Cascading Style Sheets (CSS) is a simple mechanism for adding style (e.g., fonts, colors, spacing) to Web documents. CSS (Cascading Style Sheets) consist of a group of formatting rules that you use to control the layout and appearance of the content on a web page. CSS3 provides powerful features like animation, gradients, media queries, shadows, transitions, the font-face rule and many more.
"There is no design without discipline. There is no discipline without intelligence."
by Massimo Vignelli