$(document).ready(function() {
    var throttleTimeout;


    $('#fullPage').fullpage({
        scrollOverflow: true,
        scrollOverflowOptions: {
            mouseWheel: true,
            mouseWheelSpeed: 50,
            scrollbars: true
        },
        normalScrollElements: '.scrollable-content',
        responsiveWidth: 900,
        onLeave: function(index, nextIndex, direction) {
            var scrollingSpeed = 700; 
            if (direction === 'up' || direction === 'down') {
                $.fn.fullpage.setScrollingSpeed(scrollingSpeed);
            }
            if (nextIndex === 1) {
                $('header h1>img').attr('src','/base/img/main/header/logo.svg');
                $('header .language-wrap img').attr('src','/base/img/main/header/lang.png');
$('#nav-button').css({
                'background':'url(/base/img/main/header/nav-icon.png) no-repeat 0 0',
                'background-size':'cover'
            });
                $('header').removeClass('on');
            } else {
                $('header h1 img').attr('src','/base/img/main/header/logo-bk.png');
                $('header .language-wrap img').attr('src','/base/img/main/header/lang-bk.png');
                $('#nav-button').css({
                    'background':'url(/base/img/main/header/nav-icon-bk.png) no-repeat 0 0',
                    'background-size':'cover'
                });
                $('header').addClass('on');
            }
        }
    });


    $(window).on('scroll', function() {
        clearTimeout(throttleTimeout);
        throttleTimeout = setTimeout(function() {
        }, 250); 
    });
});