JS (themes/redesign/custom-js/filters-pane.js)

document.querySelector(document).addEventListener('ready', function () {
    let filterChooseBlock = document.querySelector('.catalog__goods-pane-filter-choose-wrap'),
        animationDuration = 300,
        isScrolled = false;

    arrowVisibility();

    filterChooseBlock.addEventListener('scroll', () => {
        arrowVisibility();
    });

    if (isScrollActive()) {
        document.querySelector('.filterPaneBlock').classList.add('scrollActive');
    }

    filterChooseBlock.addEventListener('scroll', () => {
        if (!isScrolled) {
            gaWrapper.ga('send', 'event', 'Products-Filter', 'filter-tab-scroll');

            isScrolled = true;
        }
    })

    if (typeof ResizeObserver === 'function') {
        let resizeObserver = new ResizeObserver(() => {
            arrowVisibility();

            if (isScrollActive()) {
                document.querySelector('.filterPaneBlock').classList.add('scrollActive');

                return;
            }

            document.querySelector('.filterPaneBlock').removeClass('scrollActive');
        });

        resizeObserver.observe(document.getElementsByClassName('catalog__goods-pane-filter-choose-wrap')[0]);
    }

    document.querySelector('.clickLeftBlock').addEventListener('click', () => {
        filterChooseBlock.finish()
        filterChooseBlock.animate({scrollLeft: filterChooseBlock.scrollLeft() - 100},
            animationDuration,
            arrowVisibility);
    });
    document.querySelector('.clickRightBlock').addEventListener('click', (event) => {
        filterChooseBlock.finish()
        filterChooseBlock.animate({scrollLeft: filterChooseBlock.scrollLeft() + 100},
            animationDuration,
            arrowVisibility);
    });

    document.querySelector('.select-sort-current').addEventListener('click',  (event) => {
        if (globalUI.isMobile && !document.querySelector('.select-sort_open').length) {
            event.stopPropagation();
            sortSelectPopUp();
        }
    });
});

function sortSelectPopUp() {
    if (document.querySelector('.select-sort_open').length) {
        return;
    }

    let sortSelect =  document.querySelector('.catalog__sort-form-mobile');

    document.querySelector('body').insertAdjacentHTML("beforeend",'<span class="darkMask"></span>');
    sortSelect.css('display', 'block');

    document.querySelector(document).addEventListener('click', (event) => {
        if (!document.querySelector(event.target).closest('.catalog__sort-form-mobile').length) {
            sortSelect.css('display', 'none');
            document.querySelector('.darkMask').remove();

            gaWrapper.ga('send', 'event', 'Products-Sort', 'sort-option', 'deactivate');
        }
    })
}

function arrowVisibility() {
    let filterChooseBlock = document.querySelector('.catalog__goods-pane-filter-choose-wrap'),
        rightSelector = document.querySelector('.clickRightBlock'),
        leftSelector = document.querySelector('.clickLeftBlock');

    if (isScrollActive()) {
        if (filterChooseBlock.get(0).scrollWidth - filterChooseBlock.scrollLeft() <= filterChooseBlock.outerWidth()) {
            rightSelector.css('visibility', 'hidden');
        } else {
            rightSelector.css('visibility', 'visible');
        }

        if (filterChooseBlock.scrollLeft() === 0) {
            leftSelector.css('visibility', 'hidden');
        } else {
            leftSelector.css('visibility', 'visible');
        }

        return;
    }

    rightSelector.css('visibility', 'hidden');
    leftSelector.css('visibility', 'hidden');
}

function isScrollActive() {
    let element = document.querySelector('.catalog__goods-pane-filter-choose-wrap').get(0);

    return element.scrollWidth > element.clientWidth;
}

function sortListBorderColorChange(currentPageUrl) {
    let borderColorSelected = '#1A77D2',
        selectSortClass = '.select-sort';

    if (localStorage.getItem('sortPage') === currentPageUrl) {
        document.querySelector(selectSortClass).css('border-color', borderColorSelected);

        return;
    }

    document.querySelector('.select-sort-mobile, .select-sort li').addEventListener('click', () => {
        document.querySelector(selectSortClass).css('border-color', borderColorSelected);
        localStorage.setItem('sortPage', currentPageUrl);
    });
}