https://hyogopulp.co.jp/js/scroll.js

1// JavaScript Document
2// Easingの追加
3jQuery.easing.quart = function (x, t, b, c, d) {
4    return -c * ((t=t/d-1)*t*t*t - 1) + b;
5};
6 
7/*-------------------------------------
8 ページ読み込み中
9-------------------------------------*/
10jQuery(document).ready(function(){
11 
12    //
13    // <a href="#***">の場合、スクロール処理を追加
14    //
15    jQuery('a[href*=#]').click(function() {
16        if (location.pathname.replace(/^\//,'') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname) {
17            var $target = jQuery(this.hash);
18            $target = $target.length && $target || jQuery('[name=' + this.hash.slice(1) +']');
19            if ($target.length) {
20                var targetOffset = $target.offset().top;
21                jQuery('html,body').animate({ scrollTop: targetOffset }, 500, 'quart');
22                return false;
23            }
24        }
25    });
26 
27});