HTML and CSS Reference
In-Depth Information
that technologies for downloadable fonts vary significantly between browsers. Appendix B
discusses some approaches to using custom fonts online.
Miscellaneous CSS3 Changes
One of the things about CSS3 that may surprise developers is that it makes subtle changes
in a number of places rather than introducing all new properties. We see many new list-type
values like
arabic
,
binary
,
lower hexadecimal
,
mongolian
,
thai
,
ethiopic
,
hangul
,
norwegian
,
somali
, and many more. Many more cursor values are introduced for more
application-style Web development like
alias
,
context-menu
, and
not-allowed
. A full
list can be found in the
cursor
property entry in the previous chapter.
Where possible, we alluded to these more subtle changes in the previous chapter's
reference when they were supported by browsers. Though, without looking at all entries
globally, you might not see how some CSS3 changes have wide effect. For example, CSS3-
compliant browsers should support multiple backgrounds. Here, we specify different files
for the background, each separated with a comma:
body {background: white url(donkey.gif) top left no-repeat,
url(elephant.gif) bottom right no-repeat;}
This would also work on the
background-image
property, of course, given
background
is just a shorthand for all background characteristics. So we see that once you
can specify multiple background images, this ripples through numerous properties like
background-position
. For example, when using
background-position
on different
backgrounds, we apply the position to each background in order, so
background-position: 50px 100px, 200px 200px;
would position the first background at 50px, 100px and the second background at 200px,
200px. Similarly, other background properties like
background-repeat
would change in
a similar manner, so
background-repeat: no-repeat, repeat-x;
would apply
no-repeat
to the first background and
repeat-x
to the second.
The CSS3 background changes are supported at the time of this edition's writing at least
in WebKit-based browsers. We focus in this chapter mostly on those areas of CSS3 where we
have a close-to-final specification (for example, Selectors) or have some implementation to
reference. While we have some good sense about what CSS3 features are likely to be
supported by browsers, it makes little sense to speculate too much until it is something
implemented and actually used by a Web developer or designer.
Implemented CSS3 and Browser-Specific Features
The CSS3 specification is far from complete, numerous aspects of the various proposed
modules that make up the specification have not been worked on for years, and there are
clearly many holes. However, browser vendors have implemented a number of properties
already. Further, many browser vendors have introduced proprietary extensions to CSS,
some of which have then been added to the CSS specification and some of which haven't.
