Beginning CSS: Cascading Style Sheets for Web Design, 2nd ...

11PositioningThis chapter examines the various properties that CSS provides to position elements in a document.Positioning can be thought of as layering, in that the various elements of a page can be layeredon top of others and given specific places to appear in the browser’s window. In this chapterI discuss:❑❑❑❑The position property and the four types of positioning that CSS has to offer: static,relative, absolute, and fixedThe offset properties top, right, bottom, and left, and how these are used to deliver anelement to a specific position in a web documentThe z-index property and how this property is used to layer the elements of a documentSome practical applications of positioning, such as multicolumn layouts and verticallycentering a positioned elementPositioning makes CSS a very powerful presentational language, and further enhances its flexibility.Like floating elements, positioning offers some unique characteristics that allow behavior youmight not always expect. This chapter begins the discussion of positioning with none other thanthe position property.