Imported Style Sheet is a sheet that can be imported to (combined with) another sheet. This allows creating one main sheet containing declarations that apply to the whole site and partial sheets containing declarations that apply to specific elements (or documents) that may require additional styling. By importing partial sheets to the main sheet a number of sources can be combined into one.
To import a style sheet or style sheets include the @import notation or notations in the STYLE element. The @import notations must come before any other declaration. If more than one sheet is imported they will cascade in order they are imported - the last imported sheet will override the next last; the next last will override the second last, and so on. If the imported style is in conflict with the rules declared in the main sheet then it will be overridden.
<LINK REL=STYLESHEET HREF="main.css" TYPE="text/css">
.... other statements
Style sheets are the way that standards-compliant Web designers define the layout, look-and-feel, and design of their pages. They are called Cascading Style Sheets or CSS. With style sheets, a designer can define many aspects of a Web page:
Style sheets give you a lot of power to define how your pages will look. And another great thing about them is that style sheets make it really easy to update your pages when you want to make a new design. Simply load in a new style sheet onto your pages and you're done.
Alternate Style Sheet is a sheet defining an alternate style to be used in place of style(s) declared as persistent and/or preferred .
Persistent style is a default style that applies when style sheets are enabled but can disabled in favor of an alternate style, e.g.:
<LINK REL=Stylesheet HREF="style.css" TYPE="text/css">
Preferred style is a default style that applies automatically and is declared by setting the TITLE attribute to the LINK element. There can only be one preferred style, e.g.:
<LINK REL=Stylesheet HREF="style2.css" TYPE="text/css" TITLE="appropriate style description">
Alternate style gives an user the choice of selecting an alternative style - a very convenient way of specifying a media dependent style. Note: Each group of alternate styles must have unique TITLE, e.g.:
<LINK REL="Alternate Stylesheet" HREF="style3.css" TYPE="text/css" TITLE="appropriate style description" MEDIA=screen>
<LINK REL="Alternate Stylesheet" HREF="style4.css" TYPE="text/css" TITLE="appropriate style description" MEDIA=print>
Alternate stylesheet are not yet supported.
<!--[if gte IE 5]> <style type="text/css">
width:expression(documentElement.clientWidth < 780 ? (documentElement.clientWidth == 0 ? (body.clientWidth < 780 ? "780px" : "auto") : "780px") : "auto" );
As the property is non-standard, it won't validate with the W3C validator, so if we put it in the head like this (above) - in an IE conditional comment - the validator will ignore it and the page will get a clean bill of health.
It depends on your definition of "support." If you are interested in those browsers which makes some attempt at supporting CSS, no matter how partial or bug-ridden, then the list is:
* Internet Explorer 3.0 and above
* Navigator 4.0 and above
* Opera 3.6 and above
* XPublish by Media Design in·Progress
If instead you're interested in those browsers which are known to do a credible job of bug-free and mostly completel support for CSS1, then the list narrows somewhat dramatically:
* Internet Explorer 5.0 for Macintosh and above
* Internet Exporer 5.5 for Windows and above
* Netscape Navigator 6.0 and above
* Opera 4.0 and above
While none of these browser can be claimed to have a perfect implementation of CSS1, they are all quite good and can be relied upon to operate in a consistent fashion for most of CSS1.