Fluid Layout and Flexbox

At the end of the last chapter, we reminded ourselves that the three core tenets of responsive web design are fluid layout, media queries, and flexible media. We spent Chapter 3 learning all about media queries. Now we know how to wield them to change a layout at a particular breakpoint. In this chapter, we will focus on another pillar of responsive web design: fluid layout.

Eons ago, in the mists of time (well, the late 1990s), websites were typically built with their widths defined as percentages. These percentage-based widths fluidly adjusted to the screen and were known as fluid layouts.

In the years after, in the mid-to-late 2000s, there was an intervening fixation on fixed-width designs—I blame those pesky print designers and their obsession with pixel-perfect precision! Nowadays, as we build responsive web designs, we need to look back to fluid layouts and remember all the benefits they offer.

Until fairly recently, web developers...