var ACTIVE = 'active';
$(".main-navigation > ul > li").on('click', function() {
let clickedElementIsActive = $(this).hasClass(ACTIVE);
$(".main-navigation > ul > li").removeClass(ACTIVE);
clickedElementIsActive ? $(this).removeClass(ACTIVE): $(this).addClass(ACTIVE);
});
var ACTIVE = 'active';
$(".main-navigation > ul > li").on('click', function() {
$(this).toggleClass(ACTIVE);
});
var ACTIVE = 'active';
$(".main-navigation > ul > li").on('click', function() {
$(".main-navigation > ul > li").removeClass(ACTIVE);
$(this).toggleClass(ACTIVE);
});