老师，我的导航栏背景颜色怎么显示不出来

来源：2-2 编程练习

李李明明

2020-04-10 17:04:17

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>IMOOC</title>
<style>
*{
padding: 0;
margin: 0;

}
a{
text-decoration: none;
}
header{
height: 50px;
background-color: black;
overflow: hidden;
}
header >.container{
width: 1000px;
margin: 0 auto;
overflow: hidden;
}
header >.container >a{
height: 40px;
width: 40px;
display: block;
float: left;
margin: 5px 25px;
}
header >.container >span{
color: white;
line-height: 50px;
height: 50px;
padding-left: 5px;

}
/* header.container nav{
overflow: hidden;
}*/

header .container nav {
float: right;
display: block;
height: 50px;
line-height: 50px;

}
header .container nav a{
color: white;
padding:20px ;
}
header .container nav a .Home{background:#433b90;}
header .container nav a .Course{background:#017fcb;}
header .container nav a .Actual{background:#78b917;}
header .container nav a .Plan{background:#feb800;}
header .container nav a .FAQ{background:#f27c01;}
header .container nav a .Notes{background:#d40;}
header .container nav :hover,:active{
padding-bottom: 2px;
}

</style>
</head>
<body>

<header>
<div class="container">
<a><img src="http://climg.mukewang.com/582e5f160001b17100400040.png"></a>
<span>MYMOOC</span>
<nav>
<a class="Home" href="#">Home</a>
<a class="Course" href="#">Course</a>
<a class="Actual" href="#">Actual</a>
<a class="Plan" href="#">Plan</a>
<a class="FAQ" href="#">FAQ</a>
<a class="Notes" href="#">Notes</a>
</nav>
</div>
</header>
</body>
</html>