Chapter 14. Non-Screen Media
Not everyone who accesses the Web can see the effects
we've discussed in this book. Some 1.1 million
people in the United States are blind, and, obviously, they have a
very different experience of the Web than sighted persons.
Happily, CSS is not silent on the matter of non-visual access. CSS2
included the ability to apply styles in non-screen media. While the
Web has seen most of its evolution take place on monitors—that
is to say, in a visual medium—CSS2 can be used in non-visual
media, assuming that the user agent has proper support.
The advantages of designing documents that are at once visually and
non-visually usable should not be dismissed. If you can take one
document and use different, medium-specific style sheets to restyle
it for screen, print, and aural rendering, you can save yourself a
whole lot of trouble. For example, you would have no need to link to
"printer-friendly" versions of a
page. Instead of creating totally different markup structures, one
for screen and another for print, you can make your site more
efficient by reusing the same document.
For that matter, it's possible to take a single HTML
document that contains the outline of a slideshow and style it for
easy reading on a screen, for clean and readable printouts, as a
slideshow, and in a manner that a screen reader can translate. In the
course of this chapter, we'll look at ways to do the
latter three (since the rest of the book concerns itself with screen
presentation).
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