Re: Using different style sheets for different screen resolutions.

Fabrice Magnan de Bornier wrote:
> I would like to create pages that would refer to several style
> one of them would be selected by the browser depending on the
> of the screen; I think this would be useful for example for the font
> size, which need not be the same on a 640x480 screen and on a
> screen.

Customizing your WWW documents based on the reader's display resolution
is a serious mistake, because...

(1) Screen resolution is related to the physical dimensions of the
display. If the reader is running 1024 x 768 on a 21" display, they may
be using small fonts to utilize as much of the available real estate as
possible. If the reader is running 1024 x 768 on a small screen, they
may be using large fonts for legibility. You have no way of knowing the
reader's needs and/or preferences without asking.

(2) Screen dimensions are not the same as window size. Most readers
with large, high-resolution displays will run their browser in a
window, not full-screen. Any customization of content should be
relative to the browser window, not the screen.

I believe the method most likely to give a reader legible type is to
use only em or percentage values because these numbers will be relative
to the reader's preferred size.

The reader sets their preferred default font size in their browser. You
can (theoretically) access this in CSS using em or percentage values.
For example, you might want to specify font-size for P at 1.2em and
font-size for H1 at 2em. Your paragraph text will then be 1.2 times as
large as the reader's preferred default for BODY and your H1 headings
will be 1.7 times as large as your paragraph text.

David Perrell