Copyright © 2013 W3C® (MIT, ERCIM, Keio, Beihang), All Rights Reserved. W3C liability, trademark and document use rules apply.
This module contains the features of CSS relating to the alignment of boxes within their containers in the various CSS box layout models: block layout, table layout, flex layout, and grid layout. (The alignment of text and inline-level content is defined in [CSS3TEXT] and [CSS3LINE].) CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, in speech, etc.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
The (archived) public mailing list www-style@w3.org (see instructions) is preferred for discussion of this specification. When sending e-mail, please put the text “css3-align” in the subject, preferably like this: “[css3-align] …summary of comment…”
This document was produced by the CSS Working Group (part of the Style Activity).
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
The following features are at risk: …
center
’, ‘stretch
’, ‘start
’,
‘end
’, ‘self-start
’, ‘self-end
’,
‘flex-start
’, ‘flex-end
’, ‘left
’, and
‘right
’ keywords
baseline
’ keyword
space-between
’,
‘space-around
’, and ‘space-evenly
’ keywords
safe
’ and ‘true
’ keywords
justify-content
’ and
‘align-content
’ properties
This section is not normative.
CSS Levels 1 and 2 allowed for the alignment of text via ‘text-align
’ and the alignment of blocks by
balancing ‘auto
’ margins. However, except in
table cells, vertical alignment was not possible. As CSS3 adds further
capabilities, the ability to align boxes in various dimensions becomes
more critical. This module attempts to create a cohesive and common box
alignment model to share among all of CSS.
The alignment of text and inline-level content is defined in [CSS3TEXT] and [CSS3LINE].
Inspiration for this document:
This module adds some new alignment capabilities to the block layout
model described in [CSS21] chapters 9 and 10 and defines
the interaction of these properties with the alignment of table cell
content using ‘vertical-align
’, as defined
in [CSS21] chapter
17. The interaction of these properties with Grid Layout [CSS3-GRID-LAYOUT] and
Flexible Box Layout [CSS3-FLEXBOX] is defined in
their respective modules.
No properties in this module apply to the ::first-line
or
::first-letter
pseudo-elements.
This specification follows the CSS property
definition conventions from [CSS21]. Value types not defined in
this specification are defined in CSS Level 2 Revision 1 [CSS21]. Other CSS
modules may expand the definitions of these value types: for example [CSS3VAL], when
combined with this module, adds the ‘initial
’
keyword as a possible property value.
In addition to the property-specific values listed in their definitions, all properties defined in this specification also accept the inherit keyword as their property value. For readability it has not been repeated explicitly.
The alignment properties in CSS can be described along two axes:
This proposal uses the terms ‘justify
’ and ‘align
’ to distinguish between alignment in the
inline and stacking dimensions, respectively. The choice is somewhat
arbitrary, but having the two terms allows for a consistent naming scheme
that works across all of CSS's layout models.
The following table summarizes the proposed alignment properties and the display types they can apply to.
Common | Axis | Aligns | Applies to |
---|---|---|---|
‘justify-content ’
| inline | content within element (effectively adjusts padding) | block containers and flex containers |
‘align-content ’
| stacking | block containers and flex containers | |
‘justify-self ’
| inline | element within parent (effectively adjusts margins) | block-level elements and grid items |
‘align-self ’
| stacking | flex items and grid items | |
‘justify-items ’
| inline | items inside element (controls child items’
‘align/justify-self: auto ’)
| grid containers |
‘align-items ’
| stacking | flex containers and grid containers |
The exact definition of these properties outside what's what's defined in Flexbox is still being worked out. This is a second Working Draft and is NOT STABLE.
The ‘-items
’ values don't
affect the element itself. When set on a flex container or grid container,
they specify the interpretation of any ‘align/justify-self: auto
’ used on the items in the
container element.
All of the alignment properties use a common set of values, defined below.
justify-self
’ and
‘align-self
’,
the alignment subject is the
margin box of the box the property is set on. For ‘justify-content
’ and ‘align-content
’,
the alignment subject is defined
by the layout mode.
center
’,
‘stretch
’, ‘start
’, ‘end
’, ‘self-start
’, ‘self-end
’, ‘flex-start
’, ‘flex-end
’, ‘left
’, and ‘right
’ keywordsThe positional alignment keywords specify a position for an alignment subject with respect to its alignment container.
