Cascading style sheets (CSS) give the designer of a web page the ability to separate the styling elements from the content. They are of fundamental importance to the usability of a page.
It is essential that pages are still usable (graceful degradation) when CSS are not supported by a browser.
CSS are the preferred method to control layout and formatting. Do not use tables as a means to control the layout or formatting of a page.
Influences on this standard
UK Government Guidelines
Central Office of Information guidelines - Delivering Inclusive Websites
"Consistent design (is)
achieved through the use of Cascading Style Sheets where the web developer can reuse the same layout and design for each page in the website. This can be helpful users with cognitive impairments, and benefits all users".
W3C Web Accessibility Initiative
W3C guideline 5
"Tables should be used to mark up truly tabular information.... Content developers should avoid using them to lay out pages."