dynamic / responsive / liquid layout css

dynamic / responsive / liquid layout css

I was wondering if there is an alternative to writing css rather than with
css tables to make liquid / dynamic layouts. vinyll really helped me
here... simple 3 Column responsive layout
and that is exactly how I need the columns to work, but when I use css
tables, it seems I cannot position things inside with margin and padding
(I probably could with left and right but relative positing breaks the
document flow so I don't want to do that)...heres and example
http://jsfiddle.net/u5nR2/4/
.container{
width:100%;
height:100%;
display: table;
}
div > div {
display: table-cell;
}
.three div{margin-top:100px}/*why doesnt this move?*/