html中 css怎么讲div顶置,css：如何将box div元素直接置于中心？

非常奇怪的CSS“语言”并没有提供一种简单的方法来将元素置于屏幕中心。必须制作Kludges！这是我在高度和宽度都是AUTO的元素的唯一解决方案。试用FF19(Win + Mac)，CH25(Win + Mac)和IE9。

.overlay {

position:absolute;

top:0;

left:0;

width:100%;

height:100%;

background-color:#eee; /* aesthetics as you wish */

}

.overlay .vref { /* it is a vertical reference to make vertical-align works */

display:inline-block;

vertical-align:middle; /* this makes the magic */

width:1px;

height:100%;

overflow:hidden;

}

.overlay .message {

display:inline-block;

padding:10px;

border:2px solid #f00; /* aesthetics as you wish */

background-color:#ddd; /* aesthetics as you wish */

vertical-align:middle; /* this makes the magic */

max-width:100%; /* prevent long phrases break the v-alignment */

}

whatever you want goes here