reverse the order of div's children

The modern answer is

#parent {
  display: flex;
  flex-direction: column-reverse;
}

A little bit tricky, but can work; just to give you the idea:

div#top-to-bottom {
    position: absolute;
    width:50px;
    text-align: left;
    float: left;
    -webkit-transform: scaleY(-1);
    transform: scaleY(-1);
}
div#top-to-bottom > div {
    width: 50px;
    height: 50px;
    position: relative;
    float: right;
    display: block;
    -webkit-transform: scaleY(-1);
    transform: scaleY(-1);
}

mirror in the vertical axis both the container and the childs. The childs follow the inverted y axis of the container, but the children themselves are again head up.

demo

<style>
#parent{
    display: -webkit-flex; /* Safari */
    -webkit-flex-direction: row-reverse; /* Safari 6.1+ */
    display: flex;
    flex-direction: row-reverse;
}
</style>