The border-width property is used in CSS and certain HTML elements. This is a shorthand property which allows authors to specify the border-top-width, border-right-width, border-bottom-width, and border-left-width properties using a single property and value notation (the values are given in this order separated by spaces). If one or more of the values are not present, the value for a missing side is taken from the opposite side that is present. If only one value is listed, it applies to all sides.
Values[]
inherit- Explicitly sets the value of this property to that of the parent.thin,medium,thick- Renders a "thin", "medium" or "thick" border for a side of the element's rendering box. The actual thickness of these border values is not specified, but "thin" should have a smaller thickness than "medium", which should have a smaller thickness than "thick".<length>- Sets the width of the border for a side of the element's rendering box to an explicit measurement. Examples of lengths arepx,em, etc.
HTML example:
<h1 style="border-width:thick thin thick thin;"> H1 content. </h1>
CSS example:
h1 {
border-width:thick thin thick thin;
}