Tuesday 25th of July 2017 02:32:31 PM

CSS Style Guide

XHTML: Accessibility Tips

The library is committed to serving the entire public, and that means striving to ensure that all pages of our site are accessible to the greatest possible number of people and devices (including audio browsers, Braille readers, and other specialized browsing environments).

In addition, accessibility is now U.S. law for all government and publicly funded sites.

Education and Compliance

The following links can help you develop pages that comply with accessibility laws and guidelines:

WAI Accessibility Guidelines
These guidelines offer compliance tips, and outline various levels of compliance.
Bobby Accessibility Validator
The Center for Applied Special Technology has created this online tool that analyzes web page accessibility based on the W3C guidelines.

Accessibility and Web Standards

In a perfect world, the library’s website would be authored in XHTML 1.0 Strict, using absolutely no deprecated HTML “design” elements. Visual design would be handled via Cascading Style Sheets exclusively.

This strict separation of structure (XHTML) from style (CSS) would enable us to comply with the W3C's Priority One rating for User Agent Accessibility Guidelines 1.0, and would also vastly simplify the design, development, and maintenance of our site.

With such an approach, our site could look great in a standards–compliant browser, and yet remain accessible to virtually any known browser or Internet device.

The Bad News

Unfortunately, many web browsers used by our audience are not sufficiently CSS-compliant - over one third still use some version of Netscape 4.x. Happily, NYPL has upgraded our onsite PCs to Internet Explorer 5.5.

The Transitional Solution

In order to design sites that achieve at least a minimum of accessibility and that work well in Netscape 4, our pages must:

In addition, all XHTML and Style Sheets must validate, a simple process described on the very next page. »

« XHTML Section Index | XHTML Validation »

deal of extra blank space within the parent element.

Then there is the question of what happens to elements that flow past a floated element but have visible backgrounds. Let's take the preceding example and change it so that the second H3 element has a visible background and border, as has been done in Figure 7-69.

Figure 7-69

Figure 7-69. More floating images and element backgrounds

6.2.5. Getting Attached

Okay, so we can place the origin image for the background anywhere in the background of an element, and we can control (to a degree) how it tiles. As you may have already realized, setting an image to be in the center of the document may mean, given a sufficiently long document, that the background image isn't