CSS3 simulated side sliding menu_html/css_WEB-ITnose

<nav>        <div id="toggleMenu">            <span id="hide"></span>            <span id="show"></span>        </div>        <ul id="list">            <li>                <a href="#">首页</a>            </li>            <li>                <a href="#">问题</a>            </li>            <li>                <a href="#">文章</a>            </li>            <li>                <a href="#">关注</a>            </li>            <li>                <a href="#">发现</a>            </li>        </ul>    </nav>

nav{ width: 100%; height: 50px; background-color: rgba(26,188, 156, 0.75); position: relative; }        div{ position: absolute; height: 100%; width: 50px; left: 20px; cursor: pointer; -webkit-transition: transform 1s; -moz-transition: transform 1s; -ms-transition: transform 1s; -o-transition: transform 1s; transition: transform 1s; }        #hide,#show{ display: block; height: 3px; background-color: #FFF; position: absolute; top: 50%; -webkit-transition: opacity .5s; -moz-transition: opacity .5s; -ms-transition: opacity .5s; -o-transition: opacity .5s; transition: opacity .5s; }        #show{ width: 20px; left: 15px; opacity: 0; }        #hide{ width: 30px; left: 10px; margin-top: -1.5px; }        #hide::before,#hide::after,#show::before,#show::after{ content: ""; display: block; height: 3px; background-color: #FFF; position: absolute; }        #hide::before,#hide::after{ width: 30px; }        #show::before,#show::after{ width: 25px; }        #hide::before,#show::before{ top: -10px; }        #hide::after,#show::after{ top: 10px; }        #show::before{ -webkit-transform: rotate(35deg) translateX(5px); -moz-transform: rotate(35deg) translateX(5px); -ms-transform: rotate(35deg) translateX(5px); -o-transform: rotate(35deg) translateX(5px); transform: rotate(35deg) translateX(5px); }        #show::after{ -webkit-transform: rotate(-35deg) translateX(5px); -moz-transform: rotate(-35deg) translateX(5px); -ms-transform: rotate(-35deg) translateX(5px); -o-transform: rotate(-35deg) translateX(5px); transform: rotate(-35deg) translateX(5px); }        ul{ list-style: none; background-color: #455552; position: absolute; top: 34px; left: -200px; width: 74px; -webkit-transition: all .5s ease-in-out; -moz-transition: all .5s ease-in-out; -ms-transition: all .5s ease-in-out; -o-transition: all .5s ease-in-out; transition: all .5s ease-in-out; }        li{ margin: 0; padding: 0; position: relative; left: -40px; text-align: center; width: 112px; }        a{ text-decoration: none; color:#FFF; display: inline-block; height: 40px; line-height: 40px; }        li:hover{ background-color: rgba(26,188, 156, 0.75); }

var toggle = document.getElementById("toggleMenu");        var list = document.getElementById("list");        var hide = document.getElementById("hide");        var show = document.getElementById("show");        var isHidden = true;        window.onload = function() {            toggle.onclick=function(){                if(isHidden){                    list.style.left="0px";                    isHidden = false;                    hide.style.opacity=0;                    this.style.mozTransform = "rotate(180deg)";                    this.style.msTransform = "rotate(180deg)";                    this.style.oTransform = "rotate(180deg)";                    this.style.webkitTransform = "rotate(180deg)";                    this.style.transform = "rotate(180deg)";                    show.style.opacity=1;                }else{                    list.style.left="-200px";                    isHidden = true;                    hide.style.opacity=1;                    this.style.mozTransform = "rotate(0deg)";                    this.style.msTransform = "rotate(0deg)";                    this.style.oTransform = "rotate(0deg)";                    this.style.webkitTransform = "rotate(0deg)";                    this.style.transform = "rotate(0deg)";                    show.style.opacity=0;                }            }        }