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<!DOCTYPE html><html lang=en><head>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
<title>CSS Box Alignment Module Level 3</title>
<link href=../default.css rel=stylesheet type=text/css>
<link href=../csslogo.ico rel="shortcut icon" type=image/x-icon>
<style>
body {
background: url("https://www.w3.org/StyleSheets/TR/logo-ED") top left no-repeat white;
background-attachment: fixed;
color: black;
font-family: sans-serif;
margin: 0 auto;
max-width: 50em;
padding: 2em 1em 2em 70px;
}
:link { color: #00C; background: transparent }
:visited { color: #609; background: transparent }
a[href]:active { color: #C00; background: transparent }
a[href]:hover { background: #ffa }
a[href] img { border-style: none }
h1, h2, h3, h4, h5, h6 { text-align: left }
h1, h2, h3 { color: #005A9C; }
h1 { font: 170% sans-serif }
h2 { font: 140% sans-serif }
h3 { font: 120% sans-serif }
h4 { font: bold 100% sans-serif }
h5 { font: italic 100% sans-serif }
h6 { font: small-caps 100% sans-serif }
.hide { display: none }
div.head { margin-bottom: 1em }
div.head h1 { margin-top: 2em; clear: both }
div.head table { margin-left: 2em; margin-top: 2em }
p.copyright { font-size: small }
p.copyright small { font-size: small }
pre { margin-left: 2em }
dt { font-weight: bold }
ul.toc, ol.toc {
list-style: none;
}
</style>
<style type=text/css>
.issue th:first-child { text-align: left !important; }
[rowspan] > img { float: right; }
[rowspan] { vertical-align: middle; }
small { display: block; }
</style>
</head>
<body class=h-entry>
<div class=head>
<p data-fill-with=logo><a class=logo href=http://www.w3.org/>
<img alt=W3C height=48 src=http://www.w3.org/Icons/w3c_home width=72>
</a>
</p>
<h1 class="p-name no-ref" id=title>CSS Box Alignment Module Level 3</h1>
<h2 class="no-num no-toc no-ref heading settled heading" id=subtitle><span class=content>Editor’s Draft,
<span class=dt-updated><span class=value-title title=20140519>19 May 2014</span></span></span></h2>
<div data-fill-with=spec-metadata><dl><dt>This version:<dd><a class=u-url href=http://dev.w3.org/csswg/css-align/>http://dev.w3.org/csswg/css-align/</a><dt>Latest version:<dd><a href=http://www.w3.org/TR/css3-align/>http://www.w3.org/TR/css3-align/</a><dt>Editor’s Draft:<dd><a href=http://dev.w3.org/csswg/css-align/>http://dev.w3.org/csswg/css-align/</a><dt>Previ
8
ous Vers
10BC8
ions:<dd><a href=http://www.w3.org/TR/2013/WD-css3-align-20130514/ rel=previous>http://www.w3.org/TR/2013/WD-css3-align-20130514/</a><dd><a href=http://www.w3.org/TR/2012/WD-css3-align-20120612/ rel=previous>http://www.w3.org/TR/2012/WD-css3-align-20120612/</a>
<dt>Feedback:</dt>
<dd><a href="mailto:www-style@w3.org?subject=%5Bcss-align%5D%20feedback">www-style@w3.org</a>
with subject line
“<kbd>[css-align] <var>… message topic …</var></kbd>”(<a href=http://lists.w3.org/Archives/Public/www-style/ rel=discussion>archives</a>)<dt>Test Suite:<dd>None Yet<dt>Editors:
<dd class="p-author h-card vcard"><a class="p-name fn u-url url" href=http://fantasai.inkedblade.net/contact>fantasai</a> (<span class="p-org org">Invited Expert</span>)<dd class="p-author h-card vcard"><a class="p-name fn u-url url" href=http://xanthir.com/contact/>Tab Atkins Jr.</a> (<span class="p-org org">Google</span>)<dt>Issue Tracking:<dd><a href=http://www.w3.org/Style/CSS/Tracker/products/39>http://www.w3.org/Style/CSS/Tracker/products/39</a></dl></div>
<div data-fill-with=warning></div>
<p class=copyright data-fill-with=copyright><a href=http://www.w3.org/Consortium/Legal/ipr-notice#Copyright>Copyright</a> © 2014 <a href=http://www.w3.org/><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href=http://www.csail.mit.edu/><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href=http://www.ercim.eu/><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href=http://www.keio.ac.jp/>Keio</a>, <a href=http://ev.buaa.edu.cn/>Beihang</a>), All Rights Reserved. W3C <a href=http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer>liability</a>, <a href=http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks>trademark</a> and <a href=http://www.w3.org/Consortium/Legal/copyright-documents>document use</a> rules apply.
