$(function() {
    $('.gh-files .expander a').click(function(e) {
        e.preventDefault();
        var $this = $(this);
        var $li = $this.parents(".modified");
        var $diff = $li.find(".diff");
        if ($diff.is(":visible")) {
            $diff.slideUp(300, function() {
                $li.css({paddingBottom: '0'});
            });
        } else {
            $diff.slideDown(300, function() {
                $li.css({paddingBottom: '.5em'});    
            });
        }
    });
});