Secondary Navigation bar production:
1. The removal of a navigation bar pattern list (list-style: none), and given floating, so that the transverse arrangement (float: left)
2. Add to each one <a> </a> label li, to a set pattern, making block-level elements (display: block), so that only one click li current range of the region to trigger a jump
3. to add li two required navigation bar which added ul> li, to a class name, set its style to (display: none), so hidden in ordinary circumstances
4. Set a navigation bar across the effect, when the slide has two navigation bar li, provided two navigation bar state (display: block), the display state is the
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<!-- <link rel="stylesheet" href="./../common/common.css"> -->
<title>Document</title>
<style>
*{
margin: 0;
padding: 0;
}
ul,li{
list-style: none;
}
.one{
width: 600px;
background-color: coral;
height: 30px;
margin: 0 auto;
}
.one li{
float: left;
width: 100px;
text-align: center;
line-height: 30px;
}
.one li:hover{
background-color: #fff;
color: coral;
}
.one .two{
display: none;
}
.one li:hover .two{
display: block;
}
.one .two li{
background-color: cadetblue;
}
.one .two li:hover{
background-color: honeydew;
}
a{
display: block;
text-decoration: none;
}
</style>
</head>
<body>
<ul class="one">
<li><a href="">一级</a> </li>
<li><a href="">一级</a> </li>
<li><a href="">一级</a>
<ul class="two">
<li><a href="">二级</a> </li>
<li><a href="">二级</a> </li>
<li><a href="">二级</a> </li>
</ul>
</li>
<li><a href="">一级</a> </li>
<li><a href="">一级</a> </li>
<li><a href="">一级</a> </li>
</ul>
</body>
</html>