Web Design with HTML and CSS

66

The role of CSS

Web Design with HTML and CSS Digital Classroom

The role of CSS

Cascading Style Sheets (CSS) use a separate language from HTML. CSS allows you to apply

consistent styling of elements across all pages on your site, so that all headings, lists, and

paragraphs look and act the same on every page of a site.

How we refer to CSS syntax in this book

Before you begin to work with CSS, we need to explain how we will refer to the various

parts of CSS syntax throughout this book. This is not as easy as it sounds because there is a gap

between the offi cial specifi cation of the CSS language and the way designers often refer to CSS

in the “real world.” Nevertheless, here are the fundamentals: all the following code is what we

refer to as a rule in CSS:

h1 {

color:blue;

margin-top:1em;

}

There are various components to this rule, as follows:

K^

FRORUEOXH

PDUJLQWRSHP¦

`

A

C

B

D

A. Selector. B. Declaration. C. Property. D.Value.

We will refer to each of the various components from time to time throughout the book, so if

we ask you to change the value “blue” to “red” you should know what to do. Or if we ask you

to locate and change the h1 selector to a h2 selector, it should make sense.

On a day-to-day basis, most designers aren’t always so specifi c however. For example the rule

above might be referred to as a “style,” “style rule,” “the h1 rule,” or “the CSS rule for h1.” Also,

as you can see above, the offi cial name for the pair of the property and the value is called a

declaration. Again, in everyday use, the use of the term “declaration” is not common and most

designers will use the term property or properties interchangeably.