I know how to set two divs stacked one before the other to make the second fill all the page's height if they are defined with percentages, but how if the first div's height is defined in "em"?
body{
height:100%;
background-color:yellow;
}
#Header{
height:3em;
border:solid 2px black;
background-color:red;
}
#Content{
border:solid 2px black;
background-color:green;
height:To fill body.. ????
}
Here is the Fiddle. (Updated)