var acc = document.getElementsByClassName("accordion");

        for (var i = 0; i < acc.length; i++) {
          acc[i].addEventListener("click", function() {
            this.classList.toggle("active");
            this.parentElement.classList.toggle("active-accordion");
            var panel = this.nextElementSibling;
            if (panel.style.maxHeight) {
              panel.style.maxHeight = null;
            } else {
              panel.style.maxHeight = panel.scrollHeight + "px";
            }
          });
        }