columns-example.css

w = container width
s = spacing
n = amount of columns

=====
 CSS
=====

.columns {
    width: w; /* Width is purely optional. Static, non-floating block elements default at 100% */
    overflow: hidden; /* We have floating child elements, we need to keep them inside -- hide the doors. Damn kids. */
}
    /**
     * Define spacing
     * ==============
     * Typically you want to have 20px for spacing, s = 20px
     **/
    .columns > div { margin: 0 s 0 0; }
    .columns > .last { margin: 0; } /* The "last" column needs to have its margin killed */
    
    /**
     * Define widths
     * =============
     * For four columns, n = 4.
     * For three columns, n = 3.
     **/
    .columns.four > div { width: (w - s(n - 1))/n); }

======
 HTML
======

div.columns.four
    div
    div
    div
    div.last