CSS 'pixels' are a dark, dark magic, come back to the light! CSS pixels are a measure of your viewing angle, the physical measurement of the device, and your s

CSS 'pixels' are a dark, dark magic, come back to the light! CSS pixels are a measure of your viewing angle, the physical measurement of the device, and your screen's pixel density. Basically 15px should look like 15px should look like 15px, no matter what you're looking at, but because the actual pixel densities of screens differ it can be really weird to think about. You may need a 30px icon to display 15px wide on a retina screen, even though it sounds like a 15px image should be 100% large (and therefore crisp) at 15px in CSS.