CSS stands for Corporate Style Shepherding and derives its name from the method by which styles are tamed. The programmer will herd their styles from the wild hilltop of asthetics down into the paddock of design. Styles become tools of creativity to reproduce the internet in a more colourful manner.
Style husbandry dates back to cavemen times when they were hunted in the wild, skinned and mounted on the walls of their caves. It wasn't until the birth of the computer that this process got streamlined and made more efficient. With large processing powers, computers can harness great swarms of styles to be controlled at once and organised into design systems.
In recent years CSS has advanced in its efficiency through the use of a fencing system known as Boundry Environment Modification or BEM for short.
To find out about how to organise CSS check out CSS wizardry or maybe even give Tachyons a go.