Before the advent of CSS, designing web pages was completely arried within HTML, directly inside the content of the document. However, with the advent of CSS, fundamental separation of content and presentation of the document was made possible.
Due to this innovation it became possible to easily use a common look for the mass of similar documents, as well as a rapid change of registration.
A number of designs for different devices. For example, the screen design will be designed for a large width, while printing the menu will not be displayed, and the PDA and cell phone menu will follow the content.
Reducing the web pages load due to the transfer rules of data in a separate CSS file. In this case, the browser loads only the structure of the document and the data stored on the page. As well as the presentation of these data is downloaded by the browser only once and can be easily cached.
Ease of subsequent design changes. No need to edit each page, and the only change happens with the CSS file.
Additional design options. For example, using CSS layout you can make a block of text that will wrap around the rest of the text (such as menus), or to make sure that the menu is always visible while scrolling.
Different display layout in different browsers (especially older) which have different interpretations of the same CSS data.
A common need in practice corrects not only a CSS file, but the tags from HTML, which are complex and not obvious way related to the CSS selectors. This sometimes negates the ease of application as regards uniform style files, and significantly lengthens the editing and testing.
History and development of cascading style sheets (CSS)
CSS is one of the wide range of technologies approved by the W3C and has been generally termed standard for the Web. In the 1990s, the need to standardize the web became clear. Some common rules that programmers and web designers were amply justified. So there were HTML 4.01 and XHTML languages, and the standard CSS.
In the early 1990s, different browsers had their own styles to display Web pages. HTML developed very quickly and was able to meet all existing needs at the time for registration of information, so CSS then got wide recognition.
The term cascading style sheets was proposed by Håkon Wium Lie in 1994. Together with Bert Bos, he began to develop CSS.
Unlike many existing at that time, CSS uses inheritance from parent to child, so the developer can define different styles, based on the already defined styles.
In the mid-1990s, the World Wide Web Consortium (W3C) began to show interest in the CSS, and in December 1996 it published a recommendation for CSS.