Page 88 - GIGW2

CH 07 Development

7.2

Cascading Style Sheets (CSS)

Cascading Style Sheets (CSS) is a style sheet language used to describe the presentation
of a document written in a markup language. Its most common application is to style
web pages written in HTML and XHTML. The CSS specifications are maintained by the
World Wide Web Consortium (W3C). Its current specifications is CSS3.
CSS is used by both the authors and readers of web pages to define colours, fonts,
layout, and other aspects of document presentation. It is designed primarily to enable
the separation of document content from document presentation. This separation can
improve content accessibility, provide more flexibility and control in the specification
of presentational characteristics, and reduce complexity and repetition in the structural
content. CSS can also allow the same markup page to be presented in different styles for
different rendering methods, such as on-screen, in print, by voice (when read out by a
speech-based browser or screen reader) and on Braille-based, tactile devices.

To know more about CSS, visit
http://www.w3.org/Style/CSS/.

Advantages of using CSS include:
• Presentation of information for an entire website or collection of pages can be
held in one CSS file, allowing global changes to be propagated quite conveniently.
• Web browser software can store a copy of the CSS file in the computer’s cache,
so that it doesn’t have to be downloaded each time the user views a web page that
references it, hence improving the access time.
• Different users and screen readers can have different style sheets: for example a
large text alternative for visually impaired users or a layout optimised for small
displays for mobile phones.

• The document code is reduced in size and complexity, since it does not need to
contain any presentational markup.

7.2.1 Therefore Indian Government websites should use Cascading Style Sheets to
control layouts/styles and MUST make the interface responsive to cater to a wide
range of screen sizes.
7.2.2 Websites that use style sheets should ‘degrade’ gracefully so that the site remains
fully functional even if the stylesheet settings are ignored. Therefore the Web pages
in Indian Government websites MUST have the same logical order without the
style sheets as they have with the style sheets.

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