addEventListenerで登録したクリックイベントがiOSで発火しない

前提・実現したいこと

javascriptでモーダルを実装していますが、iOSでのみモーダルを表示するクリックイベントが発生しません。

該当のソースコード

codepen
https://codepen.io/mycreatesite/pen/YbKvQL

html
1<button id="openModal">Open modal</button>
2
3<section id="modalArea" class="modalArea">
4  <div id="modalBg" class="modalBg"></div>
5  <div class="modalWrapper">
6    <div class="modalContents">
7      <h1>Here are modal without jQuery!</h1>
8      <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. </p>
9    </div>
10    <div id="closeModal" class="closeModal">
11      ×
12    </div>
13  </div>
14</section>

css
1* {
2  box-sizing: border-box;
3}
4body {
5  font-family:'Avenir','Helvetica, Neue','Helvetica','Arial';
6}
7
8.modalArea {
9  visibility: hidden;
10  opacity : 0;
11  position: fixed;
12  z-index: 10;
13  top: 0;
14  left: 0;
15  width: 100%;
16  height: 100%;
17  transition: .4s;
18}
19
20.modalBg {
21  width: 100%;
22  height: 100%;
23  background-color: rgba(30,30,30,0.9);
24}
25
26.modalWrapper {
27  position: absolute;
28  top: 50%;
29  left: 50%;
30  transform:translate(-50%,-50%);
31  width: 70%;
32  max-width: 500px;
33  padding: 10px 30px;
34  background-color: #fff;
35}
36
37.closeModal {
38  position: absolute;
39  top: 0.5rem;
40  right: 1rem;
41  cursor: pointer;
42}
43
44.is-show {
45  visibility: visible;
46  opacity : 1;
47}
48
49button {
50  padding: 10px;
51  background-color: #fff;
52  border: 1px solid #282828;
53  border-radius: 2px;
54  cursor: pointer;
55}
56
57#openModal {
58  position: absolute;
59  top: 50%;
60  left: 50%;
61  transform:translate(-50%,-50%);
62}

js
1(function () {
2  const modalArea = document.getElementById('modalArea');
3  const openModal = document.getElementById('openModal');
4  const closeModal = document.getElementById('closeModal');
5  const modalBg = document.getElementById('modalBg');
6  const toggle = [openModal,closeModal,modalBg];
7  
8  for(let i=0, len=toggle.length ; i<len ; i++){
9    toggle[i].addEventListener('click',function(){
10      modalArea.classList.toggle('is-show');
11    },false);
12  }
13}());