您可以复制并粘贴以下标记和 css 以查看效果。
问题存在于“页脚”部分。
现在“column1”和“column3”是绝对定位的。
它仅在“column2”最高时有效。
如何在所有条件下使“页脚”不与 column1~column3 交错？
标记：
<body>
<div id="mainwrap">
<div id="header"><p>A fluid-width faux-columns example</p></div>
<div id="contentarea" class="clearfix">
<div id="contentarea2" class="clearfix">
<div id="column2">
<p>This layout uses absolute/relative positioning to position the side columns within
their respective faux columns containers.</p>
<p>You can control the maximum and minimum widths of the fluid center area.
Once the layout reaches its maximum width, it centers itself in the browser as the window
gets wider.</p>
<p>Nulla scelerisque. Sed tincidunt. Quisque eu nisl. Phasellus
mi ante, aliquet vel, vestibulum sit amet, consectetuer non, ante. Suspendisse
consequat condimentum enim. Morbi vestibulum lorem sit amet enim. Nulla venenatis
fermentum purus.</p>
<p>Nunc justo nisl, vulputate in, sagittis in, pretium sodales,
magna. Nullam felis diam, bibendum ut, dictum in, tincidunt vitae, magna.
Nunc mattis congue leo.</p>
</div><!--end column2-->
<div id="column1">
<ul>
<li><a href="#">Link 1</a></li>
<li><a href="#">Link 2</a></li>
<li><a href="#">Link 3</a></li>
</ul>
</div><!--end column1-->
<div id="column3">
<p>This template uses the Alsett clearing method.</p>
</div><!--end column3-->
</div><!--end contentarea2-->
</div><!--end contentarea-->
<div id="footer">This is the footer</div>
</div><!--end mainwrap-->
</body>
CSS：
body {font: 1.0em verdana, arial, sans-serif;
text-align:center;
}
* {margin:0; padding:0;}
div#mainwrap {min-width:780px; max-width:960px;
margin-left:auto; margin-right:auto;
text-align:left;
}
div#header {height:32px; background-color:#CAF; text-align:center;}
div#contentarea { background-color:#FFF;
background:url(images_pres/faux_left.gif) repeat-y top left;
position:relative;
}
div#contentarea2 {background-color:#FFF;
background:url(images_pres/faux_right.gif) repeat-y top right;
position:relative;
}
div#column1 {width:150px;
position: absolute;
top:0px; left:0px;
background-color:#CCC;
overflow:hidden;
}
div#column2 {background-color:#FFF;
margin:0 170px 0 150px;
}
div#column3 {width:170px;
position:absolute;
top:0px; right:0px;
background-color:#DDD;
overflow:hidden;
}
div#footer {background-color:#FAC; text-align:center; padding-top:6px;}
div#column1 ul {margin: 20px 0 0 26px;}
div#column2 p {font-size:.8em; margin:0 30px 1em ;}
div#column3 p {margin: 20px 10px 0 10px;}