Лайтбокс эффект для Bootstrap

<div class="container">
 <div class="col-xs-6 col-sm-3">
 <a href="#" class="thumbnail" data-toggle="modal" data-target="#lightbox">
 <img src="/6111422887_ddd199179a_b.jpg" alt="demo 1">
 </a>
 </div>
 <div class="col-xs-6 col-sm-3">
 <a href="#" class="thumbnail" data-toggle="modal" data-target="#lightbox">
 <img src="/9213448127_51823f78c8_b.jpg" alt="demo 2">
 </a>
 </div>
</div>
<div id="lightbox" class="modal fade" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel" aria-hidden="true">
 <div class="modal-dialog">
 <button type="button" class="close hidden" data-dismiss="modal" aria-hidden="true">×</button>
 <div class="modal-content">
 <div class="modal-body">
 <img src="/" alt="" />
 </div>
 </div>
 </div>
</div>

#lightbox .modal-content {
display: inline-block;
text-align: center;
}
#lightbox .close {
opacity: 1;
color: rgb(255, 255, 255);
background-color: rgb(25, 25, 25);
padding: 5px 8px;
border-radius: 30px;
border: 2px solid rgb(255, 255, 255);
position: absolute;
top: -15px;
right: -55px;
z-index:1032;
}

$(document).ready(function() {
 var $lightbox = $('#lightbox');
$('[data-target="#lightbox"]').on('click', function(event) {
 var $img = $(this).find('img'),
src = $img.attr('src'),
alt = $img.attr('alt'),
css = {
 'maxWidth': $(window).width() - 100,
 'maxHeight': $(window).height() - 100
 };
$lightbox.find('.close').addClass('hidden');
$lightbox.find('img').attr('src', src);
$lightbox.find('img').attr('alt', alt);
$lightbox.find('img').css(css);
 });
$lightbox.on('shown.bs.modal', function (e) {
 var $img = $lightbox.find('img');
$lightbox.find('.modal-dialog').css({'width': $img.width()});
$lightbox.find('.close').removeClass('hidden');
 });
});