event){
            event.preventDefault();
            var sliderContent = $(this).next('.sliderContent');
            $('.sliderContent').not(sliderContent).hide();
            $('a.box').not(this).css({'display':'inline-block', 'border':'5px solid #fff'});
                
            if (sliderContent.css("display") === "none") {
                $(this).css({'display':'block','border-bottom':'none'});
                sliderContent.show();
            } else {
                $(this).css({'display':'inline-block', 'border':'5px solid #000'});
                sliderContent.hide();
            };
            
        });
        $('.closeButton').click(function(event){
            event.preventDefault();
            $(this).parent().hide();
        });
    });