钢琴音阶导航

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    *{
        padding: 0;
        margin: 0;
    }
    html,body{
        height: 100%;
        overflow: hidden;
    }

    ul{
        margin: 300px auto;
        width:909px;
        height: 38px;
        background: pink;
        list-style: none;
        border: 1px solid;
        overflow: hidden;
    }
    a{
        text-decoration: none;
        display: block;
        color: black;
    }
    ul li{
        float: left;
        height: 100%;
        width: 100px;
        text-align: center;
        line-height: 38px;
    }
    ul li:not(:last-child){
        border-right: 1px solid;
    }
    ul li div.down{
        width: 100%;
        height: 100%;
        background: aqua;
        transition: .7s;
    }
    ul li:hover .down{
        transform:translateY(-38px);
    }


</style>
<script>

</script>
<body>
<div id="wrap">
    <ul class="nav">
        <li flag="a">
            <a href="#">我的首页</a>
            <div class="down"></div>
         </li>
        <li flag="b">
            <a href="#">你的首页</a>
            <div class="down"></div>
        </li>
        <li flag="c">
            <a href="#">他的首页</a>
            <div class="down"></div>
        </li>
        <li flag="d">
            <a href="#">她的首页</a>
            <div class="down"></div>
        </li>
        <li flag="e">
            <a href="#">它的首页</a>
            <div class="down"></div>
        </li>
        <li flag="f">
            <a href="#">不知道的</a>
            <div class="down"></div>
        </li>
        <li flag="g">
            <a href="#">你猜猜是</a>
            <div class="down"></div>
        </li>
        <li flag="h">
            <a href="#">不告诉你</a>
            <div class="down"></div>
        </li>
        <li flag="i">
            <a href="#">不告诉她</a>
            <div class="down"></div>
        </li>
    </ul>
    <audio></audio>

</div>
<script type="text/javascript">
    var liNode=document.querySelectorAll(".nav>li");
    var audio=document.querySelector("audio");
    for (var i=0;i<liNode.length;i++){
        liNode[i].addEventListener("mouseenter",function () {
            var flag=this.getAttribute("flag")
            if (flag){
                audio.src="http://s8.qhimg.com/share/audio/piano1/"+flag+"4.mp3";
                audio.play();
            }
        })
    }
</script>
</body>
</html>

钢琴音阶导航