Add customize button to new LJ navigation

gistfile1.txt

// ==UserScript==
// @name         Customize button in new nav
// @namespace    http://yoksel.ru/
// @version      0.1
// @description  Add customize button to new LJ navigation
// @author       You
// @include        *livejournal.com*
// @include        *livejournal.ru*
// @grant        none
// ==/UserScript==

var doc = document;
var ljPageNav = doc.querySelector('.s-nav-body');

if ( !ljPageNav ) {
    return;
}

// Detect domain
var domain = "livejournal.com";
var hostname = document.location.hostname;
if (hostname.indexOf("ljdev") >= 0){
    var urlParts = hostname.split(".");
    for (var i = 0; i < urlParts.length; i++){
        var item = urlParts[i];
        if(item.indexOf("ljdev") >= 0 ){
            domain = item + ".livejournal.ru"
        }
    }
}

// Add link to customize theme in controlstrip
var elem = "";
var customize_url = "http://" + domain + "/customize/options.bml";

var usernameElem = doc.querySelector('.s-header-journal__user .i-ljuser-type-C');
var username = '';

if ( usernameElem ) {
    username = usernameElem.innerText.toLowerCase();
    customize_url += '?authas=' +username
}

var newItem = doc.createElement('li');
newItem.classList.add('s-nav-item');
newItem.classList.add('header-item');
newItem.innerHTML = '<a href=\''+ customize_url +'\' class=\'s-header-item__link\' target=\'_blank\'>Настроить стиль журнала</a>';

var newItemElem = ljPageNav.appendChild(newItem);