</p>
<hr title="Separator for header">
</div>
<h2 class="no-num no-toc no-ref heading settled heading" id=abstract><span class=content>Abstract</span></h2>
<p class=p-summary data-fill-with=abstract>This module contains the features of <a href=http://www.w3.org/TR/CSS/>CSS</a> 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 <a data-biblio-type=informative data-link-type=biblio href=#css3text title=css3text>[CSS3TEXT]</a> and <a data-biblio-type=informative data-link-type=biblio href=#css3line title=css3line>[CSS3LINE]</a>.)
<a href=http://www.w3.org/TR/CSS/>CSS</a> is a language for describing the rendering of structured documents
(such as HTML and XML)
on screen, on paper, in speech, etc.</p>
<h2 class="no-num no-toc no-ref heading settled heading" id=status><span class=content>Status of this document</span></h2>
<div data-fill-with=status><p>
This is a public copy of the editors’ draft.
It is provided for discussion only and may change at any moment.
Its publication here does not imply endorsement of its contents by W3C.
Don’t cite this document other than as work in progress.
<p>
The (<a href=http://lists.w3.org/Archives/Public/www-style/>archived</a>) public mailing list
<a href="mailto:www-style@w3.org?Subject=%5Bcss-align%5D%20PUT%20SUBJECT%20HERE">www-style@w3.org</a>
(see <a href=http://www.w3.org/Mail/Request>instructions</a>)
is preferred for discussion of this specification.
When sending e-mail,
please put the text “css-align” in the subject,
preferably like this:
“[css-align] <em>…summary of comment…</em>”
<p>
This document was produced by the <a href=http://www.w3.org/Style/CSS/members>CSS Working Group</a>
(part of the <a href=http://www.w3.org/Style/>Style Activity</a>).
<p>
This document was produced by a group operating under
the <a href=http://www.w3.org/Consortium/Patent-Policy-20040205/>5 February 2004 W3C Patent Policy</a>.
W3C maintains a <a href=http://www.w3.org/2004/01/pp-impl/32061/status rel=disclosure>public list of any patent disclosures</a>
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 <a href=http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential>Essential Claim(s)</a>
must disclose the information in accordance with <a href=http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure>section 6 of the W3C Patent Policy</a>.</div>
<div data-fill-with=at-risk><p>The following features are at-risk, and may be dropped during the CR period:
<ul><li><a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a></ul></div>
<h2 class="no-num no-toc no-ref heading settled heading" id=contents><span class=content>Table of Contents</span></h2>
<div data-fill-with=table-of-contents><ul class=toc>
<li><a href=#intro><span class=secno>1</span> Introduction</a>
<ul class=toc>
<li><a href=#placement><span class=secno>1.1</span> Module interactions</a>
<li><a href=#values><span class=secno>1.2</span> Values</a></ul>
<li><a href=#overview><span class=secno>2</span> Overview of Alignment Properties</a>
<li><a href=#alignment-values><span class=secno>3</span> Alignment Values</a>
<ul class=toc>
<li><a href=#positional-values><span class=secno>3.1</span> Positional Alignment: the <span class=css data-link-type=maybe title=center>center</span>, <span class=css data-link-type=maybe title=stretch>stretch</span>, <span class=css data-link-type=maybe title=start>start</span>, <span class=css data-link-type=maybe title=end>end</span>, <span class=css data-link-type=maybe title=self-start>self-start</span>, <span class=css data-link-type=maybe title=self-end>self-end</span>, <span class=css data-link-type=maybe title=flex-start>flex-start</span>, <span class=css data-link-type=maybe title=flex-end>flex-end</span>, <span class=css data-link-type=maybe title=left>left</span>, and <span class=css data-link-type=maybe title=right>right</span> keywords</a>
<li><a href=#baseline><span class=secno>3.2</span> Baseline Alignment: the <span class=css data-link-type=maybe title=baseline>baseline</span> and <span class=css data-link-type=maybe title=last-baseline>last-baseline</span> keywords</a>
<li><a href=#distribution-values><span class=secno>3.3</span> Distributed Alignment: the <span class=css data-link-type=maybe title=space-between>space-between</span>, <span class=css data-link-type=maybe title=space-around>space-around</span>, and <span class=css data-link-type=maybe title=space-evenly>space-evenly</span> keywords</a>
<li><a href=#overflow-values><span class=secno>3.4</span> Overflow Alignment: the <span class=css data-link-type=maybe title=safe>safe</span> and <span class=css data-link-type=maybe title=true>true</span> keywords</a></ul>
