border-bottom

The border-bottom shorthand CSS property sets an element's bottom border. It sets the values of {{cssxref("border-bottom-width")}}, {{cssxref("border-bottom-style")}} and {{cssxref("border-bottom-color")}}.

{{InteractiveExample("CSS Demo: border-bottom")}}

border-bottom: solid;

border-bottom: dashed red;

border-bottom: 1rem solid;

border-bottom: thick double #32a1ce;

border-bottom: 4mm ridge rgb(211 220 50 / 0.6);

<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element">
    This is a box with a border around it.
  </div>
</section>

#example-element {
  background-color: #eeeeee;
  color: darkmagenta;
  padding: 0.75em;
  width: 80%;
  height: 100px;
}

Constituent properties

This property is a shorthand for the following CSS properties:

• {{cssxref("border-bottom-color")}}
• {{cssxref("border-bottom-style")}}
• {{cssxref("border-bottom-width")}}

Syntax

border-bottom: 1px;
border-bottom: 2px dotted;
border-bottom: medium dashed blue;

/* Global values */
border-bottom: inherit;
border-bottom: initial;
border-bottom: revert;
border-bottom: revert-layer;
border-bottom: unset;

The three values of the shorthand property can be specified in any order, and one or two of them may be omitted.

Values

• <br-width>
  • : See {{cssxref("border-bottom-width")}}.
• <br-style>
  • : See {{cssxref("border-bottom-style")}}.
• {{cssxref("<color>")}}
  • : See {{cssxref("border-bottom-color")}}.

Description

As with all shorthand properties, border-bottom always sets the values of all of the properties that it can set, even if they are not specified. It sets those that are not specified to their default values. Consider the following code:

border-bottom-style: dotted;
border-bottom: thick green;

It is actually the same as this one:

border-bottom-style: dotted;
border-bottom: none thick green;

The value of {{cssxref("border-bottom-style")}} given before border-bottom is ignored. Since the default value of {{cssxref("border-bottom-style")}} is none, not specifying the border-style part results in no border.

Formal definition

{{CSSInfo}}

Formal syntax

{{csssyntax}}

Examples

Applying a bottom border

HTML

<div>This box has a border on the bottom side.</div>

CSS

div {
  border-bottom: 4px dashed blue;
  background-color: gold;
  height: 100px;
  width: 100px;
  font-weight: bold;
  text-align: center;
}

Results

{{EmbedLiveSample('Applying_a_bottom_border')}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{cssxref("border")}}
• {{cssxref("border-block")}}
• {{cssxref("outline")}}