[1] [[manakai]] implements some proprietary extensions to [[CSS]].

[2] For [[Selectors]] extensions, see separate documentation: [[Selectors Extensions]].

* [CODE(CSS)[<color>]]

[17] The keyword [DFN[[CODE(CSS)@en['[[-manakai-default]]']]]] can be used as [CODE(CSS)@en[[[<color>]]]].
The keyword identifies the [[initial value]] of the [CODE(CSS)@en['[[color]]']] property.
The [[computed value]] of the keyword is the [[initial value]] of the [CODE(CSS)@en['[[color]]']] property,
represented in the same format as [[computed value]] of the RGB or RGBA value.

* [CODE(CSS)@en[<'outline-color'>]]

[16] The keyword [DFN[[CODE(CSS)@en['[[-manakai-invert-or-currentcolor]]']]]] can be used as
[CODE(CSS)@en[<'[[outline-color]]'>]].  The keyword represents [CODE(CSS)@en['[[invert]]']]
if that keyword is supported, or [CODE(CSS)@en['[[currentColor]]']] otherwise.
The [[computed value]] of the keyword is the [[computed value]] of [CODE(CSS)@en['[[invert]]']]
or [CODE(CSS)@en['[[currentColor]]']], respectively.

* [CODE(CSS)@en[<absolute-size>]]

[15] The keyword [DFN[[CODE(CSS)@en['[[-manakai-xxx-large]]']]]] [['''MUST''']] be replaced by
[CODE(CSS)@en['[[-webkit-xxx-large]]']] at parse time.

* [CODE(CSS)@en['border-spacing']]

[14] The [CODE(CSS)@en['[[-manakai-border-spacing-x]]']] property [['''MUST''']] be replaced by
[CODE(CSS)@en['[[-webkit-border-horizontal-spacing]]']] property at parse time.

[13] The [CODE(CSS)@en['[[-manakai-border-spacing-y]]']] property [['''MUST''']] be replaced by
[CODE(CSS)@en['[[-webkit-border-vertical-spacing]]']] property at parse time.

* [CODE(CSS)@en[<generic-family>]]

[12] The keyword [DFN[[CODE(CSS)@en['[[-manakai-default]]']]]] can be used as [CODE(CSS)@en[[[<geeric-family>]]]].
The keyword identifies the [[initial value]] of the [CODE(CSS)@en['[[font-family]]']] property.
The [[computed value]] of the keyword is the [[initial value]] of the [CODE(CSS)@en['[[font-family]]']] property.

[11] Following values are obsolete: [CODE(CSS)@en['[[-manakai-caption]]']], 
[CODE(CSS)@en['[[-manakai-icon]]']],
[CODE(CSS)@en['[[-manakai-menu]]']], and 
[CODE(CSS)@en['[[-manakai-message-box]]']].

* [CODE(CSS)@en[<'quotes'>]]

[10] The keyword [DFN[[CODE(CSS)@en['[[-manakai-default]]']]]] can be used as [CODE(CSS)@en[[[<'quotes'>]]]].
The keyword identifies the [[initial value]] of the [CODE(CSS)@en['[[quotes]]']] property.
The [[computed value]] of the keyword is the [[computed value]] of the [[initial value]] of the 
[CODE(CSS)@en['[[quotes]]']] property.

* Property extensions

[6] Properties [DFN@en['[CODE(CSS)@en[[[-manakai-border-spacing-x]]]]']] and
[DFN@en['[CODE(CSS)@en[[[-manakai-border-spacing-y]]]]']] work as longhand
properties for the standard '[CODE(CSS)@en[[[border-spacing]]]]' property [CSS21].

Allowed values for these properties are same as allowed values for
[CODE(CSS)@en[[[border-spacing]]]], except that only one value [['''MAY''']] be specified.

If '[CODE(CSS)@en[[[-manakai-border-spacing-x]]]]' property is specified, then
it [['''MUST''']] be interpreted as if the 
'[CODE(CSS)@en[[[border-spacing]]]]' property were specified with two values,
whose first value is the value specified to the
'[CODE(CSS)@en[[[-manakai-border-spacing-x]]]]' property, and whose second value
is the special value that represents the horizontal spacing length is left
unchanged.

If '[CODE(CSS)@en[[[-manakai-border-spacing-y]]]]' property is specified, then
it [['''MUST''']] be interpreted as if the 
'[CODE(CSS)@en[[[border-spacing]]]]' property were specified with two values,
whose first value
is the special value that represents the vertical spacing length is left
unchanged, and whose second value is the value specified to the
'[CODE(CSS)@en[[[-manakai-border-spacing-y]]]]' property.