<li><a href=#content-distribution><span class=secno>4</span> Content Distribution: the <span class=property data-link-type=propdesc title=justify-content>justify-content</span> and <span class=property data-link-type=propdesc title=align-content>align-content</span> properties</a>
<ul class=toc>
<li><a href=#baseline-align-content><span class=secno>4.1</span> Baseline Content-Alignment</a></ul>
<li><a href=#self-alignment><span class=secno>5</span> Self-Alignment: Aligning the Box within its Parent</a>
<ul class=toc>
<li><a href=#justify-self-property><span class=secno>5.1</span> Inline/Main-Axis Alignment: the <span class=property data-link-type=propdesc title=justify-self>justify-self</span> property</a>
<li><a href=#align-self-property><span class=secno>5.2</span> Block/Cross-Axis Alignment: the <span class=property data-link-type=propdesc title=align-self>align-self</span> property</a>
<li><a href=#baseline-align-self><span class=secno>5.3</span> Baseline Self-Alignment</a></ul>
<li><a href=#default-alignment><span class=secno>6</span> Default Alignment</a>
<ul class=toc>
<li><a href=#justify-items-property><span class=secno>6.1</span> Inline/Main-Axis Alignment: the <span class=property data-link-type=propdesc title=justify-items>justify-items</span> property</a>
<li><a href=#align-items-property><span class=secno>6.2</span> Block/Cross-Axis Alignment: the <span class=property data-link-type=propdesc title=align-items>align-items</span> property</a></ul>
<li><a href=#baseline-rules><span class=secno>7</span> Determining the Baseline of a Box</a>
<li><a href=#changes><span class=secno>8</span> Changes</a>
<li><a href=#acknowledgments><span class=secno></span> Acknowledgments</a>
<li><a href=#conformance><span class=secno></span> Conformance</a>
<ul class=toc>
<li><a href=#conventions><span class=secno></span> Document conventions</a>
<li><a href=#conformance-classes><span class=secno></span> Conformance classes</a>
<li><a href=#partial><span class=secno></span> Partial implementations</a>
<li><a href=#experimental><span class=secno></span> Experimental implementations</a>
<li><a href=#testing><span class=secno></span> Non-experimental implementations</a></ul>
<li><a href=#references><span class=secno></span> References</a>
<ul class=toc>
<li><a href=#normative><span class=secno></span> Normative References</a>
<li><a href=#informative><span class=secno></span> Informative References</a></ul>
<li><a href=#index><span class=secno></span> Index</a>
<li><a href=#property-index><span class=secno></span> Property index</a>
<li><a href=#issues-index><span class=secno></span>Issues Index</a></ul></div>
<h2 class="heading settled heading" data-level=1 id=intro><span class=secno>1 </span><span class=content>
Introduction</span><a class=self-link href=#intro></a></h2>
<p><em>This section is not normative.</em></p>
<p>CSS Levels 1 and 2 allowed for the alignment of text via <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-text-3/#propdef-text-align title=text-align>text-align</a> and
the alignment of blocks by balancing <span class=css data-link-for=margin data-link-type=maybe title=auto>auto</span> 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.</p>
<p class=note>Note: The alignment of text and inline-level content is defined in <a data-biblio-type=informative data-link-type=biblio href=#css3text title=css3text>[CSS3TEXT]</a> and <a data-biblio-type=informative data-link-type=biblio href=#css3line title=css3line>[CSS3LINE]</a>.</p>
<p>Inspiration for this document:</p>
<ul>
<li><a href=http://wiki.csswg.org/ideas/centering#alignment-property>summary of a discussion for implementing <CENTER></a>
<li><a href=https://lists.w3.org/Archives/Member/w3c-css-wg/2008AprJun/0015.html>Minutes from March 2008 F2F</a>
<li><a href=http://lists.w3.org/Archives/Public/www-style/2012Feb/0743.html>fantasai’s attempt to merge all alignment properties</a>
</ul>
<h3 class="heading settled heading" data-level=1.1 id=placement><span class=secno>1.1 </span><span class=content>
Module interactions</span><a class=self-link href=#placement></a></h3>
<p>This module adds some new alignment capabilities to the block layout
model described in <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a> chapters 9 and 10 and defines the interaction
of these properties with the alignment of table cell content using
<a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visudet.html#propdef-vertical-align title=vertical-align>vertical-align</a>, as defined in <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a> chapter 17.
