stickUp它能让页面目标元素 “固定” 在浏览器窗口的顶部
<script type="text/javascript">
jQuery(function($) {
$(document).ready( function() {
//enabling stickUp on the '.navbar-wrapper' class
$('.page-navbar').stickUp({
});
});
});
</script>
<script src="js/stickUp.min.js"></script>