Sticky Nav V3 - no jumps on short pages and responsive

global.js

/* Sticky navigation bar - Make the navigation area float after scrolling past it */

var aboveHeight = $('#primary-navigation').offset().top;

jQuery(window).scroll(function () {
 if ($(window).scrollTop() > aboveHeight && $(window).width() > 780) {

        $('.header').css({
            'position': 'fixed',
            'top': -90,
            'left': 0,
            'right': 0,
            'z-index': 9999,
            'max-width': 1200,
            'text-align': 'center',
            'border-radius': 0
        });

        $('.top').css({
            'padding-bottom': ($('.header').outerHeight(true) + 90)
        });

        if ($('#wpadminbar').length) {
            $('.header').css('margin-top', '32px');
        };


    } else {

        // resets back to what it should be, before the JS change.. 

        $('.header').css({
            'position': '',
            'top': '',
            'z-index': '',
            'border-radius': '',
            'max-width': ''
        });

        $('.top').css({
            'padding-bottom': 0
        });

    }
});