CSS Auto Column separators

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css">
<body>
    <div class="container">
        	<h1>CSS Column Separators</h1>

        <p class="text-info">Hover over any column to enlarge</p>
        <div class="row">
            <div class="span2 border-right">
               	<h2>Left</h2>
                <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, 
                    sed do eiusmod tempor incididunt ut labore et dolore.</p>
                <p class="show-hover">Lorem ipsum dolor sit amet, consectetur 
                    adipisicing elit, sed do eiusmod tempor incididunt ut labore 
                    et dolore. Duis aute irure dolor.</p>
                <p class="show-hover">Lorem ipsum dolor sit amet, consectetur
                    adipisicing elit, sed do eiusmod tempor incididunt ut
                    labore et dolore. Duis aute irure dolor in reprehenderit
                    in voluptate velit esse cillum dolore eu fugiat nulla pariatur.</p>
            </div>
            <div class="span8 border-left border-right">
               	<h2>Main</h2>
                <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, 
                    sed do eiusmod tempor incididunt ut labore et dolore magna 
                    aliqua. Ut enim ad minim veniam, quis nostrud exercitation 
                    ullamco laboris nisi ut aliquip ex ea commodo consequat. 
                    Duis aute irure dolor in reprehenderit in voluptate velit
                    esse cillum dolore eu fugiat nulla pariatur. Excepteur sint
                    occaecat cupidatat non proident, sunt in culpa qui officia
                    deserunt mollit anim id est laborum.</p>
                <p class="show-hover">Lorem ipsum dolor sit amet, consectetur
                    adipisicing elit. Voluptatum, suscipit, dolorem, quidem,
                    numquam esse alias rerum quas consectetur sapiente...

CSS

.border-right, .border-left, .border-both {
    position: relative;
}
.border-left:before, .border-right:after {
    position: absolute;
    content:'';
    height: auto;
    top: 50px;
    bottom: 10px;
    border-right: 1px solid #aaa;
    width: 0;
}
.border-left:before { left: -11px; }
.border-right:after { right: -10px; }

.show-hover {
    display: none;
}
div:hover>.show-hover {
    display: block;
}