纯CSS制作的下拉导航菜单-这是一个老外的作品，基本上全是用CSS+HTML写出来的，值得大家学习

以下是引用片段：
<style type="text/css">
.menu {
font-family: verdana, sans-serif;
width:750px;
position:relative;
font-size:0.85em;
padding-bottom:250px;
}
.menu ul {
padding:0;
margin:0;
list-style-type: none;
}
.menu ul li {
float:left;
position:relative;
}
.menu ul li a, .menu ul li a:visited {
display:block;
text-decoration:none;
color:#000;
width:139px;
height:3em;
color:#000;
border:1px solid #fff;
border-width:1px 1px 0 0;
background:#dfc184;
padding-left:10px;
line-height:3em;
}
* html .menu ul li a, .menu ul li a:visited {
width:149px;
w\idth:139px;
}
.menu ul li ul {
display: none;
}
table {
margin:-1px;
border-collapse:collapse;
font-size:1em;
}

/* specific to non IE browsers */
.menu ul li:hover a {
color:#fff;
background:#bd8d5e;
}
.menu ul li:hover ul {
display:block;
position:absolute;
top:3em;
margin-top:1px;
left:0;
width:150px;
}
.menu ul li:hover ul li ul {
display: none;
}
.menu ul li:hover ul li a {
display:block;
background:#faeec7;
color:#000;
height:auto;
line-height:1.2em;
padding:5px 10px;
width:129px
}
.menu ul li:hover ul li a.drop {
background:#c9c9a7 url(../../graphics/drop.gif) bottom right no-repeat;
}
.menu ul li:hover ul li a:hover {
background:#c9c9a7;
color:#000;
}
.menu ul li:hover ul li:hover ul {
display:block;
position:absolute;
left:150px;
top:0;
width:150px;
}
.menu ul li:hover ul li:hover ul.left {
left:-150px;
}

</style>
<!--[if lte IE 6]>
<style type="text/css">
.menu ul li a:hover {
color:#fff;
background:#bd8d5e;
}
.menu ul li a:hover ul {
display:block;
position:absolute;
top:3em;
left:0;
background:#fff;
margin-top:0;
marg\in-top:1px;
}
.menu ul li a:hover ul li a {
display:block;
background:#dbe4ab;
color:#000;
height:auto;
line-height:1.5em;
padding:5px 10px;
width:150px;
w\idth:129px;
}
.menu ul li a:hover ul li a.drop {
background:#c9c9a7 url(../../graphics/drop.gif) bottom right no-repeat;
}
.menu ul li a:hover ul li a ul {
visibility:hidden;
position:absolute;
height:0;
width:0;
}
.menu ul li a:hover ul li a:hover {
background:#c9c9a7; color:#000;
}
.menu ul li a:hover ul li a:hover ul {
visibility:visible;
position:absolute;
top:0;
color:#000;
left:150px;
}
.menu ul li a:hover ul li a:hover ul.left {
left:-150px;
}

</style>
<![endif]-->
<div class="menu">

<ul>
<li><a class="drop" href="../menu/index.html">DEMOS
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

    <ul>
    <li><a href="../menu/zero_dollars.html" title="The zero dollar ads page">zero dollars advertising page</a></li>
    <li><a href="../menu/embed.html" title="Wrapping text around images">wrapping text around images</a></li>
    <li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
    <li><a href="../menu/nodots.html" title="Removing active/focus borders">active focus</a></li>

    <li><a class="drop" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">hover/click with no borders
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->


<table><tr><td>
        <ul>
            <li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
            <li><a href="../menu/nodots.html" title="Removing active/focus borders">removing active/focus borders</a></li>
            <li><a href="../menu/hover_click.html" title="Hover/click with no active/focus borders">hover/click</a></li>
        </ul>
</td></tr></table>

<!--[if lte IE 6]>
</a>
<![endif]-->

    </li>

    <li class="upone"><a href="../menu/shadow_boxing.html" title="Multi-position drop shadow">shadow boxing</a></li>
    <li><a href="../menu/old_master.html" title="Image Map for detailed information">image map for detailed information</a></li>
    <li><a href="../menu/bodies.html" title="fun with background images">fun with background images</a></li>
    <li><a href="../menu/fade_scroll.html" title="fade-out scrolling">fade scrolling</a></li>
    <li><a href="../menu/em_images.html" title="em size images compared">em image sizes compared</a></li>
    </ul>

</td></tr></table>

<!--[if lte IE 6]>
</a>
<![endif]-->

</li>


<li><a href="../boxes/index.html">BOXES
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->


<table><tr><td>

    <ul>
    <li><a href="spies.html" title="a coded list of spies">a coded list of spies</a></li>
    <li><a href="vertical.html" title="a horizontal vertical menu">vertical menu</a></li>
    <li><a href="expand.html" title="an enlarging unordered list">enlarging unordered list</a></li>
    <li><a href="enlarge.html" title="an unordered list with link images">link images</a></li>
    <li><a href="cross.html" title="non-rectangular links">non-rectangular</a></li>
    <li><a href="jigsaw.html" title="jigsaw links">jigsaw links</a></li>
    <li><a href="circles.html" title="circular links">circular links</a></li>
    </ul>

</td></tr></table>

<!--[if lte IE 6]>
</a>
<![endif]-->

</li>

<li><a href="../mozilla/index.html">MOZILLA
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->


<table><tr><td>

    <ul>
    <li><a href="../mozilla/dropdown.html" title="A drop down menu">drop down menu</a></li>
    <li><a href="../mozilla/cascade.html" title="A cascading menu">cascading menu</a></li>
    <li><a href="../mozilla/content.html" title="Using content:">content:</a></li>
    <li><a href="../mo