https://www.salon-oeste.de/wp-content/themes/ark/assets/plugins/jquery.back-to-top.js?ver=5.3.25

1(function($){
2
3$(document).ready(function($){
4    // browser window scroll (in pixels) after which the "back to top" link is shown
5    var offset = 300,
6        //browser window scroll (in pixels) after which the "back to top" link opacity is reduced
7        offset_opacity = 1200,
8        //duration of the top scrolling animation (in ms)
9        scroll_top_duration = 700,
10        //grab the "back to top" link
11        $back_to_top = $('.js-back-to-top');
12
13    //hide or show the "back to top" link
14    $(window).scroll(function(){
15        ( $(this).scrollTop() > offset ) ? $back_to_top.addClass('back-to-top-is-visible') : $back_to_top.removeClass('back-to-top-is-visible back-to-top-fade-out');
16        if( $(this).scrollTop() > offset_opacity ) {
17            $back_to_top.addClass('back-to-top-fade-out');
18        }
19    });
20
21    //smooth scroll to top
22    $back_to_top.on('click', function(event){
23        event.preventDefault();
24        $('body,html').animate({
25            scrollTop: 0
26            }, scroll_top_duration
27        );
28    });
29});
30})(jQuery);