border-width

The border-width CSS property sets the width of the border of a box. Using the shorthand property border is often more convenient.

Values

<br-width>
Is either a non-negative explicit <length> value or a keyword denoting the thickness of the bottom border. The keyword must be one of the following values:

thin
A thin border
medium
A medium border
thick
A thick border

Example

<!DOCTYPE HTML>
<html>
    <head>
        <title>CSS Tutorials</title>
        <style>
            div {
                border: solid red;
				/* 2px wide top and bottom border, 10px right and left border */
                border-width: 2px 10px; 
            }
        </style>
    </head>
    <body>
        <div>
            Border-Width Demonstration 
        </div>
    </body>
</html>