Skip to main content

CSS: Different versions with variations

CSS 1:
The first CSS specification to become an official W3C Recommendation is CSS level 1, published in December 1996. Among its capabilities are support for

    Font properties such as typeface and emphasis
    Color of text, backgrounds, and other elements
    Text attributes such as spacing between words, letters, and lines of text
    Alignment of text, images, tables and other elements
    Margin, border, padding, and positioning for most elements
    Unique identification and generic classification of groups of attributes

The W3C no longer maintains the CSS 1 Recommendation.



CSS 2:
CSS level 2 specification was developed by the W3C and published as a recommendation in May 1998. A superset of CSS 1, CSS 2 includes a number of new capabilities like absolute, relative, and fixed positioning of elements and z-index, the concept of media types, support for aural style sheets and bidirectional text, and new font properties such as shadows.

The W3C no longer maintains the CSS 2 recommendation.

CSS 2.1:
CSS level 2 revision 1, often referred to as "CSS 2.1", fixes errors in CSS 2, removes poorly supported or not fully interoperable features and adds already-implemented browser extensions to the specification. In order to comply with the W3C Process for standardizing technical specifications, CSS 2.1 went back and forth between Working Draft status and Candidate Recommendation status for many years. CSS 2.1 first became a Candidate Recommendation on February 25, 2004, but it was reverted to a Working Draft on June 13, 2005 for further review. It returned to Candidate Recommendation on 19 July 2007 and then updated twice in 2009. However, since changes and clarifications were made, it again went back to Last Call Working Draft on 7 December 2010.

CSS 2.1 went to Proposed Recommendation on 12 April 2011. After being reviewed by the W3C Advisory Committee, it was finally published as a W3C Recommendation on 7 June 2011.

CSS 3:

Unlike CSS 2, which is a large single specification defining various features, CSS 3 is divided into several separate documents called "modules". Each module adds new capabilities or extends features defined in CSS 2, over preserving backward compatibility. Work on CSS level 3 started around the time of publication of the original CSS 2 recommendation. The earliest CSS 3 drafts were published in June 1999.

Due to the modularization, different modules have different stability and statuses.  As of June 2012, there are over fifty CSS modules published from the CSS Working Group., and four of these have been published as formal recommendations:

Some modules (including Backgrounds and Borders and Multi-column Layout among others) have Candidate Recommendation (CR) status and are considered moderately stable. At CR stage, implementations are advised to drop vendor prefixes.

CSS 3 also supports adding round edges to elements via the border-radius property. Increasingly more websites are utilizing this technique for aesthetic purposes.


CSS 4:
There is no such thing as CSS4.

Since CSS3 split the CSS language's definition into modules, the modules have been allowed to level independently. Most modules are level 3 - they build on things from CSS 2.1. A few level 4 modules exist (such as Image Values, Backgrounds & Borders, or Selectors), which build on the functionality of a preceding level 3 module. Others are level 1 because they define entirely new functionality, such as Flexbox.

So, while one can discuss upcoming levels of individual modules, there is no monolithic "CSS4" which will be worked on after "CSS3" is finished.

Comments

Popular posts from this blog

MySQL Connection

Connection with MySQL Database Before accessing database, you must create a connection to the database Syntax: mysql_connect(servername,username,password); where, servername specifies the server to connect to. Default value is “localhost” username specifies the username to log in with. Default value is the name of the user that owns the server process. To connect offline we use username “root”. password specifies the password to log in with. Default is “” Code : Creating connection to the database and selecting the required database <?php $con = mysql_connect(“localhost”,”root”,”"); if (!$con) { die(‘Could not connect: ‘ . mysql_error()); } else{ mysql_select_db(“test”, $con) }; ?> Here, we have store connection in a variable called $con and trap error using die function. Closing connection The connection will be closed automatically when the script ends. To close the connection before, use the mysql_close() function: <?php $con = mysql_conne...

Type Juggling and Type Casting

Type Juggling: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which the variable is used. That is to say, if a string value is assigned to variable $var, $var becomes a string. If an integer value is then assigned to $var, it becomes an integer.

Doctype Defination

A Document Type Declaration, or DOCTYPE, is an instruction that associates a particular SGML or XML document (for example, a webpage) with a Document Type Definition (DTD). Syntax The general syntax for a document type declaration is: <!DOCTYPE root-element PUBLIC "FPI" ["URI"] [ <!-- internal subset declarations --> ]>