https://www.runanempire.com/wp-content/themes/rae-theme/js/jquery.responsivesticky.js

1(function ( $ ) {
2  
3  // Default settings, you should change them by calling the .prettyfit function
4  var settings = {
5    destroy: false
6
7  };
8
9  $.fn.responsivesticky = function (options) {
10    // Override default settings
11    if (options) {
12      settings = $.extend(settings, options);
13    }
14
15    // The for each is needed to treat each element
16    return this.each(function() {
17
18      var stickyDiv = jQuery(this);
19
20      if (!settings.destroy) {
21
22        var maxscrollheight = (jQuery(stickyDiv).parent().offset().top + jQuery(stickyDiv).parent().outerHeight()) - (jQuery(stickyDiv).outerHeight() + 50);
23
24        if(jQuery(window).scrollTop() + 50 > jQuery(stickyDiv).parent().offset().top && jQuery(window).scrollTop() < maxscrollheight) {
25          sticky(stickyDiv);
26        }
27
28        jQuery(window).scroll(function(){ // scroll event
29
30          if (jQuery(window).scrollTop() + 50 > jQuery(stickyDiv).parent().offset().top && jQuery(window).scrollTop() < maxscrollheight && !settings.destroy) {
31            sticky(stickyDiv);
32          } else if (jQuery(window).scrollTop() > maxscrollheight && !settings.destroy) {
33            stickyAtTheBottom(stickyDiv);
34          } else {
35            stickyReset(stickyDiv);
36          }
37
38        });
39
40      } else {
41        stickyReset(stickyDiv);
42      }
43
44    });
45
46  };
47
48  function sticky(stickyDiv) {
49
50    var stickyMarginTop = 50;                       
51    jQuery(stickyDiv).css({'top': stickyMarginTop, 'position': 'fixed', 'left': jQuery(stickyDiv).offset().left});
52    
53  }
54
55  function stickyAtTheBottom(stickyDiv) {
56
57    jQuery(stickyDiv).removeAttr("style");
58    jQuery(stickyDiv).css({'bottom': 0, 'position': 'absolute'});
59
60  }
61
62  function stickyReset(stickyDiv) {
63
64    jQuery(stickyDiv).css({'top': 0, 'left': 0, 'position': 'relative'});
65
66  }
67
68}( jQuery ));