var details = document.querySelectorAll("details");
for(i=0;i<details.length;i++) {
	details[i].addEventListener("toggle", accordion);
}
function accordion(event) {
  if (!event.target.open) return;
	var details = event.target.parentNode.children;
	for(i=0;i<details.length;i++) {
		if (details[i].tagName != "DETAILS" || !details[i].hasAttribute('open') || event.target == details[i]) continue;
		details[i].removeAttribute("open");
	}
}