JSFiddle - React, Tailwind, and code Playground

HTML

<div id='panel_wrapper'>
										<div id='flip'>Toolbox</div>
											<div id='panel'>
												<span id='panelMenuContainer1' class='panelMenuContainer'>
													<ul id='panelMenu1' class='panelMenu'>
														<li id='panelMenuItem1' class='panelMenuItem' onclick='showContentPanel(this.id)'>Text Pad</li>
														<li id='panelMenuItem2' class='panelMenuItem' onclick='showContentPanel(this.id)'>Calculator</li>
														<li id='panelMenuItem3' class='panelMenuItem' onclick='showContentPanel(this.id)'>Links</li>
													</ul>
												</span>
												<span>
													<div id='contentpanel1' class='content'>
														<textarea rows='10' cols='160'>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas rutrum, leo non sodales condimentum, leo tortor placerat tortor, sit amet lacinia orci leo sed arcu. Integer sit amet libero vel ipsum feugiat rutrum eget ac arcu. Nam posuere condimentum augue a iaculis. Aliquam rhoncus sagittis faucibus. Curabitur ornare, enim eu malesuada vulputate, magna metus rutrum eros, vitae accumsan quam neque eget arcu. Morbi ac lacus vitae elit lacinia lacinia at sit amet mi. Fusce posuere porta aliquam. Donec nec justo quis nisi convallis molestie. Cras rhoncus lacus sit amet dui lacinia vel consequat lacus iaculis. Nulla sit amet cursus massa. Mauris volutpat metus sit amet nulla fringilla vel commodo justo adipiscing. Ut et magna urna, ac placerat lorem. In ultricies augue eget turpis auctor molestie. Duis sollicitudin interdum nibh, vitae placerat est blandit nec. Pellentesque fermentum dignissim scelerisque. Phasellus tempus, lacus et suscipit blandit, elit erat viverra erat, sed tincidunt urna erat ut libero</textarea>
                                                        <button type="button">Test</button>
													</div>
													<div id='contentpanel3' class='content'>
														<br><br><br><a href='http://www.google.com' target='_blank'>Search</a><br><a...

JavaScript

YUI().use('panel', function (Y) {

    var panel = new Y.Panel({
        headerContent: 'Test Panel',
        bodyContent  : 'Some content here...',
        
        width   : 300,
        render  : '#test',
        centered: true,
        
        buttons: {
            header: ['close'],
            footer: [
                {
                    action  : 'hide',
                    label   : 'Bold Button',
                    template: '<button><strong class="yui3-button-label"></strong></button>'
                }
            ]
        }
    });

});