纯CSD实现的大型下拉菜单的示例代码有哪些？

<nav>
 <ul class="container ul-reset">
  <li><a href='#'>Home</a></li>
  <li class='droppable'>
   <a href='#'>Category One</a>
   <div class='mega-menu'>
    <div 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>
    </div><!-- .container -->
   </div><!-- .mega-menu -->
  </li><!-- .droppable -->
  <li class='droppable'>
   <a href='#'>Category Two</a>
   <div class='mega-menu'>
    <div 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 -->
    </div><!-- .container -->
   </div><!-- .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>

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–––––––––––––––––––––––––––––––––––––––––––––––––– */
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*, *: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;
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}
nav > ul > li:hover > a {
 color: #69aae0; 
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}
/* #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 {
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  margin-bottom: 20px;
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  width: 205px;
}
.mega-menu ul:last-child {margin-right: 0;}
.mega-menu a {
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  display: block;
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}
.mega-menu a:hover {color: #2d6a91;}
/* #Droppable Class Styles
–––––––––––––––––––––––––––––––––––––––––––––––––– */
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.droppable > a:after {
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.droppable:hover .mega-menu {display: block;}
/* #Browser Clearfix
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.cf:before,
.cf:after {
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.cf:after {clear: both;}