open() {
const list = this.elem.parentNode.querySelector('.inset-list');
this.elem.classList.add('open');
+ this.elem.setAttribute('aria-expanded', 'true');
slideDown(list, 240);
}
close() {
const list = this.elem.parentNode.querySelector('.inset-list');
this.elem.classList.remove('open');
+ this.elem.setAttribute('aria-expanded', 'false');
slideUp(list, 240);
}