完全CSS下拉菜单，只用CSS，纯CSS构筑！

看CSS代码，要注意认真看，好好研究哦！

 Example Source Code [www.52css.com]

<style type="text/css">
.menu {
font-family: verdana, sans-serif; 
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; 
139px; 
height:3em; 
color:#000; 
border:1px solid #fff; 
border-1px 1px 0 0; 
background:#dfc184; 
padding-left:10px; 
line-height:3em;
}
* html .menu ul li a, .menu ul li a:visited {
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; 
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; 
129px
}
.menu ul li:hover ul li a.drop {
background:#c9c9a7;
}
.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;
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; 
150px;
w\idth:129px;
}
.menu ul li a:hover ul li a.drop {
background:#c9c9a7;
}
.menu ul li a:hover ul li a ul {
visibility:hidden; 
position:absolute; 
height:0; 
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]-->

下面再看看XHTML代码，同样要认真理解。

 Example Source Code [www.52css.com]

<div class="menu">
<ul>
<li><a class="drop" href="http://www.52css.com/">DEMOS
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->
<table><tr><td>
    <ul>
    <li><a href="http://www.52css.com/" title="The zero dollar ads page">zero dollars advertising page</a></li>
    <li><a href="http://www.52css.com/" title="Wrapping text around images">wrapping text around images</a></li>
    <li><a href="http://www.52css.com/" title="Styling forms">styled form</a></li>
    <li><a href="http://www.52css.com/" title="Removing active/focus borders">active focus</a></li>
    <li><a class="drop" href="http://www.52css.com/" 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="http://www.52css.com/" title="Styling forms">styled form</a></li>
            <li><a href="http://www.52css.com/" title="Removing active/focus borders">removing active/focus borders</a></li>
            <li><a href="http://www.52css.com/" 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="http://www.52css.com/" title="Multi-position drop shadow">shadow boxing</a></li>
    <li><a href="http://www.52css.com/" title="Image Map for detailed information">image map for detailed information</a></li>
    <li><a href="http://www.52css.com/" title="fun with background images">fun with background images</a></li>
    <li><a href="http://www.52css.com/" title="fade-out scrolling">fade scrolling</a></li>
    <li><a href="http://www.52css.com/" 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="http://www.52css.com/">BOXES
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->
<table><tr><td>
    <ul>
    <li><a href="http://www.52css.com/" title="a coded list of spies">a coded list of spies</a></li>
    <li><a href="http://www.52css.com/" title="a horizontal vertical menu">vertical menu</a></li>
    <li><a href="http://www.52css.com/" title="an enlarging unordered list">enlarging unordered list</a></li>
    <li><a href="http://www.52css.com/" title="an unordered list with link images">link images</a></li>
    <li><a href="http://www.52css.com/" title="non-rectangular links">non-rectangular</a></li>
    <li><a href="http://www.52css.com/" title="jigsaw links">jigsaw links</a></li>
    <li><a href="http://www.52css.com/" title="circular links">circular links</a></li>
    </ul>
</td></tr></table>
<!--[if lte IE 6]>
</a>
<![endif]-->
</li>
<li><a href="http://www.52css.com/">MOZILLA
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->
<table><tr><td>
    <ul>
    <li><a href="http://www.52css.com/" title="A drop down menu">drop down menu</a></li>
    <li><a href="http://www.52css.com/" title="A cascading menu">cascading menu</a></li>
    <li><a href="http://www.52css.com/" title="Using content:">content:</a></li>
    <li><a href="http://www.52css.com/" title=":hover applied to a div">mozzie box</a></li>
    <li><a href="http://www.52css.com/" title="I can build a rainbow">I can build a rainbow with transparent borders</a></li>
    <li><a href="http://www.52css.com/" title="Snooker cue">a snooker cue using border art</a></li>
    <li><a href="http://www.52css.com/" title="Target Practise">target practise</a></li>
    <li><a href="http://www.52css.com/" title="Two tone headings">two tone headings</a></li>
    <li><a href="http://www.52css.com/" title="Shadow text">shadow text</a></li>
    </ul>
</td></tr></table>
<!--[if lte IE 6]>
</a>
<![endif]-->
</li>
<li><a href="http://www.52css.com/">EXPLORER
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->
<table><tr><td>
    <ul>
    <li><a href="http://www.52css.com/" title="Example one">the first example for Internet Explorer</a></li>
    <li><a href="http://www.52css.com/" title="Weft fonts">weft fonts</a></li>
    <li><a href="http://www.52css.com/" title="Vertical align">vertically aligning text</a></li>
    </ul>
</td></tr></table>
<!--[if lte IE 6]>
</a>
<![endif]-->
</li>
<li><a href="http://www.52css.com/">OPACITY
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->
<table><tr><td>
    <ul>
    <li><a href="http://www.52css.com/" title="colour wheel">a colour wheel using opaque colours</a></li>
    <li><a href="http://www.52css.com/" title="a menu using opacity">a menu using opacity</a></li>
    <li><a href="http://www.52css.com/" title="partial opacity">partial opacity</a></li>
    <li><a href="http://www.52css.com/" title="partial opacity II">partial opacity II</a></li>
    <li><a class="drop" href="http://www.52css.com/" title="Hover/click with no active/focus borders">HOVER/CLICK
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->
<table><tr><td>
        <ul class="left">
            <li><a href="http://www.52css.com/" title="Styling forms">styled form</a></li>
            <li><a href="http://www.52css.com/" title="Removing active/focus borders">removing active/focus borders</a></li>
            <li><a href="http://www.52css.com/" title="Hover/click with no active/focus borders">hover/click</a></li>
        </ul>
</td></tr></table>
<!--[if lte IE 6]>
</a>
<![endif]-->

