导航图标不会出现在真正的手机上

Question

我正在iPhone 5上测试我的代码而我的'导航图标'没有显示出来。当我使用chrome中的开发人员工具模拟移动视图时，它可以很好地工作，但是在真正的手机上却没有。

$(document).ready(function(){
	$('#nav-icon').click(function(){
		$(this).toggleClass('open');
	});
  
	// $('#nav-icon').on("click", function(){
	// 	  $("ul").toggleClass('open1');
	// });
  
      $("#nav-icon").click(function(){
        // $("ul").fadeToggle();
        $("ul").slideToggle(500);
        // $("#div3").fadeToggle(3000);
    });
});

nav {
  background-color: #252525;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #686868;
  font-size: 22px;
  border-radius: 5px 5px 0 0;
  font-family:arial;
}

.box-1,
.box-2,
.box-3 {
  flex: 1;
  height: 100%;
  display: flex;
  justify-content: center;
  letter-spacing: 2px;
}

.box-2 {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.box-1,
.box-2 {
  display: flex;
  align-items: center;
  grow-flex: 1;
}

ul {
  overflow: hidden;
  background-color: #505050;
  display: none;
  padding: 0;
  margin: 0;
  list-style: none;
  text-align: center;
  
  animation-name: test1;
  animation-duration: 1s;
  timing-function: ease-in-out;
  
  perspective: 1000px;
}

ul.open1 {
  height: auto;
  //background-color: red;
  animation-name: test;
  animation-duration: 500ms;
  animation-timing-function: ease-in-out;
}

@keyframes test {
  0% {opacity: 0;}
  transform: rotateY(-90deg)
  translateY(30px);
  
  100% {opacity: 1;}
  transform: rotateY(0deg) translateY(0px);
}

@keyframes test1 {
  0% {opacity: 100%;}
  100% {opacity: 0%;}
}



ul li {
  border-bottom: 1px solid #404040;
}

ul li a {
  color: #686868;
  font-size: 22px;
  text-decoration: none;
  display: block;
  padding: 10px;
}

li:hover {
  background: grey;
  color: #252525;
}

#nav-icon, #nav-icon2, #nav-icon3, #nav-icon4 {
  width: 60px;
  height: 45px;
  position: relative;
  margin: 4% auto;
  -webkit-transform: rotate(0deg);
  -moz-transform: rotate(0deg);
  -o-transform: rotate(0deg);
  transform: rotate(0deg);
  transition: .7s ease-in-out;
  cursor: pointer;
}

#nav-icon span, #nav-icon3 span, #nav-icon4 span {
  display: block;
  position: absolute;
  height: 9px;
  width: 100%;
  background: #686868;
  border-radius: 9px;
  opacity: 1;
  left: 0;
  -webkit-transform: rotate(0deg);
  -moz-transform: rotate(0deg);
  -o-transform: rotate(0deg);
  transform: rotate(0deg);
  transition: .5s ease-in-out;
}

#nav-icon span:nth-child(1) {
  top: 0px;
}

#nav-icon span:nth-child(2) {
  top: 18px;
}

#nav-icon span:nth-child(3) {
  top: 36px;
}

#nav-icon.open span:nth-child(1) {
  top: 18px;
  -webkit-transform: rotate(135deg);
  -moz-transform: rotate(135deg);
  -o-transform: rotate(135deg);
  transform: rotate(135deg);
}

#nav-icon.open span:nth-child(2) {
  opacity: 0;
  left: -60px;
}

#nav-icon.open span:nth-child(3) {
  top: 18px;
  -webkit-transform: rotate(-135deg);
  -moz-transform: rotate(-135deg);
  -o-transform: rotate(-135deg);
  transform: rotate(-135deg);
}

section {
  background-color: grey;
  border: solid 1px grey;
  padding: 2%;
}

@media (max-width: 480px) {
  .box-1,
  .box-2,
  .box-3 {
    font-size: 60%;
  }
  
  #nav-icon span, #nav-icon3 span, #nav-icon4 span {
    height: 7px;
    width: 80%;
  }
  
  #nav-icon span:nth-child(1) {
    top: 10px;
}

#nav-icon span:nth-child(2) {
  top: 22px;
}

#nav-icon span:nth-child(3) {
  top: 34px;
}
  
  .box-2 {
        border: solid 1px red;
  }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
  <nav>
    <div class="box-1">
      THE &lt;SNIP&gt;
    </div>
    
    <div class="box-2">
      <div id="nav-icon">
        <span></span>
        <span></span>
        <span></span>
      </div>
    </div>
    
    <div class="box-3">
      07429009478
    </div>
  </nav>
  
      <ul>
        <li><a href="#">Home</a></li>
        <li><a href="#">Portfolio</a></li>
        <li><a href="#">Contact</a></li>
      </ul>
</header>

<section>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ipsa facere dolor illum, voluptatum atque perspiciatis doloremque alias cupiditate a est sunt odio, repellat. Rerum et asperiores, necessitatibus aliquid minus, quia!</p>
</section>

需要帮助！

非常感谢！