The interaction of these properties with
Grid Layout <a data-biblio-type=normative data-link-type=biblio href=#css3-grid-layout title=css3-grid-layout>[CSS3-GRID-LAYOUT]</a>
and Flexible Box Layout <a data-biblio-type=normative data-link-type=biblio href=#css3-flexbox title=css3-flexbox>[CSS3-FLEXBOX]</a>
is defined in their respective modules.</p>
No properties in this module apply to the <code>::first-line</code> or
<code>::first-letter</code> pseudo-elements.
<h3 class="heading settled heading" data-level=1.2 id=values><span class=secno>1.2 </span><span class=content>
Values</span><a class=self-link href=#values></a></h3>
<p>This specification follows the
<a href=http://www.w3.org/TR/CSS21/about.html#property-defs>CSS property
definition conventions</a> from <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a>. Value types not defined in
this specification are defined in CSS Level 2 Revision 1 <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a>.
Other CSS modules may expand the definitions of these value types: for
example <a data-biblio-type=informative data-link-type=biblio href=#css3val title=css3val>[CSS3VAL]</a>, when combined with this module, adds the
<span class=css data-link-type=maybe title=initial>initial</span> keyword as a possible property value.</p>
<p>In addition to the property-specific values listed in their definitions,
all properties defined in this specification also accept the
<a href=http://www.w3.org/TR/CSS21/cascade.html#value-def-inherit>inherit</a>
keyword as their property value. For readability it has not been repeated
explicitly.</p>
<h2 class="heading settled heading" data-level=2 id=overview><span class=secno>2 </span><span class=content>
Overview of Alignment Properties</span><a class=self-link href=#overview></a></h2>
<p>The alignment properties in CSS can be described along two axes:</p>
<ul>
<li>which dimension they apply to (inline vs. stacking), and
<li>whether they control the position of the box within its parent, or the box’s content within itself.
</ul>
<p class=note>Note: 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.</p>
<p>The following table summarizes the proposed alignment properties
and the display types they can apply to.</p>
<table class=data>
<colgroup span=1></colgroup>
<colgroup span=2></colgroup>
<colgroup span=1></colgroup>
<thead>
<tr>
<th>Common
<th>Axis
<th>Aligns
<th>Applies to
</thead>
<tbody>
<tr>
<th><a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a>
<td>inline
<td rowspan=2>
<img alt="" height=106 src=images/content-example.svg width=106>
content within element
<small>(effectively adjusts padding)</small>
<td>block containers and flex containers
<tr>
<th><a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a>
<td>stacking
<td>block containers and flex containers
<tbody>
<tr>
<th><a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a>
<td>inline
<td rowspan=2>
<img alt="" height=106 src=images/self-example.svg width=106>
element within parent
<small>(effectively adjusts margins)</small>
<td>block-level elements and grid items
<tr>
<th><a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a>
<td>stacking
<td>flex items and grid items
<tbody>
<tr>
<th><a class=property data-link-type=propdesc href=#propdef-justify-items title=justify-items>justify-items</a>
<td>inline
<td rowspan=2>
<img alt="" height=106 src=images/items-example.svg width=106>
items inside element
<small>(controls child items’ <span class=css data-link-type=maybe title="align/justify-self: auto">align/justify-self: auto</span>)</small>
<td>grid containers
<tr>
<th><a class=property data-link-type=propdesc href=#propdef-align-items title=align-items>align-items</a>
<td>stacking
<td>flex containers and grid containers
</table>
<p class=issue id=issue-1ad5b2aa><a class=self-link href=#issue-1ad5b2aa></a>
The exact definition of these properties
outside what’s <a href=http://www.w3.org/TR/css3-flexbox>what’s defined in Flexbox</a>
is still <strong>being worked out</strong>.
This is a <strong>second Working Draft</strong>
and is <strong>NOT STABLE</strong>.
<p class=note>Note: The <a class=property data-link-type=propdesc title=*-items>*-items</a> values don’t affect the element itself.
