CSS fluid columns, fixed margins; the holy grail of holy grails

Question

Update & Summary

I feel obligated to make this question clearer, now that there is a bounty attached.

(Also, I\'m pretty sure this will be child\'s

Answer 1

Why don't you use

.column > .panel {
    padding: 10px 0 10px 10px;
}

.column:first-child > .panel {
    padding-left: 0px;
}

It will make 10px spaces only between boxes and without using last-child.