Text Scalability


One particular CSS accessibility problem has to do with text resizing. It's tempting to choose a smaller font size for your work to fit more information on the screen at once. We all know how little space we're given to work with onscreen anyway, so there's a justified rationale for going smaller.

The problem is that many people just can't read text below a certain size. For some, 12-pixel-high text is unreadable, and in extreme cases even 24 pixels is too small. Of course, no one is going to start designing with 24-pixel-high body copy on today's low-resolution monitors, so there has to be a compromise somewhere.

Fortunately all modern browsers have some form of font-resizing mechanism built in. Not all users know where to find this tool in their browsers, but for those who do it's invaluable. The problem comes in when font-size values are specified with the px units. Internet Explorer will scale fonts that are sized using em or %, but it won't scale the px unit.

So any help that users might have received from their browsers is of no use, and the problem persists. If the designer avoids the px unit, everything should be fine, right? Probably, but Chapter 5 covers some entirely different problems that might be encountered when using em or % units.

Even if text is scalable in all browsers, though, there's something else to consider: The design must also allow for scaling (FIGURE 15). That sounds easy, but if you blend fixed-size elements (like a 20px-high background image) with elements that are variable (like text that the viewer has resized from 14px to 24px), you'll quickly notice that a design that relies on fixed sizing can break down very quickly when the font is different from what the designer expected. Most Zen Garden designs have been tested for this condition and can be resized quite a bit larger than their default.

Figure 15. Text is scalable, even if images and proportions aren't.


Note

A List Apart has more on XHTML and the various DOCTYPEs you can choose from (www.alistapart.com/articles/doctype).


The lesson learned is that whatever size you choose for your text, chances are that someone is going to want it larger. It's important to be aware of the potential problems they may face when trying to make the text larger, and accomodate them when reasonable to do so.



    The Zen of CSS Design(c) Visual Enlightenment for the Web
    The Zen of CSS Design(c) Visual Enlightenment for the Web
    ISBN: N/A
    EAN: N/A
    Year: 2005
    Pages: 117

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