What is CSS?
What is CSS
What is CSS
C ascading S style S heets, referred to as
Strictly speaking, CSS isn’t a programming language, but it does require abstract thinking. It’s also not just a design tool, but it does require some creativity.
Where We Use CSS
CSS is widely used in both web-based and non-web-based applications:
- All modern websites use CSS to style their pages.
- Embedded device displays often use CSS to design their user interfaces.
- RSS clients also allow you to apply CSS to subscriptions and feed entries.
- Instant messaging clients also use CSS to format chat windows.
Some aspects of CSS can be found in the syntax used by JavaScript and its frameworks, so it’s fair to say that CSS is everywhere!
History of CSS
Cascading Style Sheets Level 1 (CSS1) became a W3C Recommendation in December 1996. This version describes the CSS language and a simple visual formatting model for all HTML tags.
CSS2 became a W3C Recommendation in May 1998, building on CSS1. This version added support for media-specific style sheets (such as for printers and audio devices), downloadable fonts, element positioning, and tables.
CSS3 became a W3C Recommendation in June 2012, building on the older version of CSS. It is divided into documents called modules, each with new and extended features defined in CSS2.
| Year | Description |
|---|---|
| 1994 | HÃ¥kon Wium Lie proposed using CSS to allow web designers to change the layout, colors, and fonts of websites. |
| 1996 | The first version of CSS was released, and the newly formed CSS Working Group continued work on CSS2. |
| 1998 | The second version of CSS was released, and work on CSS-3 began. |
| 2011 | A revised version of CSS2, CSS2.1, was released, fixing bugs found in CSS 2. |
| 2012 | As of June 2012, the CSS-3 Working Group had released over 50 CSS modules. |
Myths about CSS4
Yes, the myth about CSS4 is a myth, so let me tell you there was never a CSS4. There will never be a CSS4. CSS4 does not exist.
How CSS Works
First, we use CSS to define rules to apply styles like fonts, colors, sizes, etc. Under different conditions, we want certain things to happen, such as if element X is a child of element Y, apply these styles. Next, these classes are added to HTML elements. The browser then looks at these rules, figures out which rules apply where, and uses them to render the page.
Sources of Style Sheets
The style sheets you add to a web page aren’t the only style sheets that browsers apply. There are different types, or sources, of style sheets:
- User-agent styles – These are the default styles that the browser applies to any web page.
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Author styles – Your style sheets are called author styles, and they can override user-agent styles.
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User style sheets – Some browsers allow users to define user style sheets, but these are rarely used.
Who Maintains CSS
CSS is created and maintained by a group of people within the W3C, called the CSS Working Group. The CSS Working Group creates documents called specifications. When a specification is discussed and formally approved by W3C members, it becomes a recommendation.
These approved specifications are called recommendations because the W3C has no control over the actual implementations of the language. Independent companies and organizations create the software.
The World Wide Web Consortium (W3C) is an organization that publishes recommendations for how the internet works and evolves.
CSS Modules
A CSS module is a CSS file in which all class names and animation names are locally scoped by default. CSS3 has many modules, and we’ll list some of them:
- Selectors
- Box Model
- Backgrounds and Borders
- Image Values and Replaced Content
- Text Effects
- 2D/3D Transformations
- Animation
- Multi-column Layout
- User Interface