CSS is usually used by creating a stylesheet file and linking your XHTML code to that file. The stylesheet file will contain a list of rules, and selectors which define what parts of the XHTML code the rules apply to. To begin, create a new blank text file, save it with a
.css file extension, and store it in your
www directory. Now you will need to add a special XHTML tag (shown below) somewhere in the head section of any webpages which will use your CSS styles. This tag links your webpage to your stylesheet.
<link href="style.css" rel="stylesheet" type="text/css" />
Make sure that you’ve put this tag in the head section of your webpage (not the body section), and that the value of the
hrefattribute contains a path to the CSS file you’ve just created. Repeat this for any pages you want to style with your CSS file. You can also use multiple stylesheets on the same webpage. Be careful, though. If you have conflicting styles, only one of the styles will be used.
The stylesheet is organized into “blocks” of CSS rules. Each block is composed of a selector, followed by a list of rules enclosed with curly braces (
}). A CSS selector is a way of defining the scope of the rules; in other words, a selector defines to which elements the rules will be applied. The example below shows the generic syntax of a stylesheet.
/* this is a block of CSS rules */
/* this is another block */
Note: In CSS, lines that begin with
/* and end with
*/ are comments. Just like XHTML comments, they have no impact on the webpage; they are only displayed in the code and are meant to add documentation or any other notes to the code.