The <item-position> set of
values is used by ‘justify-self
’ and ‘align-self
’ to align
the box within its alignment
container, and also by ‘justify/align-items
’ (to specify default values for
‘justify/align-self
’). The <content-position> set of
values is used by ‘justify-content
’ and ‘align-content
’ to
align the box's contents within itself.
<item-position> = center | start | end | self-start | self-end | flex-start | flex-end | left | right; <content-position> = center | start | end | flex-start | flex-end | left | right;
Values have the following meanings:
center
’
stretch
’
width
’ or ‘height
’ (as appropriate) of the alignment subject is ‘auto
’, its used value is the length necessary to make
the alignment subject’s outer
size as close to the size of the alignment container as possible,
while still respecting the constraints imposed by ‘min/max-width/height
’. Otherwise, this is equivalent
to ‘start
’.
start
’
end
’
self-start
’
self-end
’
flex-start
’
start
’.
flex-end
’
start
’.
left
’
start
’.
right
’
start
’.
Add example images.
baseline
’ keywordBaseline alignment is a form of positional alignment that relies on aligning the baselines of related alignment subjects to each other.
baseline
’
For table cells, grid items, and flex items, aligns the cell/item's
first formatted line's baseline, if any, with the same
baseline in other ‘baseline
’-aligned cells/items in the row/column
(as appropriate for the axis).
In the case of ‘align-content
’/‘justify-content
’, this shifts the content of
the box within it, and may also affect its sizing. In the case of ‘align-self
’/‘justify-self
’
this shifts the entire box within its container, and may affect the
sizing of its container.
If the alignment subject’s position is not fully determined by baseline alignment, the content is start-aligned insofar as possible while preserving the baseline alignment. (Content that has no first-line baseline is thus start-aligned.)
Add example images.
The baseline of a box is determined differently based on the layout model, as follow:
block
’
list-item
’
The inline-axis baseline of a block is the baseline of the first
in-flow line box in the block, or the first in-flow block-level child in
the block that has a baseline, whichever comes first. If there is no
such line box or child, then the block has no baseline. For the purposes
of finding a baseline, in-flow boxes with a scrolling mechanisms (see
the ‘overflow
’ property) must be
considered as if scrolled to their origin position.
A block has no block-axis baseline.
table
’
The inline-axis baseline of a table box is the baseline of its first row. However, when calculating the baseline of an inline-block, table boxes must be skipped.
The block-axis baseline of a table is undefined.
Or does it have no baseline? Or is it based on its first column?
table-row
’
If any cells in the row participate in its baseline alignment, the inline-axis baseline of the row is their baseline, after baseline alignment has been performed. Otherwise, the inline-axis baseline of the row is the bottom content edge of the lowest cell in the row. [CSS21]
A table row has no block-axis baseline.
table-cell
’
The inline-axis baseline of a table cell is the baseline of the first in-flow line box in the cell, or the first in-flow element that contributes a baseline in that axis, whichever comes first.
A table cell has no block-axis baseline.
flex
’
grid
’
Maybe these things are wrong? CSS 2.1 is really weird about baseline alignment. This whole section needs to be better defined and reviewed.
space-between
’, ‘space-around
’, and ‘space-evenly
’ keywordsThe distribution values are used by ‘justify-content
’ and ‘align-content
’ to
distribute the items in the alignment
subject evenly between the start and end edges of the alignment container. When the alignment subject cannot be
distributed in this way, they behave as their fallback alignment. Each distribution value
has an associated <content-position> as a fallback alignment, but one can
alternatively be explicitly specified in the property.
<content-distribution> = space-between | space-around | space-evenly | stretch
space-between
’
start
’.
space-around
’
center
’.
space-evenly
’
center
’.
stretch
’
auto
’-sized items have their size increased equally so
that the combined size exactly fills the alignment container. Otherwise, or
if there are no ‘auto
’-sized items, this value
is identical to ‘flex-start
’. (For layout modes
other than flex layout, ‘flex-start
’ is identical to ‘start
’.)
Add example images.
safe
’ and ‘true
’ keywordsWhen the alignment subject is larger than the alignment container, it will overflow. Some alignment modes, if honored in this situation, may cause data loss: for example, if the contents of a sidebar are centered, when they overflow they may send part of their boxes past the viewport's start edge, which can't be scrolled to.
