https://purenas.jp/blog/wp-content/themes/pc_theme/js/pagetop.js

1$(function(){
2    var elm  = document.createElement('a');
3    elm.href = location.href;
4
5    var moveToTheTop = $('#move-to-the-top');
6
7    $(window).scroll(function() {
8        if ($(this).scrollTop() > 200) {
9            moveToTheTop.fadeIn(500);
10        } else {
11            moveToTheTop.fadeOut(500);
12        }
13    });
14
15    // Click Action
16    moveToTheTop.on('click' , function(event) {
17        event.preventDefault();
18        $('html, body').animate({scrollTop: 0}, 500);
19    });
20});
21
22// フッターバナー追従
23$(function() {
24    var $footer = $('.m-footer-fixed-box');
25    // Nav Fixed
26    $(window).scroll(function() {
27        if ($(window).scrollTop() > 100) {
28            $footer.addClass('scroll');
29        } else {
30            $footer.removeClass('scroll');
31        }
32    });
33});