Learning Web Design, 5th Edition

14. Thinking Inside the Box

14

Thinking Inside the Box

In this chapter

The parts of an element box

Setting box dimensions

Padding

Borders

Outlines

Margins

Assigning display roles

Adding a drop shadow

In Chapter 11, Introducing Cascading Style Sheets I described the box model as one of the fundamental concepts of CSS. According to the box model, every element in a document generates a box to which properties such as width, height, padding, borders, and margins can be applied. You probably already have a feel for how element boxes work from adding backgrounds to elements. This chapter covers all the box-related properties, beginning with an overview of the components of an element box, and then taking on the box properties from the inside out: content dimensions, padding, borders, and margins.

The Element Box

As we’ve seen, every element in a document, both block-level and inline, generates a rectangular element box. The components of an element box are diagrammed in Figure 14-1. Pay attention to the new terminology—it will be helpful in keeping things straight later in the chapter.

Figure 14-1. The parts of an element box according to the CSS box model.

Content area

At the core of the element box is the content itself. In Figure 14-1, the content area is indicated by a white box.

Inner edges

The edges of the content area are referred to as the inner edges of the element ...