在响应式Twitter Bootstrap视图中导致的空白区域

Question

我不确定div上方的这个空格是由媒体查询引起的，还是由twitter bootstrap css中的某些内容引起的。

以下是中间视图的页面：http://postimg.org/image/gq9dfuuah

以下是页面顶部的标记：

<div class="page-section intro">

<div class="container">
    <div class="logo"><img src="../../images/logo-2.png" id="backdrop"></div>
   <div class="intro_wrapper">
    <div class="row">
        <div class="col-md-6"><span class="pull-right">
            <div class="mockup">
            <img src="../../images/techandall_shadow_series_apple.png" id="backdrop">
            </div>
        </div></span>
        <div class="col-md-6">
        <span class="pull-right">
        <div class="saying">Design, Development, Dedication</div>
                <div class="left"><p class="lead center">We are highly experienced in Responsive Web Design, Database-driven websites, Content Management Systems, and Custom Web Applications.</p>
                </div>
            <div class="intro_buttons center-block">
                <div class="center_button">
                    <a href="#" class="scroll-link btn btn-dark" id="contact" data-id="">Get A Quote</a>
                </div>    
            </div>

        </div></span>
     </div>
    </div><!-- feature_wrapper -->
</div><!--/.container-->