What are the three primary parts of a CSS definition?

Answer 1

The three primary parts of a CSS definition are:

selector{property:value;}

The selector can be one of three things or a combination of the three. These are element (such as <div> or <img />), id (#), and class (.).

The property can be a number of rules ('background', color, font-weight). A good place to reference these is w3schools.org.

The value is specific to the property. For example, if the selector is 'color', value could be 'red' or '#ccc', but it couldn't be 'bold'.

Answer 2

The three parts to a CSS rule statement are the selector, the property, and the value. Here is are several examples of CSS rules.

h1 { color: #FFCC00; }

.tv-show { color: #3984BD; }

#copyright { color: #9CBDDE; }

Each of these examples contain all three parts of a CSS rule statement. In this example, the selector is h1, .tv-show, and #copyright. The h1 selector targets all level 1 headings, the .tv-show is a class selector that applies everytime the class="tv-show" is used in HTML, and the #copyright is an ID selector that applies to the unique identifier id="copyright" in an HTML document.

In all three cases, I used the same CSS property, the color property to alter the color. The final part is the value. In each of the three cases I used a hexadecimal color value as the value for the color property.

You'll notice that in each of my CSS rule statements that the property and value are separated by a colon (:) and that after the value I have a semi-colon (;). The colon separating the property and the value is required. The use of the semi-colon is recommended when you have a single rule defined, but if you have multiple rule declarations in a single declaration block then it is required. Finally, you'll also notice that my property/value pairs are located inside a set of curly brackets ( { } ). This is also required syntax when declaring CSS rules in external or embedded style sheets.