CSS: Spacing and Areas : Page 11

It is illegal to use negative values for border-bottom-width. Different Web browsers interpret thin, medium, and thick differently, but the width of thin is always smaller than medium, which is always smaller than thick.

The border-bottom-width property should be used in conjunction with the border-style property to ensure that CSS-enabled browsers process it correctly.

Example:

	P {border-bottom-width: 2in}
	

If you are using a CSS-enabled browser, this paragraph has a 2-inch-wide bottom border.