这很奇怪，我以前从未见过，也许我的电脑需要重新启动，但是：我在网页上添加的每个链接都消失了。你可以在这里看到一个活生生的例子。
这是我的样式表：
/*------- UNIVERSAL -------*/
body
{
background: #333333;
color: #222222;
font-family: Arial, Helvetica, sans-serif;
font-size: 12px;
}
.tleft { text-align: left; }
.tright { text-align: right; }
a
{
text-decoration: none;
color: #e6267c;
font-weight: bold;
}
a :hover{ border-bottom: 1px #e6267c dashed; }
/*------- PAGE PARTS -------*/
#container
{
position: relative;
margin: 0 auto;
width: 760px;
padding: 0 70px 0 70px;
background: url(images/background.png);
}
#top { height: 141px; }
/*------- TOP -------*/
#logo
{
background: url(images/logo.png);
display: block;
width: 263px;
height: 141px;
position: absolute;
top: 0;
left: 50px;
text-indent: -9000px;
}
#addjoke
{
background: url(images/addjoke.png) bottom left;
display: block;
width: 242px;
height: 65px;
position: absolute;
top: 0;
left: 360px;
text-indent: -9000px;
}
#addjoke:hover { height: 95px; }
#quickbar
{
background: url(images/quickbar.png);
width: 160px;
height: 69px;
position: absolute;
top: 0;
left: 670px;
}
#quickbar form, a { display: none; }
/*------- MENU -------*/
#menu
{
color: white;
background: url(images/menumiddle.png) repeat-y;
float: left;
width: 207px;
}
#menu div.box
{
margin-left: 20px;
margin-right: 28px;
}
#menu span.top
{
margin: 0;
display: block;
height: 10px;
background: url(images/menutop.png);
}
#menu span.bottom
{
margin: 0;
display: block;
height: 10px;
background: url(images/menubottom.png);
}
#menu h2
{
margin: 0;
height: 31px;
text-indent: -9000px;
}
#menu ul li
{
padding-left: 15px;
background: url(images/menubullet.png) left 4px no-repeat;
}
/*navigation*/
#navigation { background: url(images/navigation.png); }
/*youraccount*/
#youraccount { background: url(images/youraccount.png); }
img.avatar
{
float: left;
margin-right: 10px;
}
#menu_login { clear: both; margin-top: 20px; margin-bottom: 20px; }
#menu_login input
{
padding: 2px 5px 2px 5px;
color: white;
background: black;
border: 2px solid white;
width: 145px;
}
#menu_login label.label_password { display: block; margin-top: 10px; }
#menu_login div
{
margin-top: 5px;
text-align: right;
}
#menu_login button
{
text-indent: -9000px;
border: 0;
width: 57px;
height: 28px;
background: transparent url(images/loginbutton.png);
cursor: pointer;
cursor: hand;
}
#menu_login label
{
font-weight: bold;
}
/*toprated*/
#toprated { background: url(images/toprated.png); }
/*newsletter*/
#newsletter { background: url(images/newsletter.png); }
/*recentcomments*/
#recentcomments { background: url(images/recentcomments.png); }
/*------- FOOTER -------*/
#footer
{
background: url(images/footer.png);
width: 779px;
height: 57px;
margin: 0 auto;
}
这是我的 XHTML（目前还不完整）：
<!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>
<title>Conforming XHTML 1.0 Strict Template</title>
<meta name="description" content="" />
<meta name="keywords" content="" />
<meta name="author" content="" />
<meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1" />
<link rel="stylesheet" type="text/css" href="http://yui.yahooapis.com/2.7.0/build/reset/reset-min.css" />
<link rel="stylesheet" type="text/css" href="stylesheet.css" />
</head>
<body>
<div id="container">
<div id="top">
<a id="logo" href="http://superfunnyjokes.net/">SuperFunnyJokes.Net</a>
<a id="addjoke">Add Joke</a>
<div id="quickbar">
<form action="http://superfunnyjokes.net/search/" method="post">
<input type="text" name="query" />
<input type="submit" value="Search" />
</form>
<a href="http://superfunnyjokes.net/rss/">RSS Feed</a>
</div>
</div>
<div id="menu">
<!-- span for top of menu, replace with jquery -->
<span class="top"></span>
<h2 id="navigation">Navigation</h2>
<div class="box">
<ul>
<li><a href="http://superfunnyjokes.net/">Home</a></li>
<li><a href="http://superfunnyjokes.net/categories/">Joke Categories</a></li>
<li><a href="http://superfunnyjokes.net/random/">Random Joke</a></li>
<li><a href="http://superfunnyjokes.net/members/registration/">Become A Member</a></li>
<li><a href="http://superfunnyjokes.net/add/">Add A Joke</a></li>
</ul>
</div>
<h2 id="youraccount">Your Account</h2>
<div class="box">
<img class="avatar" src="images/noavatar.png" />
<p>Welcome back! You are not signed in.</p>
<form id="menu_login" action="http://superfunnyjokes.net/members/login.php" method="post">
<label for="menu_username">Username:</label>
<input id="menu_username" type="text" name="username" />
