$(document).ready(function(){
    $(".nav-link").each(function(){
        var url = window.location.href;
        var pattern = /page.*/;
        url = url.replace(pattern,"");
        url2 = $("#single-post-category").children("a").attr("href");
        if(($(this).children("a").attr("href")+"/") == url ||
                ($(this).children("a").attr("href")+"/") == url2){
            $(this).css("backgroundPosition", "0 45px");
            return;
        }
    });
});