Introduction of css ...

INTRODUCTION

• CSS stands for Cascading Style Sheets

• CSS describes how HTML elements are to be displayed on screen, paper, or in other media

• CSS saves a lot of work. It can control the layout of multiple web pages all at once

• External stylesheetsare stored in CSS files. 

Who Creates and Maintains CSS?

• CSS was invited by Håkon Wium Lie on October 10, 1994 and maintained through a group of people within the W3C called the CSS Working Group. The CSS Working Group creates documents called specifications. When a specification has been discussed and officially ratified by W3C members, it becomes a recommendation.

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  These ratified specifications are called recommendations because the W3C has no control over the actual implementation of the language. Independent companies and organizations create that software.

CSS Versions

• Cascading Style Sheets, level 1 (CSS1) was came out of W3C as a recommendation in December 1996. This version describes the CSS language as well as a simple visual formatting model for all the HTML tags.
• CSS2 was became a W3C recommendation in May 1998 and builds on CSS1. This version adds support for media-specific style sheets e.g. printers and aural devices, downloadable fonts, element positioning and tables.
• CSS3 was became a W3C recommendation in June 1999 and builds on older versions CSS. it has divided into documentations is called as Modules and here each module having new extension features defined in CSS2.
• CSS3 Modules
  • CSS3 Modules are having old CSS specifications as well as extension features.
  • Selectors
  • Box Model
  • Backgrounds and Borders
  • Image Values and Replaced Content
  • Text Effects
  • 2D/3D Transformations
  • Animations
  • Multiple Column Layout
  • User Interface 

Why Use CSS?

• CSS is used to define styles for your web pages, including the design, layout and variations in display for different devices and screen sizes. 

• CSS Solved a Big Problem

• HTML was NEVER intended to contain tags for formatting a web page!

• HTML was created to describe the content of a web page, like:

                <h1>This is a heading</h1>

                <p>This is a paragraph.</p>

• When tags like <font>, and color attributes were added to the HTML 3.2 specification, it started a nightmare for web developers. Development of large websites, where fonts and color information were added to every single page, became a long and expensive process.

• To solve this problem, the World Wide Web Consortium (W3C) created CSS.

• CSS removed the style formatting from the HTML page!