function openBtnClick() {
  document.getElementsByClassName('tk_id_js-hamburger')[0].classList.toggle('tk_active');
  document.getElementsByClassName('tk_id_js-hamburger-close')[0].classList.toggle('tk_active');
  document.getElementsByClassName('tk_id_g-nav')[0].classList.toggle('tk_panel-active');
};

function closeBtnClick() {
  document.getElementsByClassName('tk_id_js-hamburger')[0].classList.toggle('tk_active');
  document.getElementsByClassName('tk_id_js-hamburger-close')[0].classList.toggle('tk_active');
  document.getElementsByClassName('tk_id_g-nav')[0].classList.toggle('tk_panel-active');
};

function menuBtnClick() {
  document.getElementsByClassName('tk_id_js-hamburger')[0].classList.remove('tk_active');
  document.getElementsByClassName('tk_id_js-hamburger-close')[0].classList.remove('tk_active');
  document.getElementsByClassName('tk_id_g-nav')[0].classList.remove('tk_panel-active');
};