用js实现手机导航-优化版

<header>
<div id="mnav">
   <div class="logo"><a href="/">杨青个人博客</a></div>
    <h2 id="mnavh"><span class="navicon"></span></h2>
    <ul id="starlist">
      <li><a href="/">网站首页</a></li>
      <li><a href="/">关于我</a></li>
      <li><a href="/">模板分享</a></li>
      <li><a href="/">学无止境</a></li>
      <li><a href="/">慢生活</a></li>
      <li><a href="/">博客导航</a></li>
      <li><a href="/">留言</a></li>
    </ul>
</div>
<script>
window.onload = function ()
{
    var oH2 = document.getElementById("mnavh"); 
    var oUl = document.getElementById("starlist");  
    oH2.onclick = function ()
    {
        var style = oUl.style;
        style.display = style.display == "block" ? "none" : "block";
        oH2.className = style.display == "block" ? "open" : ""
    }
}
</script>
</header>

/* header */

header{ width:100%; color:#FFF; background:#333; line-height:40px; overflow:hidden; position:fixed; top:0; z-index:100}
.logo{ float:left; font-size:22px}
#mnav {width:1200px; margin:auto }
#mnav a{ color:#FFF}
#mnavh{ display:none;width:30px; height:40px; float:right; text-align:center; padding:0 5px}
#starlist{ float:right;  }
#starlist li{ float:left; display:inline-block; padding: 0 0 0 40px; font-size:16px}
.navicon { display: block; position: relative; width: 30px; height: 5px; background-color: #FFFFFF; margin-top:18px }
.navicon:before, .navicon:after { content: ''; display: block; width: 30px; height: 5px; position: absolute; background: #FFFFFF; -webkit-transition-property: margin, -webkit-transform; transition-property: margin, -webkit-transform; transition-property: margin, transform; transition-property: margin, transform, -webkit-transform; -webkit-transition-duration: 300ms; transition-duration: 300ms; }
.navicon:before { margin-top: -10px; }
.navicon:after { margin-top: 10px; }
.open .navicon { background:none }
.open .navicon:before { margin-top: 0; -webkit-transform: rotate(45deg); transform: rotate(45deg); }
.open .navicon:after { margin-top: 0; -webkit-transform: rotate(-45deg); transform: rotate(-45deg); }
.open .navicon:before, .open .navicon:after { content: ''; display: block; width: 30px; height: 5px; position: absolute; background: #FFFFFF;  }


/* for 768px or less */
@media screen and (max-width: 768px) {
#mnav { width: 100%; overflow: hidden }
#mnavh { display: block; }
#starlist { display: none; width: 100%; }
#starlist li { float: none; display: block; padding: 0 0 0 0; width: 100%; text-align: center }
}