JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" class="switch_thumb">Switch Thumb</a>
    <div class="selecter">
        <div class="selecterBtns">
        <ul class="nolist">
            <li><a href="#" rel="test1" class="active">Test1</a></li>
            <li><a href="#" rel="test2">Test2</a></li>
            <li><a href="#" rel="test3">Test3</a></li>
        </ul>
    </div>
    <div class="selecterContent">
        <ul class="display">
            <li>Projet1</li>
            <li>Projet2</li>
            <li>…</li>
        </ul>
    </div>
</div>

CSS

ul {
    background-color : #aaf;
}

ul.thumb_view {
    background-color : #faa;
}

JavaScript

jQuery.cookie = function (key, value, options) {
if (arguments.length > 1 && String(value) !== "[object Object]") {
options = jQuery.extend({}, options);
if (value === null || value === undefined) {
options.expires = -1;
}
if (typeof options.expires === 'number') {
var days = options.expires, t = options.expires = new Date();
t.setDate(t.getDate() + days);
}
value = String(value);
return (document.cookie = [
encodeURIComponent(key), '=',
options.raw ? value : encodeURIComponent(value),
options.expires ? '; expires=' + options.expires.toUTCString() : '',
options.path ? '; path=' + options.path : '',
options.domain ? '; domain=' + options.domain : '',
options.secure ? '; secure' : ''
].join(''));
}
options = value || {};
var result, decode = options.raw ? function (s) { return s; } : decodeURIComponent;
return (result = new RegExp('(?:^|; )' + encodeURIComponent(key) + '=([^;]*)').exec(document.cookie)) ? decode(result[1]) : null;
};

$(document).ready(function(){
    if($.cookie("button")=="thumb_view"){
    $('ul.display').addClass($.cookie("button"));
    $("a.switch_thumb").addClass("swap");
    }else{
    $('ul.display').removeClass($.cookie("button"));
    $("a.switch_thumb").removeClass("swap");
    }
    
    var name="button";
    
    $("a.switch_thumb").click(function(){
        if($.cookie(name)!="thumb_view") {
            alert(1);
            $(this).addClass("swap");
            $("ul.display").fadeOut("fast", function() {
                $(this).fadeIn("fast").addClass("thumb_view");
            });
            $.cookie(name, "thumb_view");  
        }
        else {
            alert(2);
            $(this).removeClass("swap");
            $("ul.display").fadeOut("fast", function() {
                $(this).fadeIn("fast").removeClass("thumb_view");
            });
            $.cookie(name, "not_thumb_view");
        }
    });
});