获取div距离当前窗口顶部距离
$(window).scroll( function (){
var topPin =$('.graphic_box').offset().top - $(window).scrollTop();
console.log(topPin)
});
获取div距离当前窗口底部距离
$(window).scroll( function (){
var topPin =$('.faq_big_box').height() - $(window).scrollTop() - $(window).height();
console.log(topPin)
});