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(function () {
 var toggleBtn = $('.js-hamburger'),
  nav = $('.js-nav');

 toggleBtn.on('click', function () {
  $(this).toggleClass('is-active');
  nav.toggleClass('is-active');
 });

 initNavTransition();

 $(window).resize(function () {
  initNavTransition();
  toggleBtn.removeClass('is-active');
  nav.removeClass('is-active');
 });

 function initNavTransition() {
  if ($(window).width() <= 767) {
   nav.css('transition', 'all 0.4s');
  } else {
   nav.css('transition', 'none');
  }
 }
})();