The flexible box model
CSS 3 introduces a brand new box model in addition of the traditional box model from CSS 1 and 2. The flexible box model determines the way boxes are distributed inside other boxes and the way they share the available space.
This box model is similar to the one used by XUL (the user interface language used by Firefox). Some others languages use similar box models such as XAML or GladeXML.
Usually the flexible box model is exactly what you need if you want to create fluid layouts which adapt themselves to the size of the browser window or elastic layouts which adapt themselves to the font size.