    </li>
    </ul>
</td></tr></table>
<!--[if lte IE 6]>
</a>
<![endif]-->
</li>
</ul>
</div>

 

Source Code to Run 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>52css.com</title>
<style type="text/css">
.menu {
font-family: verdana, sans-serif;
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;
139px;
height:3em;
color:#000;
border:1px solid #fff;
border-1px 1px 0 0;
background:#dfc184;
padding-left:10px;
line-height:3em;
}
* html .menu ul li a, .menu ul li a:visited {
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;
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;
129px
}
.menu ul li:hover ul li a.drop {
background:#c9c9a7;
}
.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;
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;
150px;
w\idth:129px;
}
.menu ul li a:hover ul li a.drop {
background:#c9c9a7;
}
.menu ul li a:hover ul li a ul {
visibility:hidden;
position:absolute;
height:0;
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]-->
</head>
<body>
<div class="menu">

<ul>
<li><a class="drop" href="http://www.52css.com/">DEMOS
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

    <ul>
    <li><a href="http://www.52css.com/" title="The zero dollar ads page">zero dollars advertising page</a></li>
    <li><a href="http://www.52css.com/" title="Wrapping text around images">wrapping text around images</a></li>
    <li><a href="http://www.52css.com/" title="Styling forms">styled form</a></li>
    <li><a href="http://www.52css.com/" title="Removing active/focus borders">active focus</a></li>
    <li><a class="drop" href="http://www.52css.com/" 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="http://www.52css.com/" title="Styling forms">styled form</a></li>
            <li><a href="http://www.52css.com/" title="Removing active/focus borders">removing active/focus borders</a></li>
            <li><a href="http://www.52css.com/" 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="http://www.52css.com/" title="Multi-position drop shadow">shadow boxing</a></li>
    <li><a href="http://www.52css.com/" title="Image Map for detailed information">image map for detailed information</a></li>
    <li><a href="http://www.52css.com/" title="fun with background images">fun with background images</a></li>
    <li><a href="http://www.52css.com/" title="fade-out scrolling">fade scrolling</a></li>
    <li><a href="http://www.52css.com/" 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="http://www.52css.com/">BOXES
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

    <ul>
    <li><a href="http://www.52css.com/" title="a coded list of spies">a coded list of spies</a></li>
    <li><a href="http://www.52css.com/" title="a horizontal vertical menu">vertical menu</a></li>
    <li><a href="http://www.52css.com/" title="an enlarging unordered list">enlarging unordered list</a></li>
    <li><a href="http://www.52css.com/" title="an unordered list with link images">link images</a></li>
    <li><a href="http://www.52css.com/" title="non-rectangular links">non-rectangular</a></li>
    <li><a href="http://www.52css.com/" title="jigsaw links">jigsaw links</a></li>
    <li><a href="http://www.52css.com/" title="circular links">circular links</a></li>
    </ul>

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

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

</li>

<li><a href="http://www.52css.com/">MOZILLA
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

    <ul>
    <li><a href="http://www.52css.com/" title="A drop down menu">drop down menu</a></li>
    <li><a href="http://www.52css.com/" title="A cascading menu">cascading menu</a></li>
    <li><a href="http://www.52css.com/" title="Using content:">content:</a></li>
    <li><a href="http://www.52css.com/" title=":hover applied to a div">mozzie box</a></li>
    <li><a href="http://www.52css.com/" title="I can build a rainbow">I can build a rainbow with transparent borders</a></li>
    <li><a href="http://www.52css.com/" title="Snooker cue">a snooker cue using border art</a></li>
    <li><a href="http://www.52css.com/" title="Target Practise">target practise</a></li>
    <li><a href="http://www.52css.com/" title="Two tone headings">two tone headings</a></li>
    <li><a href="http://www.52css.com/" title="Shadow text">shadow text</a></li>
    </ul>

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

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

</li>

<li><a href="http://www.52css.com/">EXPLORER
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

    <ul>
    <li><a href="http://www.52css.com/" title="Example one">the first example for Internet Explorer</a></li>
    <li><a href="http://www.52css.com/" title="Weft fonts">weft fonts</a></li>
    <li><a href="http://www.52css.com/" title="Vertical align">vertically aligning text</a></li>
    </ul>

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

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

</li>

<li><a href="http://www.52css.com/">OPACITY
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

    <ul>
    <li><a href="http://www.52css.com/" title="colour wheel">a colour wheel using opaque colours</a></li>
    <li><a href="http://www.52css.com/" title="a menu using opacity">a menu using opacity</a></li>
    <li><a href="http://www.52css.com/" title="partial opacity">partial opacity</a></li>
    <li><a href="http://www.52css.com/" title="partial opacity II">partial opacity II</a></li>

    <li><a class="drop" href="http://www.52css.com/" title="Hover/click with no active/focus borders">HOVER/CLICK
<!--[if IE 7]><!-->
</a>
<!--<![endif]-->

<table><tr><td>

        <ul class="left">
            <li><a href="http://www.52css.com/" title="Styling forms">styled form</a></li>
            <li><a href="http://www.52css.com/" title="Removing active/focus borders">removing active/focus borders</a></li>
            <li><a href="http://www.52css.com/" title="Hover/click with no active/focus borders">hover/click</a></li>
        </ul>

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

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

    </li>
    </ul>

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

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

</li>
</ul>

</div>
</body>
</html>

查看最后完成的效果！纯CSS构筑的下拉导航菜单！