Cascading Style Sheets — or Css — is the first technology you should start learning after HTML. While HTML is used to define the structure and semantics of your content, Css is used to style it and lay it out. For example, you can use Css to alter the font, color, size, and spacing of your content, split it into multiple columns, or add animations and other decorative features....Cascading Style Sheets — or CSS — is the first technology you...and semantics of your content, CSS is used to style it and lay it...