Shorthand properties

Shorthand properties are CSS properties that let you set the values of multiple other CSS properties simultaneously. Using a shorthand property, you can write more concise (and often more readable) style sheets, saving time and energy.

The CSS specification defines shorthand properties to group the definition of common properties acting on the same theme. For instance, the CSSbackground property is a shorthand property that's able to define the values ofbackground-color,background-image,background-repeat, andbackground-position. Similarly, the most common font-related properties can be defined using the shorthandfont, and the different margins around a box can be defined using themargin shorthand.

Tricky edge cases

There are a few edge cases to keep in mind when using shorthand properties.

Omitting properties

A value which is not specified is set to its initial value. That means that itoverrides previously set values. For example:

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p {  background-color: red;  background: url("images/bg.gif") no-repeat left top;}

This will not set the color of the background tored but to the default value forbackground-color, which istransparent.

Only the individual properties values can inherit. As missing values are replaced by their initial value, it is impossible to allow inheritance of individual properties by omitting them. The keywordinherit can be applied to a property, but only as a whole, not as a keyword for one value or another. That means that the only way to make some specific value to be inherited is to use the longhand property with the keywordinherit.

Ordering properties

Shorthand properties try not to force a specific order for the values of the properties they replace. This works well when these properties use values of different types, as the order has no importance, but this does not work as easily when several properties can have identical values.

Two important cases here are:

properties related to the edges of a box, likeborder-style,margin orpadding
properties related to the corners of a box, likeborder-radius

Edges of a box

Shorthands handling properties related to edges of a box, likeborder-style,margin orpadding, always use a consistent 1-to-4-value syntax representing those edges:

1-value syntax:border-width: 1em — The single value represents all edges:
2-value syntax:border-width: 1em 2em — The first value represents the vertical, that is top and bottom, edges, the second the horizontal ones, that is the left and right ones:
3-value syntax:border-width: 1em 2em 3em — The first value represents the top edge, the second, the horizontal, that is left and right, ones, and the third value the bottom edge:
4-value syntax:border-width: 1em 2em 3em 4em — The four values represent the top, right, bottom and left edges respectively, always in that order, that is clock-wise starting at the top: The initial letter of Top-Right-Bottom-Left matches the order of the consonant of the wordtrouble: TRBL. You can also remember it as the order that the hands would rotate on a clock:1em starts in the 12 o'clock position, then2em in the 3 o'clock position, then3em in the 6 o'clock position, and4em in the 9 o'clock position.

Corners of a box

Similarly, shorthands handling properties related to corners of a box, likeborder-radius, always use a consistent 1-to-4-value syntax representing those corners:

1-value syntax:border-radius: 1em — The single value represents all corners:
2-value syntax:border-radius: 1em 2em — The first value represents the top left and bottom right corner, the second the top right and bottom left ones:
3-value syntax:border-radius: 1em 2em 3em — The first value represents the top left corner, the second the top right and bottom left ones, and the third value the bottom right corner:
4-value syntax:border-radius: 1em 2em 3em 4em — The four values represent the top left, top right, bottom right and bottom left corners respectively, always in that order, that is clock-wise starting at the top left:

Background properties

Consider a background with the following properties

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background-color: black;background-image: url("images/bg.gif");background-repeat: no-repeat;background-position: left top;

These four declarations can be shortened to just one:

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background: black url("images/bg.gif") no-repeat left top;

(The shorthand form is actually the equivalent of the longhand properties above plusbackground-attachment: scroll and, in CSS3, some additional properties.)

Seebackground for more detailed information, including CSS3 properties.

Font properties

Consider the following declarations:

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font-style: italic;font-weight: bold;font-size: 0.8em;line-height: 1.2;font-family: "Arial", sans-serif;

These 5 statements can be shortened to the following:

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font:  italic bold 0.8em/1.2 "Arial",  sans-serif;

This shorthand declaration is actually equivalent to the longhand declarations above plusfont-variant: normal,font-size-adjust: none, andfont-stretch: normal.

Border properties

With borders, the width, color, and style can be simplified into one declaration. For example, consider the following CSS:

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border-width: 1px;border-style: solid;border-color: black;

It can be simplified as:

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border: 1px solid black;

Margin and padding properties

Shorthand versions of margin and padding values work similarly; the margin property allows for shorthand values to be specified using one, two, three, or four values. Consider the following CSS declarations:

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margin-top: 10px;margin-right: 5px;margin-bottom: 10px;margin-left: 5px;

They are the same as the following declaration using the four value shorthand. Note that the values are in clockwise order, beginning at the top: top, right, bottom, then left (TRBL, the consonants in "trouble").

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margin: 10px 5px 10px 5px;

Margin shorthand rules for one, two, three and four value declarations are:

Whenone value is specified, it applies the same margin toall four sides.
Whentwo values are specified, the first margin applies to thetop and bottom, the second to theleft and right.
Whenthree values are specified, the first margin applies to thetop, the second to theleft and right, the third to thebottom.
Whenfour values are specified, the margins apply to thetop,right,bottom, andleft in that order (clockwise).

Position properties

With position, the shorthand versions of top, right, bottom and left can be simplified into one declaration. For example, consider the following CSS:

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top: 0;right: 20px;bottom: 0;left: 20px;

It can be simplified as:

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inset: 0 20px 0 20px;

Just like margins and paddings, the inset values are ordered clockwise - top, right, bottom, then left (TRBL).

The universal shorthand property

CSS provides a universal shorthand property,all, which applies its value to every property in the document. Its purpose is to change the properties' inheritance model.

SeeHandling conflicts orIntroducing the CSS Cascade for more information about how inheritance works in CSS.