$(document).ready(function () {

    // required elements
    var imgPopup = $('.img-popup');
    var imgCont = $('.container__img-holder');
    var popupImage = $('.img-popup img');
    var closeBtn = $('.close-btn');

    // handle events
    imgCont.on('click', function () {
        var img_src = $(this).children('img').attr('src');
        imgPopup.children('img').attr('src', img_src);
        imgPopup.addClass('opened');
    });

    $(imgPopup, closeBtn).on('click', function () {
        imgPopup.removeClass('opened');
        imgPopup.children('img').attr('src', '');
    });

    popupImage.on('click', function (e) {
        e.stopPropagation();
    });

});