: table;) ，内部子元素定为table-cell (display: table-cell),通过vertical-align特性使其垂直居中，但非标准浏览器是不支持的。
body {padding: 0;
;margin: 0;}
body,ht
ML{h
eight: 100%;}
#outer {height: 100%; overflow: hidden; pos
ITion: relative;width: 100%; background:ivory;}
#outer[id] {display: table; position:
static;}
#middle {position: absolute; top: 50%;} /* for e
xplorer only*/
#middle[id] {display: table-cell; vertical-align: middle; position: static;}
#inner {position: relative; top: -50%;width: 400px;mar
gin: 0 auto;} /* for explorer only */
div.greenBorder {border: 1px solid green; background-color: ivory;}
<div id="outer">
<div id="middle">
<div id="inner" class="greenBorder">
</div>
</div>
</div>