The computed value of these properties are the first or the second value
of the computed value of the '[CODE(CSS)@en[[[border-spacing]]]]' property,
respectively.

Other characteristics of thse properties, such as whether inherited or not,
are same as those for the '[CODE(CSS)@en[[[border-spacing]]]]' property.

Attributes [CODE(DOMa)@en[[[ManakaiBorderSpacingX]]]] and 
[CODE(DOMa)@en[[[ManakaiBorderSpacingY]]]] on
the [CODE(DOMi)@en[[[CSSStyleDeclaration]]]] interface [CSSOM] [['''MUST''']] reflect these
properties, respectively.

* Property value extensions

[3] Keyword [DFN@en['[CODE(CSS)@en[[[-manakai-default]]]]']] [['''MAY''']] be used where
[CODE(CSS)@en[<[[color]]>]] is expected.  It represents the initial value of
the '[CODE(CSS)@en[[[color]]]]' property [CSS21].

;; The initial value of the '[CODE(CSS)@en[[[color]]]]' property is the user-specified
default color for texts.

The computed value of '[CODE(CSS)@en[[[-manakai-default]]]]' is itself.

[7] Keyword [DFN['[CODE(CSS)@en[[[-manakai-default]]]]']] [['''MAY''']] also be used
where [CODE(CSS)@en[<[[font-family]]>]] is expected.  It represents the intial value
of the '[CODE(CSS)@en[[[font-family]]]]' property [CSS21].

;; The initial value of the '[CODE(CSS)@en[[[-manakai-default]]]]' is  the 
user-defined default font family.

The computed value of '[CODE(CSS)@en[[[-manakai-default]]]]' is itself.

[9] Keyword [DFN['[CODE(CSS)@en[[[-manakai-default]]]]']] [['''MAY''']] also be used
where [CODE(CSS)@en[<'[[quotes]]'>]] is expected.  It represents the intial value
of the '[CODE(CSS)@en[[[quotes]]]]' property [CSS21].

;; The initial value of the '[CODE(CSS)@en[[[-manakai-default]]]]' is the
default quotation marks.

The computed value of '[CODE(CSS)@en[[[-manakai-default]]]]' is itself.

[4] Keyword [DFN@en['[CODE(CSS)@en[[[-manakai-invert-or-currentcolor]]]]']] 
[['''MAY''']] be used where [CODE(CSS)@en[<'[[outline-color]]'>]] is expected.  It represents
the initial value of the '[CODE(CSS)@en[[[outline-color]]]]' property [CSS21].

;; The initial value of the '[CODE(CSS)@en[[[outline-color]]]]' property is 
either '[CODE(CSS)@en[[[invert]]]]' or '[CODE(CSS)@en[[[currentColor]]]]',
depending on the environment.

The computed value of '[CODE(CSS)@en[[[-manakai-invert-or-currentcolor]]]]'
is '[CODE(CSS)@en[[[invert]]]]', if that keyword is supported, or same as
the computed value of the '[CODE(CSS)@en[[[color]]]]' property, otherwise.

[5] Keyword [DFN@en['[CODE(CSS)@en[[[-manakai-xxx-large]]]]'']] represents what
'[CODE(CSS)@en[[[-webkit-xxx-large]]]]' represents [WEBKIT].

@@ Should we deprecate this keyword and convert into '-webkit-xxx-large'
at parse time?

[8] Keywords [DFN@en['[CODE(CSS)@en[[[-manakai-caption]]]]']], 
[DFN@en['[CODE(CSS)@en[[[-manakai-icon]]]]']], 
[DFN@en['[CODE(CSS)@en[[[-manakai-menu]]]]']], 
[DFN@en['[CODE(CSS)@en[[[-manakai-message-box]]]]']], 
[DFN@en['[CODE(CSS)@en[[[-manakai-small-caption]]]]']], and
[DFN@en['[CODE(CSS)@en[[[-manakai-status-bar]]]]']] [['''MAY''']]
be used where [CODE(CSS)@en[<[[font-family]]>]] is expected.
These represent font families that would be used when CSS 2.1
system font keywords with similar names are specified.

Computed values of these keywords are same as themselves.

* References

[CSS21] CSS 2.1 Specification, latest version <http://www.w3.org/TR/CSS21/>.

[CSSOM] CSSOM Specification.

@@ [WEBKIT] Ref to WebKit extensions

* memo