JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<h1>This is working</h1>
<div class="row">
    <div class="span6">Content</div>
    <div class="span6">Content</div>
    <div class="span6">Content</div>
    <div class="span6">Content</div>
</div>


<h1>This is NOT working</h1>
<div class="row-fluid">
    <div class="span6">Content</div>
    <div class="span6">Content</div>
    <div class="span6">Content</div>
    <div class="span6">Content</div>
</div>

CSS

.span6{ background: #989898; margin-botton: 20px; }

JavaScript

hi