chech wieport

gistfile1.txt

const $vacansies = $(".vacancies-section__holder");
	let   $bottom;

    $(window).on('scroll', function () {
        $bottom	 = $vacansies.offset().top + $vacansies.height();
        if ($(window).scrollTop() - $bottom > 0 ) {
            $('.filter-block').addClass('fixed');
        } else $('.filter-block').removeClass('fixed');
    });

//safari support

function checkView(elem) {
if (window.pageYOffset - elem.offsetTop < elem.offsetHeight/2 + 300) {
elem.classList.add('animate-scroll');
}
if (window.pageYOffset - elem.offsetTop < -elem.offsetHeight/2 - 300) {
elem.classList.remove('animate-scroll');
}
}