Background images

In order to handle background images, we can use a special media query to determine the pixel ratio and then modify the background property to serve up the retina image. In this section, we'll determine how we can account for background images in the sphere of retina. We'll first create a media query designed for determining the pixel ratio. Then, we'll update the image being served to be the retina version. The seaweed in the footer is a background image, and thus will be the perfect image for this task.

Targeting the seaweed in the footer

Here is the seaweed just above the footer on the movies page:

If we look at the CSS, all that's happening is that the footer has a repeating background...