//according to loftblog tut $('.nav li:first').addClass('active');

var showSection = function showSection(section, isAnimate) { var direction = section.replace(/#/, ''), reqSection = $('.section').filter('[data-section="' + direction + '"]'), reqSectionPos = reqSection.offset().top - 0;

if (isAnimate) { $('body, html').animate({ scrollTop: reqSectionPos }, 800); } else { $('body, html').scrollTop(reqSectionPos); }

};

var checkSection = function checkSection() { $('.section').each(function () { var $this = $(this), topEdge = $this.offset().top - 80, bottomEdge = topEdge + $this.height(), wScroll = $(window).scrollTop(); if (topEdge < wScroll && bottomEdge > wScroll) { var currentId = $this.data('section'), reqLink = $('a').filter('[href*=\\#' + currentId + ']'); reqLink.closest('li').addClass('active'). siblings().removeClass('active'); } }); };

$('.main-menu, .responsive-menu, .scroll-to-section').on('click', 'a', function (e) { e.preventDefault(); showSection($(this).attr('href'), true); });

$(window).scroll(function () { checkSection(); });