这次给大家带来css实现大型下拉菜单步骤详解，css实现大型下拉菜单的注意事项有哪些，下面就是实战案例，一起来看一下。
这是一款纯css实现的大型下拉菜单。该大型菜单使用html和纯css代码制作，没有任何js代码，不依赖任意第三方插件。适合用于栏目分类较多的大型网站使用。
html结构
该大型菜单的html结构如下：
<nav>
<ul class="container ul-reset">
<li><a href='#'>home</a></li>
<li class='droppable'>
<a href='#'>category one</a>
<p class='mega-menu'>
<p class="container cf">
<ul class="ul-reset">
<h3>heading 1</h3>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
</ul><!-- .ul-reset -->
<ul class="ul-reset">
<h3>heading 2</h3>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
</ul><!-- .ul-reset -->
<ul class="ul-reset">
<h3>heading 3</h3>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
<li><a href='#'>category one sublink</a></li>
</ul><!-- .ul-reset -->
<ul class="ul-reset">
<h3>heading 4</h3>
<li><img src="http://placehold.it/205x172"></li>
</ul>
</p><!-- .container -->
</p><!-- .mega-menu -->
</li><!-- .droppable -->
<li class='droppable'>
<a href='#'>category two</a>
<p class='mega-menu'>
<p class="container cf">
<ul class="ul-reset">
<h3>heading 1</h3>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
</ul><!-- .ul-reset -->
<ul class="ul-reset">
<h3>heading 2</h3>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
</ul><!-- .ul-reset -->
<ul class="ul-reset">
<h3>heading 3</h3>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
</ul><!-- .ul-reset -->
<ul class="ul-reset">
<h3>heading 4</h3>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
<li><a href='#'>category two sublink</a></li>
</ul><!-- .ul-reset -->
</p><!-- .container -->
</p><!-- .mega-menu-->
</li><!-- .droppable -->
<li><a href='#'>category three</a></li>
<li><a href='#'>category four</a></li>
<li><a href='#'>category five</a></li>
<li><a href='#'>category six</a></li>
</ul><!-- .container .ul-reset -->
</nav>
css
为该大型菜单添加下面的css样式：
/* #resets
–––––––––––––––––––––––––––––––––––––––––––––––––– */
html {box-sizing: border-box;}
*, *:before, *:after {box-sizing: inherit; }
/* #universal and default styles
–––––––––––––––––––––––––––––––––––––––––––––––––– */
body {
background: url(../img/black-wood-small.jpg);
color: #ddd;
font-family: open sans, sans-serif;
font-size: 14px;
line-height: 1;
margin: 0;
padding: 0;
text-align: center;
}
a {text-decoration: none;}
h1 {
font-size: 40px;
font-weight: 700;
margin-bottom: 20px;
margin-top: 20px;
}
h2 {
font-size: 15px;
font-weight: 600;
margin-bottom: 30px;
margin-top: 10px;
}
.container {
margin: auto;
width: 940px;
}
.ul-reset {
padding-left: 0;
margin-top: 0;
margin-bottom: 0;
list-style: none;
}
/* #navigation styles
–––––––––––––––––––––––––––––––––––––––––––––––––– */
nav {
background: #424242;
font-size: 0;
position: relative;
}
nav > ul > li {
display: inline-block;
font-size: 14px;
padding: 0 15px;
position: relative;
}
nav > ul > li:first-child {padding-left: 0;}
nav > ul > li:last-child {padding-right: 0;}
nav > ul > li > a {
color: #fff;
display: block;
position: relative;
padding: 20px 0;
border-bottom: 3px solid transparent;
}
nav > ul > li:hover > a {
color: #69aae0;
border-bottom: 3px solid #69aae0;
}
/* #mega menu styles
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.mega-menu {
background: #f0f0f0;
display: none;
left: 0;
position: absolute;
text-align: left;
width: 100%;
}
.mega-menu h3 {color: #444;}
.mega-menu ul {
float: left;
margin-bottom: 20px;
margin-right: 40px;
width: 205px;
}
.mega-menu ul:last-child {margin-right: 0;}
.mega-menu a {
border-bottom: 1px solid #ddd;
color: #4ea3d8;
display: block;
padding: 10px 0;
}
.mega-menu a:hover {color: #2d6a91;}
/* #droppable class styles
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.droppable {position: static;}
.droppable > a:after {
content: \f107;
font-family: fontawesome;
font-size: 12px;
padding-left: 6px;
position: relative;
top: -1px;
}
.droppable:hover .mega-menu {display: block;}
/* #browser clearfix
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.cf:before,
.cf:after {
content: ; /* 1 */
display: table; /* 2 */
}
.cf:after {clear: both;}
相信看了本文案例你已经掌握了方法，更多精彩请关注其它相关文章！
推荐阅读：
vue.js开发mpvue框架步骤详解
jquery fullpage插件添加头部与尾部版权相关
以上就是css实现大型下拉菜单步骤详解的详细内容。