Re: lynx-dev what are cascading style sheets?

[David Woolley]

> 
> 
> Could someone give a brief description of what cascading style sheets are?

They are a mechanism for separating content from form, which allows a
good author to write well structured HTML but still produce a lot of
graphical markup on suitable browsers.  They allow typical authors to
produce even more inpenetrable pages, because they will push the graphical
side beyond the limits, for "competetive advantage", without any thought to
the real concepts behind style sheets.

Correct use requires that the author think about the structure of a 
document, rather than arbitrarily just paint blocks of words in particular
colours, fonts, etc.  Very few people seem able to handle that level of
abstraction.

Having said that, a typical use would be to get graphical bullet point
markers.  The most common way is:

<p><img src=...> bullet point</p>
....

a better way is:

<dl>
  <dd> <img ...> bullet point
....
</dl>

because at least it is clear that it is a list.

However the style sheets way is:

<ul class="type-of-list">
<li> point 1
<li> point 2
....
</ul>

Together with a style sheet that says:

ul.type-of-list li { list-style: url(http://....../...gif) disc; }

which specifies the URL for the graphic bullet and that a disc shape
should be used if there is no support for graphic bullets.

You can also divide a document up into divisions and position these on the
page using style sheets.  Unfortunately, some of the early GUI implementations
of this are quite badly broken, so it may be a long time before it becomes
common place in pages designed for accessibility.

Using style sheets, it is possible (by using an external style sheet) to
write a page which is valid and well structured HTML 2.0, but still exhibits
background textures, graphic bullets, multiple fonts, etc. on a style sheet
aware browser.

Like most other such things, you really need to access http://www.w3.org/
for details on web technology.