Absolute Center

http://stackoverflow.com/questions/19644101/is-there-a-way-i-can-use-css3-calc-to-place-a-dialog-in-the-center-of-my-screen

by TastyBytes

HTML

<div>
    <h1>Perfectly Centered</h1>
    <h3>This is centered top to bottom and left to right</h3>
</div>

CSS

div {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    width: 50%;
    height: 150px;
    margin: auto;
    
    text-align: center;
    
    background: #deface;
}

body {
    font-family: sans-serif;
}