$(document).ready(function() {
var sectionIds = $('a.nav-link');
$(document).scroll(function() {
sectionIds.each(function() {
var container = $(this).attr('href');
var containerOffset = $(container).offset().top;
var containerHeight = $(container).outerHeight();
var containerBottom = containerOffset + containerHeight;
var scrollPosition = $(document).scrollTop();
if (scrollPosition < containerBottom - 350 && scrollPosition >= containerOffset - 350) {
$(this).addClass('active');
} else {
$(this).removeClass('active');
}
});
});
});