6 返回顶部html代码.MD

    <div id="scroll_to_top" class="d-fixed" style="position: fixed; _position: absolute; bottom: 80px; right: 110px; width: 70px; height: 70px; display: none;">
        <a href="javascript:void(0);" style="width: 70px; height: 70px; display: inline-block; background: url(static/scroll_top.png) no-repeat; outline: none;" title="返回顶部"></a>
    </div>

    <script>
    // 返回顶部
    var jscroll_to_top = $('#scroll_to_top');
    $(window).scroll(function() {
        if ($(window).scrollTop() >= 500) {
           jscroll_to_top.fadeIn(300);
        } else {
            jscroll_to_top.fadeOut(300);
        }
    });

    jscroll_to_top.on('click', function() {
        $('html,body').animate({scrollTop: '0px' }, 100);
    });
    </script>