CSS border-spacing

<!doctype html>
<title>Example</title>
<style>
table {
  border: 1px solid blue;
  border-collapse: separate;
  border-spacing: 30px 10px;
  }
td {
  border: 1px solid red;
  }
</style>
<table>
  <tr>
    <td>This table is styled using the CSS border-spacing property. Note that two values were provided - one for horizontal border-spacing and one for vertical border-spacing. </td>
    <td>Try changing the value to see the effect it has on the border.</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
</table>

The CSS border-spacing property allows you to specify the amount of space between borders of adjoining cell borders in tables.

By default, an HTML table uses the "separated borders model". This results in a kind of "double border" effect where there's space between the borders of each cell, as well as the edge of the table (if you also have a border on the table element).

You can use the border-spacing property to specify the amount of space between each cell border.

Syntax

Possible Values

length

Specifies the distance that separates adjoining cell borders in separated-borders mode.

If one length is provided, it sets both the horizontal and vertical spacing. If two lengths are provided, the first sets the horizontal spacing and the second the vertical spacing.

In addition, all CSS properties also accept the following CSS-wide keyword values as the sole component of their property value:

initial: Represents the value specified as the property's initial value.
inherit: Represents the computed value of the property on the element's parent.
unset: This value acts as either inherit or initial, depending on whether the property is inherited or not. In other words, it sets all properties to their parent value if they are inheritable or to their initial value if not inheritable.

General Information

Initial Value: 0
Applies To: Table-root boxes (tables or inline-table boxes) when border-collapse is separate.
Inherited?: Yes
Media: Visual
Animatable: Yes (see example)

Example Code

Official Specifications

CSS Table Module Level 3 (W3C First Public Working Draft, 25 October 2016)
CSS Level 2.1 (W3C Recommendation 07 June 2011)