To help combat this problem, an overflow alignment mode can be explicitly specified. "True" alignment honors the specified alignment mode in overflow situations, even if it causes data loss, while "safe" alignment changes the alignment mode in overflow situations in an attempt to avoid data loss.
If the overflow alignment isn't explicitly specified, the default overflow alignment is determined by the layout mode. Document-centric layout modes, such as block layout, default to "safe" overflow alignment, while design-centric layout modes, such as flex layout, default to "true" overflow alignment.
<overflow-position> = true | safe
safe
’
start
’.
true
’
Transplant example 10 from flexbox.
justify-content
’ and ‘align-content
’
propertiesThe ‘justify-content
’ and ‘align-content
’
properties control alignment of the box's content within the box.
Name: | justify-content, align-content |
---|---|
Value: | auto | baseline | [ <content-distribution> <content-position>? | <content-position> ] && <overflow-position>? |
Initial: | auto |
Applies to: | block containers, flex containers, and grid containers |
Inherited: | no |
Percentages: | N/A |
Media: | visual |
Computed value: | specified value |
Animatable: | no |
Canonical order: | per grammar |
Aligns the contents of the box as a whole along the box's
inline/row/main axis. Values other than ‘auto
’
are defined above. If both a <content-distribution>
and <content-position> are
given, the second value represents an explicit fallback alignment.
The alignment container is the block container’s content box. The alignment subject is the entire contents of the block.
The ‘align-content
’ property applies along the
block axis, but if a <content-distribution>
is specified the fallback
alignment is used instead. The ‘justify-content
’ property does not apply to
and has no effect on block containers.
All values other than ‘auto
’ force the
block container to establish a new formatting context. For table cells,
the behavior of the ‘auto
’ depends on the
computed value of ‘vertical-align
’:
‘top
’ makes it behave as ‘start
’, ‘middle
’ makes it behave as ‘center
’, ‘bottom
’
makes it behave as ‘end
’,
and all other values make it behave as ‘baseline
’. ‘auto
’
otherwise behaves as ‘start
’.
The alignment container is the multi-column element’s content box. The alignment subject is the column boxes, as a unit.
The ‘align-content
’ property applies along the
block axis, but if a <content-distribution>
is specified the fallback
alignment is used instead. The ‘justify-content
’ property does not apply to
and has no effect on multi-column elements.
‘auto
’ behaves as ‘start
’.
‘auto
’ computes to ‘stretch
’.
The alignment container is
the flex container’s content box. For ‘justify-content
’, the alignment subject is the flex
items in each flex line; for ‘align-content
’,
the alignment subject is the
flex lines.
The ‘align-content
’ property applies along the
cross axis. The ‘justify-content
’ property applies along the
main axis, but ‘stretch
’ behaves as ‘start
’.
See [CSS3-FLEXBOX] for details.
‘auto
’ computes to ‘start
’, and ‘stretch
’ behaves like
‘start
’.
The alignment container is the grid container’s content box. The alignment subject is the bounds of the grid. Need to dfn a better term for this in Grid.
The ‘align-content
’ property applies along the
block (column) axis. The ‘justify-content
’ property applies along the
inline (row) axis. In both properties, if a <content-distribution>
is specified, the fallback
alignment is used instead.
The content of boxes participating in row-like layout contexts can be baseline-aligned to each other. The alignment subject of a box participating in baseline content-alignment is shifted such that the baseline of the first formatted line of all participating boxes align, and the intrinsic size of each box is increased by the distance the content needed to shift in order to thus align the baselines.
The set of boxes that participate in baseline content-alignment together depends on the layout model:
align-content
’ is ‘baseline
’.
align-content
’ is ‘baseline
’, its computed
‘align-self
’ is
‘stretch
’ or ‘start
’, and its inline
axis is parallel to the main axis.
align-content
’ is ‘baseline
’, and its
computed ‘align-self
’ or ‘justify-self
’
(whichever affects its block axis) is ‘stretch
’ or ‘start
’.
If a cell/item spans multiple rows or columns, it participates in alignment within its start-most row/column only.
The ‘justify-self
’ and ‘align-self
’
properties control alignment of the box within its containing block.
justify-self
’ propertyName: | justify-self |
---|---|
Value: | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] |
Initial: | auto |
Applies to: | block-level boxes, absolutely-positioned boxes, and grid items |
Inherited: | no |
Percentages: | N/A |
Media: | visual |
Computed value: | specified value |
Animatable: | no |
Canonical order: | per grammar |
Justifies the box within its parent along the inline/row/main axis: the box's outer edges are aligned within its alignment container as described by its alignment value.
