Property Reference - CSS Reference - page 123

Name
border-bottom-width
Values:
thin | medium | thick | <length>
Initial value:
medium
Applies to:
All elements
Inherited:
No
Computed value:
Absolute length; 0 if the style of the border is none or hidden
Description:
Defines the width for the bottom border of an element, which will take effect only if the bor-
der's style is something other than none . If the border style is none , the border width is effect-
ively reset to 0 . Negative length values are not permitted.
Examples:
ul {border-bottom-width: 0.5in;}
a:active {border-bottom-width: 2px;}