The basic unit of CSS is a definition of a style property for a selected HTML tag
written in the following syntax:
html_tag_name{style_property_name:style_property_value}
For Example:
/* set background color to black for the <BODY> tag */
BODY {background-color: black}
/* set font size to 16pt for the <H1> tag */
H1 {font-size: 16pt}
/* set left margin to 0.5 inch for the <BLOCKQUOTE> tag */
BLOCKQUOTE {margin-left: 0.5in}
