outline-width
The outline-width CSS property is used to set the width of the outline of an element. An outline is a line that is drawn around elements, outside the border edge, to make the element stand out:
Syntax
outline-width: thin
outline-width: medium
outline-width: thick
outline-width: 1px /*
outline-width: 0.1em
outline-width: inherit
Example
<!DOCTYPE html> <html> <head> <style> div { outline-style:solid; outline-width:thick; } </style> </head> <body> <div> Sample Text </div> </body> </html>