JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://meyerweb.com/eric/tools/css/reset/reset.css">
<script src="http://cdnjs.cloudflare.com/ajax/libs/jquery-easing/1.3/jquery.easing.min.js"></script>
<body>
<div id="wrapper">
    <header class="cf">
        <h1>LOGO</h1>
        <nav>
            <ul class="slimmenu">
                <li><a href="#">Link 1</a></li>
                <ul>
                   <li>something</li>
                </ul>
                <li><a href="#">Link 2</a></li>
                <li><a href="#">Link 3</a></li>
                <li><a href="#">Link 4</a></li>
            </ul>
        </nav>
    </header>
</div>
</body>

CSS

/* page styles */
body {
    font-family: 'Lucida Sans Unicode', 'Lucida Console', sans-serif;
    padding: 0;
}       
#wrapper { 
    max-width: 860px; 
    margin: 0 auto; 
}
header {
    position: relative;
    background-color: #787f8a;
}
header h1 { 
    float: left; 
    color: #f2f2f2;
    padding: 15px 15px 10px 15px;
}
header nav { 
    float: right; 
}

/* clearfix */
.cf:before, .cf:after { content: ""; display: table; }
.cf:after { clear: both; }
.cf { *zoom: 1; }

/* slimmenu styles */
.menu-collapser {
    position: relative;
    background-color: #787f8a;
    color: #FFF;
    text-shadow: 0 1px 0 rgba(0,0,0,0.5);
    width: 100%;
    height: 48px;
    line-height: 48px;
    font-size: 16px;
    padding: 0 8px;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box
}
.collapse-button {
    position: absolute;
    right: 8px;
    top: 50%;
    width: 40px;
    background-color: #0E0E0E;
    background-image: linear-gradient(to bottom, #151515, #040404);
    background-repeat: repeat-x;
    border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
    border-radius: 4px 4px 4px 4px;
    border-style: solid;
    border-width: 1px;
    color: #FFFFFF;
    box-shadow: 0 1px 0 rgba(255, 255, 255, 0.1) inset, 0 1px 0 rgba(255, 255, 255, 0.075);
    padding: 7px 10px;
    text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.25);
    cursor: pointer;
    font-size: 14px;
    text-align: center;

    transform: translate(0, -50%);
    -o-transform: translate(0, -50%);
    -ms-transform: translate(0, -50%);
    -moz-transform: translate(0, -50%);
    -webkit-transform: translate(0, -50%);

    box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box
}
.collapse-button:hover, .collapse-button:focus {
    background-image: none;
    background-color: #040404;
    color: #FFF;
}
.collapse-button .icon-bar {
    background-color: #F5F5F5;
    border-radius: 1px 1px 1px 1px;
   ...

JavaScript

/**
 * jquery.slimmenu.js
 * http://adnantopal.github.io/slimmenu/
 * Author: @adnantopal
 * Copyright 2013, Adnan Topal (atopal.com)
 * Licensed under the MIT license.
 */
;(function ( $, window, document, undefined )
{
    var pluginName = "slimmenu",
        defaults =
        {
            resizeWidth: '768',
            collapserTitle: 'Main Menu',
            animSpeed: 'medium',
            easingEffect: null,
            indentChildren: false,
            childrenIndenter: '&nbsp;&nbsp;'
        };

    function Plugin( element, options )
    {
        this.element = element;
        this.$elem = $(this.element);
        this.options = $.extend( {}, defaults, options );
        this.init();
    }

    Plugin.prototype = {

        init: function()
        {
            var $options = this.options,
                $menu = this.$elem,
                $collapser = '<div class="menu-collapser">'+$options.collapserTitle+'<div class="collapse-button"><span class="icon-bar"></span><span class="icon-bar"></span><span class="icon-bar"></span></div></div>',
                $menu_collapser;

            $menu.before($collapser);
            $menu_collapser = $menu.prev('.menu-collapser');

            $menu.on('click', '.sub-collapser', function(e)
            {
                e.preventDefault();
                e.stopPropagation();

                var $parent_li = $(this).closest('li');

                if ($(this).hasClass('expanded'))
                {
                    $(this).removeClass('expanded');
                    $(this).find('i').html('&#9660;');
                    $parent_li.find('>ul').slideUp($options.animSpeed, $options.easingEffect);
                }
                else
                {
                    $(this).addClass('expanded');
                    $(this).find('i').html('&#9650;');
                    $parent_li.find('>ul').slideDown($options.animSpeed, $options.easingEffect);
                }
            });

           ...