继续水平垂直居中

by redky

HTML

<div class="box">hello</div>
<div class="help"></div>
<!--
http://www.w3.org/TR/2012/WD-css3-sizing-20120927/#width-height-keywords
-->

CSS

.box {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    border: 1px solid #000;
    margin: auto;
    height: -webkit-fit-content;
    width: -webkit-fit-content;
}

.help {
    height: 1000px;
}