麻烦帮我看一下为什么在浏览器点击按钮后变不了two的样式
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>innerHTML</title>
<style>
input{
font-size:10px;
}
.one{
width:500px;
background-color:red;
.two{
font-size:200px;
color:blue;
}
</style>
<body>
<h1>JAVASCRIPT</h1>
<p id="con" class="one">作为一个优秀的PHP开发师</p>
<form>
<input type="button" value="改变类样式" onclick="myClass()">
</form>
<script type="text/javascript">
var mychar=document.getElementById("con")
document.write("p元素的class值为:"+mychar.className+"<br>");
function myClass(){
mychar.className="two";
}
</script>
</body>
</html>