JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://dl.dropbox.com/u/1722364/Stack%20Overflow/jquery-ui.css">
<div id="debug">
    jQuery UI will be applied to these buttons after a 5 second timeout
</div>
<div class="example">
    This is what happens with the button class to
    emulate jQuery UI <b>without running jQuery UI</b>
    <br/>
    <a class="button" href="#">&lt;a/&gt;</a>
    <button class="button" type="button">&lt;button/&gt;</button>
    <input class="button" type="button" value="&lt;input/&gt;"/>
    <div style="padding:10px 0 0 40px; color:red;">NB: this is pure css emulation using the "button" class, no javascript!</div>
</div>
<div class="example">
    This is what happens when you use the button class to
    <b>emulate jQuery UI until it loads</b>
    <br/>
    <a class="button apply-ui-after-delay" href="javascript:;">&lt;a/&gt;</a>
    <button class="button apply-ui-after-delay" type="button">&lt;button/&gt;</button>
    <input class="button apply-ui-after-delay" type="button" value="&lt;input/&gt;"/>
</div>
<div class="example">
    This is what we'd get if we apply the UI classes ahead of time
    <br/>
    <a class="apply-ui-after-delay ui ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" href="javascript:;">&lt;a/&gt;</a>
    <button class="apply-ui-after-delay ui ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only">&lt;button/&gt;</button>
    <input class="apply-ui-after-delay ui ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" type="button" value="&lt;input/&gt;"/>
</div>
<div class="example">
    And this is the worst case scenario...
    <br/>
    <a class="apply-ui-after-delay" href="javascript:;">&lt;a/&gt;</a>
    <button class="apply-ui-after-delay">&lt;button/&gt;</button>
    <input class="apply-ui-after-delay" type="button" value="&lt;input/&gt;"/>
</div>
<div class="example">
    <b>NB.: If you want the css to apply to all buttons and not only the ones with the "button"...

CSS

/* ignore this css, I'm just making the demo readable */
body{padding:20px;font-size:9.0pt;font-family:Arial;}
.example{border-top:#ccc dotted 2px;margin-bottom:15px;padding-top:10px;}
#debug{padding:10px;background:#fc0;color:#900;font-weight:bold;}

/* the css you need is below this line */
.button{
    cursor:pointer;
    display:inline-block;
    
    line-height:1.4;
    margin: 0 0.1em 0 0;
    padding: 0.3em 1em 0.4em;
    border: 1px solid #ccc;

    border-radius: 3px;
    -moz-border-radius: 3px;
    -webkit-border-radius: 3px;
    
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.1), 0 0 1px #FFF inset;
    -moz-box-shadow: 0 1px 0 rgba(0, 0, 0, 0.1), 0 0 1px #FFFFFF inset;
    -webkit-box-shadow: 0 1px 0 rgba(0, 0, 0, 0.1), 0 0 1px #FFF inset;
    
    color: #666;
    background: #EFEFEF;

    text-decoration: none;
    text-align: center;
    font-family: Segoe UI, Trebuchet MS, Tahoma, Arial, sans-serif;
    font-size:1.1em;
}
.button:hover{
	background-color:#f9f9f9;	
    border-color:#999999;
    color: #212121;
}
.button:active{
	background-color:#71B800;	
    border-color:#64A300;
    color: #ffffff;
}

JavaScript

setTimeout(function() {
    $('#debug').html('Pausing so you can see the difference');
    alert('jQuery UI is going to do its thing now, watch closely!');
    $('#debug').html('Invoking jQuery UI now!');
    $('.apply-ui-after-delay').removeClass('button').button();
    $('#debug').html('jQuery UI has been applied to this page')
}, 4000);