Set Bootstrap navbar transparency on scroll

Question

I use a secondary fille called custom.css to overwrite the bootstrap code and I would like to know how to create a code that is activating only when the visitor of my site i

Answer 1

$(document).ready(function() {
    $(window).scroll(function() {
       if($(this).scrollTop() > height) { 
           $('.navbar').addClass('scrolled');
       } else {
           $('.navbar').removeClass('scrolled');
       }
    });
});