The Mystery of CSS
Every website you see nowadays incorporates at least some Cascading Style Sheet (CSS) in their web design. It’s a breakthrough in web design technology that runs off from the old norm of using tables and frames. It gives you certain flexibility that is unheard off before, but what is it all about?
What is CSS?
HTML, when it was first introduced, was never meant to handle presentation over the monitor screen. It was intended to display and format text, that’s all. CSS was created when the HTML contains too many formatting tags that become a burden to the coding process, thus making HTML coding inefficient.
CSS itself isn’t perfect, but it is also not faulty. It works in ways that it really should. The problem comes only when it comes to Internet Explorer (IE). IE is a buggy, unsecure web browser that is based on a very old technology. Microsoft have never fixed it and nor will it ever be fixed. Hence, there is a need for hacks for CSS to work in a cross-browser context.
There are hundreds of CSS bugs that have been documented in various versions of Internet Explorer, Netscape Mozilla, and Opera, many of which reduce the legibility of documents. The proliferation of such bugs in CSS implementations has made it difficult for designers to achieve a consistent appearance across platforms.
Currently there is strong competition between Mozilla's Gecko layout engine, Opera's Presto layout engine, and the KHTML engine used in both Apple's Safari and the Linux Konqueror browsers - each of them is leading in different aspects of CSS. Internet Explorer remains the worst at rendering CSS by standards set down by World Wide Web Consortium as of 2005.
These problems have precisely led the W3C to revise the CSS2 standard into CSS2.1, which may be regarded as something of a working snapshot of current CSS support. CSS2 properties which no browser had successfully implemented were dropped, and in a few cases, defined behaviours were changed to bring the standard into line with the predominant existing implementations.
What makes CSS important?
Separation of Content and Presentation is the key. Authors can finally influence the presentation of documents without leaving pages unreadable to users.
A CSS is made up of style rules that tell a browser how to present a document. There are various ways of linking these style rules to your HTML documents, but the simplest method for starting out is to use HTML's STYLE element. This element is placed in the document HEAD, and it contains the style rules for the page.
Functionality and Usage of CSS
CSS is well-designed to allow the separation of presentation and structure. Prior to CSS, nearly all of the presentational attributes of an HTML document were contained within the HTML code; all font colors, background styles, element alignments, borders and sizes had to be explicitly described, often repeatedly, in the midst of the HTML code.
CSS allows authors to move much of that information to a stylesheet, resulting in considerably simpler HTML code. The HTML documents become much smaller and web browsers will usually cache sites' CSS stylesheets. This leads to a reduction in network traffic and noticeably quicker page downloads.
For example, the HTML element h2 specifies that the text contained within it is a level two heading. It has a lower level of importance than h1 headings, but a higher level of importance than h3 headings. This aspect of the h2 element is structural.
Customarily, headings are rendered in decreasing order of size, with h1 as the largest, because larger headings are usually interpreted to have greater importance than smaller ones. Headings are also typically rendered in a bold font in order to give them additional emphasis. The h2 element may be rendered in bold face, and in a font larger than h3 but smaller than h1 . This aspect of the h2 element is presentational.
Prior to CSS, document authors who wanted to assign a specific color, font, size, or other characteristic to all h2 headings had to use the HTML font element for each occurrence of that heading type.
Moreover, CSS can be used with XML, to allow such structured documents to be rendered with full stylistic control over layout, typography, color, and so forth in any suitable user agent or web browser.
CSS drawbacks
CSS may at times be misused, particularly by the author of web documents. Some developers who are accustomed to designing documents strictly in HTML may overlook or ignore the enabling features of CSS. For instance, a document author who is comfortable with HTML markup that mixes presentation with structure may opt to use strictly embedded CSS styles in all documents. While this may be an improvement over using deprecated HTML presentational markup, it suffers from some of the same problems that mixed-markup HTML does; specifically, it entails a similar amount of document maintenance.
CSS in a nutshell
CSS is used by both the authors and readers of web pages to define colors, fonts, layout, and other aspects of document presentation. It is designed primarily to enable the separation of document structure (written in HTML or a similar markup language) from document presentation (written in CSS).
CSS not only allows the separation of content and presentation. It can also help separate different types of presentation formats, such as one for the display, one for printing view and one for voice recognition or Braille.
CSS allows complete and total control over the style of a hypertext document. The only way this can be illustrated in a way that gets people excited is by demonstrating what it can truly be, once the reins are placed in the hands of those able to create beauty from structure.
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