The ‘auto
’ keyword computes to ‘stretch
’ on
absolutely-positioned elements, and to the computed value of ‘justify-items
’ on
the parent (minus any ‘legacy
’ keywords) on all other boxes.
The ‘justify-self
’ property applies along its
containing block's inline axis.
The alignment container is
the block's containing block except that for block-level elements that
establish a block formatting context and are placed next to a float, the
alignment container is reduced
by the space taken up by the float. (Note: This is the legacy behavior
of HTML align
.) The alignment subject is the block's
margin box.
The default overflow
alignment is ‘safe
’. In terms of CSS2.1 block-level formatting
[CSS21], the rules
for "over-constrained" computations in section
10.3.3 are ignored in favor of alignment as specified here and the
used value of the offset properties are not adjusted to correct for the
over-constraint.
The ‘stretch
’
value is equivalent to ‘start
’ on block-level boxes.
This property does not apply to floats.
The ‘justify-self
’ property applies along its
containing block's inline axis.
When neither margin in this dimension is ‘auto
’ and neither offset property in this dimension
is ‘auto
’, values other than ‘stretch
’ cause non-replaced
absolutely-positioned boxes to use shrink-to-fit sizing for
calculating ‘auto
’ measures, and ‘justify-self
’
dictates alignment as follows:
The alignment container is
the box's containing block as modified by the offset properties
(‘top
’/‘right
’/‘bottom
’/‘left
’). The alignment subject is the box's
margin box.
The default overflow
alignment is ‘safe
’. In terms of CSS2.1 formatting [CSS21], the rules
for "over-constrained" computations in section
10.3.7 are ignored in favor of alignment as specified here and the
used value of the offset properties are not adjusted to correct for the
over-constraint.
The ‘stretch
’
keyword is equivalent to ‘start
’ on replaced absolutely-positioned boxes.
(This is because CSS 2.1 does not stretch replaced elements to fit into
fixed offsets.)
This property does not apply to table cells, because their position and size is fully constrained by table layout.
This property does not apply to flex items, because there is
more than one item in the main axis. See ‘flex
’ for stretching and ‘justify-content
’ for main-axis
alignment. [CSS3-FLEXBOX]
The ‘justify-self
’ property applies along the
grid's row axis.
The alignment container is
the grid cell. The alignment
subject is the grid item’s margin box. The default overflow alignment is ‘true
’.
Should we make ‘stretch
’ actually work on block-level/abspos
replaced boxes? To maintain legacy compat, this requires adding a new
value (named ‘normal
’?) which has the current
behavior of stretching non-replaced boxes and start-aligning replaced
ones.
The effect of these rules is that an auto-sized block-level table, for example, can be aligned while still having side margins. If the table's max-content size is narrower than its containing block, then it is shrink-wrapped to that size and aligned as specified. If the table's max-content size is wider, then it fills its containing block, and the margins provide appropriate spacing from the containing block edges.
align-self
’ propertyName: | align-self |
---|---|
Value: | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] |
Initial: | auto |
Applies to: | block-level elements |
Inherited: | no |
Percentages: | N/A |
Media: | visual |
Computed value: | specified value |
Animatable: | no |
Canonical order: | per grammar |
Aligns the box within its parent along the block/column/cross axis: the box's outer edges are aligned within its alignment container as described by its alignment value.
The ‘auto
’ keyword computes to ‘stretch
’ on
absolutely-positioned elements, and to the computed value of ‘justify-items
’ on
the parent (minus any ‘legacy
’ keywords) on all other boxes.
The ‘align-self
’ property does not apply to
block-level boxes (including floats), because there is more than one
item in the block axis.
The ‘justify-self
’ property applies along its
containing block's inline axis.
When neither margin in this dimension is ‘auto
’ and neither offset property in this dimension
is ‘auto
’, values other than ‘stretch
’ cause non-replaced
absolutely-positioned boxes to use shrink-to-fit sizing for
calculating ‘auto
’ measures, and ‘align-self
’
dictates alignment as follows:
The alignment container is
the box's containing block as modified by the offset properties
(‘top
’/‘right
’/‘bottom
’/‘left
’). The alignment subject is the box's
margin box.
