Property Reference - CSS Reference - page 144

Name
border-right-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 right border of an element, which will take effect only if the border's
style is something other than none . If the border style is none , the border width is effectively
reset to 0 . Negative length values are not permitted.
Examples:
img {border-right-width: 30px;}
h3 {border-right-width: 1em;}