请问一下我的nav盒子为什么不能一起随着logo盒子浮动啊

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>作业2</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
        <div class="header w">
            <div class="logo">
                 <img src="千库.png" alt="">
            </div>
            </div>
            <div class="nav">
                <ul>
                    <li><a href="#">网站首页</a></li>
                    <li><a href="#">关于我们</a></li>
                    <li><a href="#">新闻中心</a></li>
                    <li><a href="#">产品中心</a></li>
                    <li><a href="#">联系我们</a></li>
                </ul>
            </div>
        </div>
</body>
</html>
```css

* {
    margin: 0;
    padding: 0;
}
.w {
    width: 1215px;
    margin: auto;
}
body {
    background-color:transparent;
}
li {
    list-style: none;
}
a {
    text-decoration: none;
}
.clearfix:before,.clearfix:after {
    content:"";
    display:table; 
}
.clearfix:after {
    clear:both;
}
.clearfix {
     *zoom:1;
}
.header{
    height: 90px;
    margin: 23px auto;
}
.logo{
    float:left;
    width: 47px;
    height: 90px;
}
.nav{
    float:left;
    margin-left: 404px;
}
.nav ul li{
    float:left;
    margin: 0 45px;
}
.nav ul li a {
    display: block;
    height: 90px;
    padding: 0px;
    line-height: 90px;
    font-size: 18px;
    color: blue;   
}
.nav ul li a:hover {
    border-bottom: 2px solid #ff812a;
    color: #ff812a;
}