JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.1.1/css/bootstrap.min.css">
<div class="container">
    <div class="row">
        <div class="col-xs-6"><i></i></div>
        <div class="col-xs-6"><i></i></div>
        <div class="col-xs-12">
            <div class="row">
                <div class="col-xs-6">
                    <div class="row">
                        <div class="col-xs-12"><i></i></div>
                        <div class="col-xs-12"><i></i></div>
                    </div>
                </div>
                <div class="col-xs-6"><i></i></div>
            </div>
        </div>
    </div>
</div>

CSS

div {
    background:rgba(0, 0, 0, 0.2);
    border: 1px solid #000;
}
i {
    border: 1px solid blue;
    display:block;
    height: 200px;
}