Cascading Style Sheets, or CSS, is a language used to specify the visual appearance of a Web page—in contrast to HTML (HyperText Markup Language), which is a markup language that defines the structure of a document for distribution on the Web. HTML tells a Web browser how the content is organized on the page, whereas CSS tells the browser how it should look. CSS3, an abbreviation for CSS Level 3, is the next generation of this style language that adds several new capabilities.

The margin of an element allows you to set the space between that element and other elements in the window by specifying one to four values that correspond to all four sides together, the top/ bottom and left/right sides as pairs, or all four sides independently. To define the margins of an element: 1. Start your declaration by typing the margin shortcut property name in the declaration block, followed by a colon (:) margin: 2. Type a value for the margin.

Setting the Table layout Different browsers use different methods to calculate how a particular table should be displayed. Two primary table-layout. Fixed method bases its layout on the width of the table and the width of columns in the first row. This method is generally faster than automatic.  Automatic uses the table column width along with the amount of content in the table data cell to calculate the table data cell width. This will generally render more slowly than the fixed method, but it also produces more accurate results for widths throughout the table.