The default overflow
alignment is ‘safe
’. In terms of CSS2.1 formatting [CSS21], the rules
for "over-constrained" computations in section
10.6.4 are ignored in favor of alignment as specified here and the
used value of the offset properties are not adjusted to correct for the
over-constraint.
The ‘stretch
’
keyword is equivalent to ‘start
’ on replaced absolutely-positioned boxes.
(This is because CSS 2.1 does not stretch replaced elements to fit into
fixed offsets.)
This property does not apply to table cells, because their position and size is fully constrained by table layout.
The ‘align-self
’ property applies along the
flexbox's cross axis.
The alignment container is
the flex line the item is in. The alignment subject is the flex
item’s margin box. The default overflow alignment is ‘true
’. See [CSS3-FLEXBOX] for details.
The ‘align-self
’ property applies along the
grid's column axis.
The alignment container is
the grid cell. The alignment
subject is the grid item’s margin box. The default overflow alignment is ‘true
’.
Boxes participating in row-like layout contexts can be baseline-aligned to each other. An alignment subject participating in baseline content-alignment is shifted such that the baseline of the first formatted line of all participating boxes align, and the intrinsic size of its alignment container is increased by the largest distance a box needed to shift in order to thus align the baselines.
The set of boxes that participate in baseline self-alignment together depends on the layout model:
justify-self
’ or ‘align-self
’ property
(whichever matches its inline axis) computes to ‘baseline
’.
If a cell/item spans multiple rows or columns, it participates in alignment within its start-most row/column only.
The ‘align-items
’ and ‘justify-items
’
properties set the default ‘align-self
’ and ‘justify-self
’
behavior of the items contained by the element.
justify-items
’ propertyName: | justify-items |
---|---|
Value: | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] | [ legacy && [ left | right | center ] ] |
Initial: | auto |
Applies to: | block containers, flex containers, and grid containers |
Inherited: | no |
Percentages: | N/A |
Media: | visual |
Computed value: | specified value |
Animatable: | no |
Canonical order: | per grammar |
This property specifies the default ‘justify-self
’ for all of the boxes (including
anonymous boxes) participating in this box's formatting context. Values
have the following meanings:
auto
’
If the element has a parent, and its computed value for ‘justify-items
’
includes the ‘legacy
’
keyword, ‘auto
’ computes to the parent's
value.
Otherwise, ‘auto
’ computes to:
legacy
’
center
’, ‘left
’, and ‘right
’ positions. The alignment keyword, but not
the ‘legacy
’ keyword, is
passed to ‘justify-self
’. It exists to implement the
legacy alignment behavior of HTML's <center>
element and
align
attribute.
Other values have no special handling and are merely passed to ‘justify-self
’.
align-items
’ propertyName: | align-items |
---|---|
Value: | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] |
Initial: | auto |
Applies to: | block-level elements |
Inherited: | no |
Percentages: | N/A |
Media: | visual |
Computed value: | specified value |
Animatable: | no |
Canonical order: | per grammar |
This property specifies the default ‘align-self
’ for all of the boxes (including
anonymous boxes) participating in this box's formatting context. Values
have the following meanings:
Other values have no special handling and are merely passed to ‘align-self
’.
Changes since the First Public Working Draft include:
safe
’ and
‘true
’ as overflow alignment keywords and made the
default layout-mode-dependent.
head
’ and ‘foot
’ keywords, defined ‘start
’ and ‘end
’ keywords as relative to the alignment container‘s writing mode, and added
’‘self-start
’‘ and
’‘self-end
’‘ to be relative
to the alignment subject.
<CENTER>>
/align
attribute requirements by
adding ‘legacy
’ keyword.
justify-content
’ and ‘align-content
’.
Conformance requirements are expressed with a combination of descriptive assertions and RFC 2119 terminology. The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this document are to be interpreted as described in RFC 2119. However, for readability, these words do not appear in all uppercase letters in this specification.
All of the text of this specification is normative except sections explicitly marked as non-normative, examples, and notes. [RFC2119]
Examples in this specification are introduced with the words “for
example” or are set apart from the normative text with
class="example"
, like this:
This is an example of an informative example.
Informative notes begin with the word “Note” and are set apart from
the normative text with class="note"
, like this:
Note, this is an informative note.
