CSS features: grouping

To reduce the syze of style sheets, you can group tags, declarations and properties. Tags are <h1>, <h2>, <p>, <br>, <div>, <font> and so on. In CSS documentation they are called 'selectors'. Let's see a simple CSS rule:

h1 {color : red}

h1 is the selector (i.e., the HTML tag <h1>)
{color : red} is a declaration
color is a property, and red is its value

So you can group tags (selectors), in this way (look at the comma that divide them):

h1, h2, h3 {color :red}

You can group declarations:

h1 {font-weight : bold; font-size : 12pt; font-family : elvetica; color : red}