我的 CSS 菜单有这个 html:
<nav class="clearfix">
<ul class="clearix">
<li><a href="http://www.domain.co.uk/">Homepage</a></li>
<li><a href="/services">Services</a></li>
<li><a href="/project-gallery">Project Gallery</a></li>
<li><a href="/contact-us">Contact Us</a></li>
</ul>
<a href="#" id="pull">Menu</a>
</nav>
nav {
height: 50px;
width: 100%;
background: #F00;
font-size: 14pt;
font-family: Arial;
position: relative;
border-bottom: 5px solid #FFFFFF;
}
nav ul {
padding: 0;
margin: 0 auto;
width: 100%;
height: 50px;
text-align: center;
}
nav li {
display: inline;
}
.clearfix:before,
.clearfix:after {
content: " ";
display: table;
}
.clearfix:after {
clear: both;
}
.clearfix {
*zoom: 1;
}
nav a {
color: #FFFFFF;
display: inline-block;
width: auto;
text-align: center;
text-decoration: none;
line-height: 50px;
}
nav li a {
box-sizing:border-box;
-moz-box-sizing:border-box;
-webkit-box-sizing:border-box;
padding-left: 10px;
padding-right: 10px;
}
nav li:last-child a {
border-right: 0;
}
nav a:hover, nav a:active {
background-color: #000000;
color:#FFFFFF;
}
nav a#pull {
display: none;
}
@media screen and (max-width: 600px) {
nav {
height: auto;
}
nav ul {
width: 100%;
display: block;
height: auto;
}
nav li {
width: 50%;
float: left;
position: relative;
}
nav li a {
border-bottom: 1px solid #FFFFFF;
border-right: 1px solid #FFFFFF;
}
nav a {
text-align: left;
width: 100%;
text-indent: 25px;
}
}
@media only screen and (max-width : 480px) {
nav {
border-bottom: 0;
}
nav ul {
display: none;
height: auto;
}
nav a#pull {
display: block;
color:#FFFFFF;
background-color: #F00;
width: 100%;
position: relative;
}
nav a#pull:after {
content:"";
background: url('nav-icon.png') no-repeat;
width: 30px;
height: 30px;
display: inline-block;
position: absolute;
rightright: 15px;
top: 10px;
}
}
@media only screen and (max-width : 320px) {
nav li {
display: block;
float: none;
width: 100%;
}
nav li a {
border-bottom: 1px solid #FFFFFF;
}
}
我正在寻找一种方法来添加子菜单,然后在第一个子菜单上添加第二个子菜单,但仍然保持它的响应速度。
我怎样才能做到这一点?