Add class scroll up and scroll down the webpage

    <script>
        jQuery(document).ready(function(e) {
var position = jQuery(window).scrollTop();

// should start at 0
var x = jQuery("#pg-217-0").offset();
     var offt = x.top;
jQuery(window).scroll(function(e) {
    var scroll = jQuery(window).scrollTop();
   

    if(scroll < position && scroll > offt) {
        jQuery('#pg-217-0').addClass('stc');
    } else{
        
         jQuery('#pg-217-0').removeClass('stc');
    }
    position = scroll;
});
});
    </script>