Fixed width right column with fluid left column

by soulwire

HTML

<div class="wrapper">
    <article class="post">
        <div class="body">
            Body
        </div>
        <header>
            <h1>Header</h1>
        </header>
    </article>
</div>

CSS

.wrapper {
    border: 1px solid red;
    margin: 0 auto;
    max-width: 400px;
}

article {
    overflow: hidden;
}

header {
    border: 1px solid green;
}

.body {
    border: 1px solid blue;
    width: 100px;
    float: right;
}

JavaScript

var $wrapper = $( '.wrapper' );
var $template = $( '.post' );

for ( var i = 0; i < 10; i++ ) {
    $wrapper.append( $template.clone() );
}