JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<button class="btn">Regular</button>
<button class="btn btn-large">Large</button>
<button class="btn btn-xlarge">Extra Large</button>

<br><br>

<button class="btn btn-primary">Regular</button>
<button class="btn btn-large btn-primary">Large</button>
<button class="btn btn-xlarge btn-primary">Extra Large</button>

<br><br>

<button class="btn btn-danger">Regular</button>
<button class="btn btn-large btn-danger">Large</button>
<button class="btn btn-xlarge btn-danger">Extra Large</button>

<br><br>

<button class="btn btn-block">Regular</button>
<button class="btn btn-block btn-large">Regular</button>
<button class="btn btn-block btn-xlarge">Regular</button>

CSS

/**
 * Extra large button extensions. Extends `.btn`.
 */
.btn-xlarge {
    padding: 18px 28px;
    font-size: 22px;
    line-height: normal;
    -webkit-border-radius: 8px;
       -moz-border-radius: 8px;
            border-radius: 8px;
    }


/**
 * Example base
 */
body {
    padding: 3em;
    }