However, as the Internet expanded from the academic and research world into the mainstream in the mid-1990s, and became more media oriented, graphic designers sought ways to control the visual appearance of their Web pages.
The use of graphic editors with slicing tools that output HTML and images directly also promoted poor code with tables often having many rows of 1 pixel height or width.
Furthermore, when a table-based layout is linearized, for example when being parsed by a screen reader or a search engine, the resulting order of the content can be somewhat jumbled and confusing.
HTML tables still have their legitimate place when presenting tabular information within web pages,[3] and are also sometimes still used as layout devices in situations for which CSS support is poor or problematical, like vertically centering an element.
The CSS1 specification was published in December 1996 by the W3C[4] with the aim of improving web accessibility and emphasising the separation of presentational details in style sheets from semantic content in HTML documents.
There are bandwidth savings as large numbers of semantically meaningless
| tags are removed from dozens of pages leaving fewer, but more meaningful headings, paragraphs and lists. Layout instructions are transferred into site-wide CSS stylesheets, which can be downloaded once and cached for reuse while each visitor navigates the site. New HTML content can be added in such a way that consistent layout rules are immediately applied to it by the existing CSS without any further effort. As a result of the separation of design (CSS) and structure (HTML), it is also possible to provide different layouts for different devices, e.g. handhelds, mobile phones, etc. It is also possible to specify a different style sheet for print, e.g. to hide or modify the appearance of advertisements or navigation elements that are irrelevant and a nuisance in the printable version of the page. According to the basic capabilities of HTTP, as these rarely change and they apply in common to many web pages, they will be cached and reused after the first download. |