Dreamweaver CS4 Resources

About CSS page layout structure

Before proceeding with this section, you should be familiar with basic CSS concepts.

The basic building block of the CSS layout is the div tag—an HTML tag that in most cases acts as a container for text, images, and other page elements. The following example shows an HTML page that contains three separate div tags: one large “container” tag, and two other tags—a sidebar tag, and a main content tag—within the container tag.

View full size graphic

A.: Container div
B.: Sidebar div
C.: Main Content div

Following is the code for all three div tags in the HTML:

<!--container div tag--> 
<div id="container"> 
<!--sidebar div tag--> 
    <div id="sidebar"> 
    <h3>Sidebar Content</h3> 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p> 
    <p>Maecenas urna purus, fermentum id, molestie in, commodo  porttitor, felis.</p> 
      </div> 
     
<!--mainContent div tag--> 
    <div id="mainContent"> 
    <h1> Main Content </h1> 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Praesent aliquam,  justo convallis luctus rutrum.</p> 
    <p>Phasellus tristique purus a augue condimentum adipiscing. Aenean  sagittis. Etiam leo pede, rhoncus venenatis, tristique in, vulputate at, odio.</p> 
    <h2>H2 level heading </h2> 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Praesent aliquam,  justo convallis luctus rutrum, erat nulla fermentum diam, at nonummy quam  ante ac quam.</p> 
    </div> 
</div>

In the above example, there is no “styling” attached to any of the div tags. Without CSS rules defined, each div tag and its contents fall into a default location on the page. However, if each div tag has a unique id (as in the above example), you can use the ids to create CSS rules that, when applied, change the style and positioning of the div tags.

The following CSS rule, which can reside in the head of the document or in an external CSS file, creates styling rules for the first, or “container” div tag on the page:

#container { 
    width: 780px; 
    background: #FFFFFF; 
    margin: 0 auto; 
    border: 1px solid #000000; 
    text-align: left; 
}

The #container rule styles the container div tag to have a width of 780 pixels, a white background, no margin (from the left side of the page), a solid, black, 1‑pixel border, and text that is aligned left. The results of applying the rule to the container div tag are as follows:

View full size graphic

Container div tag, 780 pixels, no margin

A.: Text aligned left
B.: White background
C.: 1-pixel solid black border

The next CSS rule creates styling rules for the sidebar div tag:

#sidebar { 
    float: left; 
    width: 200px; 
    background: #EBEBEB; 
    padding: 15px 10px 15px 20px; 
}

The #sidebar rule styles the sidebar div tag to have a width of 200 pixels, a gray background, a top and bottom padding of 15 pixels, a right padding of 10 pixels, and a left padding of 20 pixels. (The default order for padding is top-right-bottom-left.) Additionally, the rule positions the sidebar div tag with float: left—a property that pushes the sidebar div tag to the left side of the container div tag. The results of applying the rule to the sidebar div tag are as follows:

View full size graphic

Sidebar div, float left

A.: Width 200 pixels
B.: Top and bottom padding, 15 pixels

Lastly, the CSS rule for the main container div tag finishes the layout:

#mainContent { 
    margin: 0 0 0 250px; 
    padding: 0 20px 20px 20px; 
}

The #mainContent rule styles the main content div with a left margin of 250 pixels, which means that it places 250 pixels of space between the left side of the container div, and the left side of the main content div. Additionally, the rule provides for 20 pixels of spacing on the right, bottom, and left sides of the main content div. The results of applying the rule to the mainContent div are as follows:

View full size graphic

Main Content div, left margin of 250 pixels

A.: 20 pixels left padding
B.: 20 pixels right padding
C.: 20 pixels bottom padding

The complete code looks as follows:

<head> 
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> 
<title>Untitled Document</title> 
<style type="text/css"> 
#container { 
    width: 780px; 
    background: #FFFFFF; 
    margin: 0 auto; 
    border: 1px solid #000000; 
    text-align: left; 
} 
#sidebar { 
    float: left; 
    width: 200px; 
    background: #EBEBEB; 
    padding: 15px 10px 15px 20px; 
} 
#mainContent { 
    margin: 0 0 0 250px; 
    padding: 0 20px 20px 20px; 
} 
</style> 
</head> 
<body> 
<!--container div tag--> 
<div id="container"> 
    <!--sidebar div tag--> 
    <div id="sidebar"> 
    <h3>Sidebar Content</h3> 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p> 
    <p>Maecenas urna purus, fermentum id, molestie in, commodo  porttitor, felis.</p> 
      </div> 
     <!--mainContent div tag--> 
    <div id="mainContent"> 
    <h1> Main Content </h1> 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Praesent aliquam,  justo convallis luctus rutrum.</p> 
    <p>Phasellus tristique purus a augue condimentum adipiscing. Aenean  sagittis. Etiam leo pede, rhoncus venenatis, tristique in, vulputate at, odio.</p> 
    <h2>H2 level heading </h2> 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Praesent aliquam,  justo convallis luctus rutrum, erat nulla fermentum diam, at nonummy quam  ante ac quam.</p> 
    </div> 
</div> 
</body>

Note: The above example code is a simplified version of the code that creates the two-column fixed left sidebar layout when you create a new document using the predesigned layouts that come with Dreamweaver.