html{
	font-size:100%;
}

/* for IE/Win */
body{
	font-size:62.5%;
}

* html body {font:100.01%/1.4em}

/* for Others */
html>body {
	font-size:10px;
}

/* for IE/Win */
input, select, th, td {
	font-size:1em;
}

/* 

So Now 1em = 10px, 1.4em = 14px etc 

And For nested elements:

childPix / parentPix = childEms

10/16 = 0.65

*/