/* These are the base rule to set the dead center */

​

.parent

{

  position : relative;

}

​

.child

{

  position : absolute;

​

  top: 0 ;

  right: 0 ;

  bottom : 0 ;

  left : 0 ;

​

  margin : auto;

}

​

/* these are addtional rules */

​

.parent

{

  width : 300px;

  height: 300px;

  background : red;

}

​

.child

{

  width:100px;

  height:100px;

  background:blue;

  text-align:center;

  line-height:100px;

}