<label class="label_password" for="menu_password">Password:</label>
<input id="menu_password" type="password" name="password" />
<div><button type="submit">Login</button></div>
</form>
</div>
<h2 id="toprated">Top Rated Jokes</h2>
<div class="box">
<ul class="ordered">
<li><a>The Werewolf and Me</a></li>
<li><a>Erection</a></li>
<li><a>The Werewolf and Me</a></li>
<li><a>Erection</a></li>
<li><a>The Werewolf and Me</a></li>
</ul>
</div>
<h2 id="newsletter">Newsletter</h2>
<div class="box">
<form id="menu_newsletter" action="http://superfunnyjokes.com/newsletter/register.php" method="post">
<table>
<tr>
<td><label for="menu_email">Email:</label></td>
<td><input id="menu_email" type="text" name="email" /></td>
</tr>
<tr>
<td></td>
<td><button type="submit">Sign Up</button></td>
</tr>
</table>
</form>
</div>
<h2 id="recentcomments">Recent Comments</h2>
<div class="box">
<ul class="nobullet">
<li><strong>andworth:</strong> haha I really like that one</li>
<li><strong>andworth:</strong> haha I really like that one</li>
<li><strong>andworth:</strong> haha I really like that one</li>
<li><strong>andworth:</strong> haha I really like that one</li>
<li><strong>andworth:</strong> haha I really like that one</li>
</ul>
</div>
<!-- span for bottom of menu, replace with jquery -->
<span class="bottom"></span>
</div>
<div id="main">
<h2 class="sifr">THE WEREWOLF AND ME</h2>
<p class="joke">
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam blandit est eu lectus. Sed augue tortor, vehicula in, condimentum eget, tempor in, lectus. Integer enim leo, aliquam eget, hendrerit vel, laoreet a, turpis. Quisque sit amet ligula at quam condimentum ultricies. Sed molestie dolor non tellus. Vestibulum luctus nisi eget metus. Integer semper vestibulum nisl. Proin vel libero ac justo euismod sollicitudin. Duis a ligula sit amet quam fermentum convallis. Quisque tempus iaculis risus. Cras et libero vehicula lorem ultrices volutpat. Mauris quam quam, blandit et, facilisis in, sodales nec, libero. In massa tellus, varius non, luctus eu, facilisis rutrum, odio. Vivamus congue lacus quis metus.
<br /><br />
Nunc ultrices nisi ut tellus. In placerat tempus quam. Nulla dolor nulla, dictum eget, auctor a, rutrum sit amet, ante. Sed scelerisque est. Vestibulum arcu purus, dignissim nec, rhoncus id, sodales eu, quam. Nullam congue hendrerit enim. Phasellus risus. Pellentesque lacus sem, luctus tempus.
</p>
<div id="jokedetails">
<table>
<tr>
<td>Submitted By:</td>
<td>admin</td>
</tr>
<tr>
<td>Date Submitted:</td>
<td>26/2/09</td>
</tr>
<tr>
<td>Views:</td>
<td>1891</td>
</tr>
<tr>
<td>Average Rating:</td>
<td>4.5 / 5</td>
</tr>
</table>
<form action="http://superfunnyjokes.net/process/rating.php" method="post">
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
<input name="starrating" type="radio" class="star {split:2}" />
</form>
</div>
<h2 id="comments">Comments</h2>
<div class="comment">
<div class="left">
<img src="http://superfunnyjokes.net/members/avatars/noavatar.png" alt="No Avatar" />
</div>
<div class="right">
<h3>Ryan Polosky</h3>
<span>12 March 09</span>
<p>I found that joke really funny!</p>
</div>
</div>
<div class="comment">
<div class="left">
<img src="http://superfunnyjokes.net/members/avatars/noavatar.png" alt="No Avatar" />
</div>
<div class="right">
<h3>Laura Brauman</h3>
<span>12 March 09</span>
<p>Nunc ultrices nisi ut tellus. In placerat tempus quam. Nulla dolor nulla,
dictum eget, auctor a, rutrum sit amet, ante. Sed scelerisque est.
Vestibulum arcu purus, dignissim nec, rhoncus id, sodales eu, quam. Nullam
congue hendrerit enim. Phasellus risus. Pellentesque lacus sem, luctus
tempus.</p>
</div>
</div>
<div class="comment">
<div class="left">
<img src="http://superfunnyjokes.net/members/avatars/noavatar.png" alt="No Avatar" />
</div>
<div class="right">
<h3>James Brauman</h3>
<span>10 March 09</span>
<p>Haha! Good stuff!</p>
</div>
</div>
<h2 id="postcomment">Post Comment</h2>
<div class="postcomment">
<div class="left">
<img src="images/noavatar.png" alt="No Avatar" />
</div>
<div class="right">
<table>
<tr>
<td><label for="commentname">Your Name:</label></td>
<td><input id="commentname" type="text" name="commentname" /></td>
</tr>
<tr>
<td colspan="2"><textarea cols="0" height="0"></textarea></td>
</tr>
<tr>
<td></td>
<td><button type="submit">Post</button></td>
</tr>
</table>
</div>
</div>
</div>
<div id="footer">
</div>
</div>
</body>
</html>
“导航”标题下的整体<ul>正在消失，因为它充满了超链接。