History of Style Sheets
What is a Style Sheet?
A style sheet is a file or form that describes the layout and appearance of a document. Web designers have advocated style sheets for HTML and XHTML because they separate document presentation from document content. Several style sheet languages exist, but the most commonly used on the Web by far is the Cascading Style Sheets language, also known as CSS.
Like HTML and XHTML, the specifications for CSS are maintained by the World Wide Web Consortium (W3C), and like those languages, several versions of CSS exist with varying levels of browser support.
The first version of CSS, called CSS1, was introduced in 1996, but was not fully implemented by any browser for another three years. CSS1 introduced styles for the following document features:
- Fonts: Setting font size, type, and other properties
- Text: Controlling text alignment and applying decorative elements such as underlining, italics, and capitalization to text
- Color: Specifying background and foreground colors of different page elements
- Backgrounds: Setting and tiling background images for any element
- Block-level Elements: Controlling margins and borders around blocks, setting the padding space within a block, and floating block-level elements on a page like inline images
The second version of CSS, CSS2, was introduced in 1998. It expanded the language to support styles for:
- Positioning: Placing elements at specific coordinates on a page
- Visual Formatting: Clipping and hiding element content
- Media Types: Creating styles for different output devices, including printed media and aural devices
- Interfaces: Controlling the appearance and behavior of system features such as scrollbars and mouse cursors