Conformance to CSS Box Alignment Module Level 3 is defined for three conformance classes:
A style sheet is conformant to CSS Box Alignment Module Level 3 if all of its statements that use syntax defined in this module are valid according to the generic CSS grammar and the individual grammars of each feature defined in this module.
A renderer is conformant to CSS Box Alignment Module Level 3 if, in addition to interpreting the style sheet as defined by the appropriate specifications, it supports all the features defined by CSS Box Alignment Module Level 3 by parsing them correctly and rendering the document accordingly. However, the inability of a UA to correctly render a document due to limitations of the device does not make the UA non-conformant. (For example, a UA is not required to render color on a monochrome monitor.)
An authoring tool is conformant to CSS Box Alignment Module Level 3 if it writes style sheets that are syntactically correct according to the generic CSS grammar and the individual grammars of each feature in this module, and meet all other conformance requirements of style sheets as described in this module.
So that authors can exploit the forward-compatible parsing rules to assign fallback values, CSS renderers must treat as invalid (and ignore as appropriate) any at-rules, properties, property values, keywords, and other syntactic constructs for which they have no usable level of support. In particular, user agents must not selectively ignore unsupported component values and honor supported values in a single multi-value property declaration: if any value is considered invalid (as unsupported values must be), CSS requires that the entire declaration be ignored.
To avoid clashes with future CSS features, the CSS2.1 specification reserves a prefixed syntax for proprietary and experimental extensions to CSS.
Prior to a specification reaching the Candidate Recommendation stage in the W3C process, all implementations of a CSS feature are considered experimental. The CSS Working Group recommends that implementations use a vendor-prefixed syntax for such features, including those in W3C Working Drafts. This avoids incompatibilities with future changes in the draft.
Once a specification reaches the Candidate Recommendation stage, non-experimental implementations are possible, and implementors should release an unprefixed implementation of any CR-level feature they can demonstrate to be correctly implemented according to spec.
To establish and maintain the interoperability of CSS across implementations, the CSS Working Group requests that non-experimental CSS renderers submit an implementation report (and, if necessary, the testcases used for that implementation report) to the W3C before releasing an unprefixed implementation of any CSS features. Testcases submitted to W3C are subject to review and correction by the CSS Working Group.
Further information on submitting testcases and implementation reports can be found from on the CSS Working Group's website at http://www.w3.org/Style/CSS/Test/. Questions should be directed to the public-css-testsuite@w3.org mailing list.
[Change or remove the following CR exit criteria if the spec is not a module, but, e.g., a Note or a profile. This text was decided on 2008-06-04.]
For this specification to be advanced to Proposed Recommendation, there must be at least two independent, interoperable implementations of each feature. Each feature may be implemented by a different set of products, there is no requirement that all features be implemented by a single product. For the purposes of this criterion, we define the following terms:
The specification will remain Candidate Recommendation for at least six months.
Special thanks goes to Markus Mielke, Alex Mogilevsky, and the participants in the CSSWG's March 2008 F2F alignment discussions.
baseline
’, 3.2.
center
’, 3.1.
end
’, 3.1.
flex-end
’, 3.1.
flex-start
’, 3.1.
left
’, 3.1.
legacy
’, 6.1.
right
’, 3.1.
safe
’, 3.4.
self-end
’, 3.1.
self-start
’, 3.1.
space-around
’, 3.3.
space-between
’, 3.3.
space-evenly
’, 3.3.
start
’, 3.1.
stretch
’, 3.1., 3.3.
true
’, 3.4.
Property | Values | Initial | Applies to | Inh. | Percentages | Media |
---|---|---|---|---|---|---|
align-content | auto | baseline | [ <content-distribution> <content-position>? | <content-position> ] && <overflow-position>? | auto | block containers, flex containers, and grid containers | no | N/A | visual |
align-items | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] | auto | block-level elements | no | N/A | visual |
align-self | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] | auto | block-level elements | no | N/A | visual |
justify-content | auto | baseline | [ <content-distribution> <content-position>? | <content-position> ] && <overflow-position>? | auto | block containers, flex containers, and grid containers | no | N/A | visual |
justify-items | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] | [ legacy && [ left | right | center ] ] | auto | block containers, flex containers, and grid containers | no | N/A | visual |
justify-self | auto | stretch | baseline | [ <item-position> && <overflow-position>? ] | auto | block-level boxes, absolutely-positioned boxes, and grid items | no | N/A | visual |