When set on a flex container or grid container,
they specify the interpretation of any <span class=css data-link-type=maybe title="align/justify-self: auto">align/justify-self: auto</span> used on the items in the container element.</p>
<h2 class="heading settled heading" data-level=3 id=alignment-values><span class=secno>3 </span><span class=content>
Alignment Values</span><a class=self-link href=#alignment-values></a></h2>
<p>All of the alignment properties use a common set of values,
defined below.</p>
<dl>
<dt><dfn data-dfn-type=dfn data-export="" id=alignment-subject>alignment subject<a class=self-link href=#alignment-subject></a></dfn>
<dd>
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the thing or things being aligned by the property.
For <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> and <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a>,
the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the margin box of the box the property is set on.
For <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> and <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a>,
the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is defined by the layout mode.
<dt><dfn data-dfn-type=dfn data-export="" id=alignment-container>alignment container<a class=self-link href=#alignment-container></a></dfn>
<dd>
The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the rectangle that the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is aligned within.
This is defined by the layout mode,
but is usually the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>’s containing block.
</dl>
<h3 class="heading settled heading" data-level=3.1 id=positional-values><span class=secno>3.1 </span><span class=content>
Positional Alignment: the <a class=css data-link-type=maybe href=#valuedef-center title=center>center</a>, <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a>, <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>, <a class=css data-link-type=maybe href=#valuedef-end title=end>end</a>, <a class=css data-link-type=maybe href=#valuedef-self-start title=self-start>self-start</a>, <a class=css data-link-type=maybe href=#valuedef-self-end title=self-end>self-end</a>, <a class=css data-link-type=maybe href=#valuedef-flex-start title=flex-start>flex-start</a>, <a class=css data-link-type=maybe href=#valuedef-flex-end title=flex-end>flex-end</a>, <a class=css data-link-type=maybe href=#valuedef-left title=left>left</a>, and <a class=css data-link-type=maybe href=#valuedef-right title=right>right</a> keywords</span><a class=self-link href=#positional-values></a></h3>
<p>The positional alignment keywords specify a position for an <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>
with respect to its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>.</p>
<p>The <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> set of values is used by <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> and <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a>
to align the box within its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
and also by <a class=property data-link-type=propdesc href=#propdef-justify-items title=justify-items>justify-items</a> and <a class=property data-link-type=propdesc href=#propdef-align-items title=align-items>align-items</a>
(to specify default values for <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> and <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a>).
The <a class="production css-code" data-link-type=type href=#typedef-content-position title="<content-position>"><content-position></a> set of values is used by <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> and <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a>
to align the box’s contents within itself.</p>
<pre class=prod> <dfn class=css-code data-dfn-type=type data-export="" id=typedef-item-position><item-position><a class=self-link href=#typedef-item-position></a></dfn> = center | start | end | self-start | self-end |
flex-start | flex-end | left | right;
<dfn class=css-code data-dfn-type=type data-export="" id=typedef-content-position><content-position><a class=self-link href=#typedef-content-position></a></dfn> = center | start | end | flex-start | flex-end | left | right;
</pre>
<p>Values have the following meanings:</p>
<dl data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-center>center<a class=self-link href=#valuedef-center></a></dfn>
<dd>Centers the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> within its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>.
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-start>start<a class=self-link href=#valuedef-start></a></dfn>
<dd>Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>’s start edge.
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-end>end<a class=self-link href=#valuedef-end></a></dfn>
<dd>Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>’s end edge.
<dt><dfn class=css-code data-dfn-for="<item-position>" data-dfn-type=value data-export="" id=valuedef-self-start>self-start<a class=self-link href=#valuedef-self-start></a></dfn>
<dd>Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the edge of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
corresponding to the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>’s start side.
If the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#writing-mode0 title="writing modes">writing modes</a> of the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> and the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> are <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#establish-an-orthogonal-flow- title=orthogonal>orthogonal</a>,
this value computes to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
<dt><dfn class=css-code data-dfn-for="<item-position>" data-dfn-type=value data-export="" id=valuedef-self-end>self-end<a class=self-link href=#valuedef-self-end></a></dfn>
<dd>Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the edge of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
corresponding to the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>’s end side.
If the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#writing-mode0 title="writing modes">writing modes</a> of the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> and the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> are <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#establish-an-orthogonal-flow- title=orthogonal>orthogonal</a>,
this value computes to <a class=css data-link-type=maybe href=#valuedef-end title=end>end</a>.
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-flex-start>flex-start<a class=self-link href=#valuedef-flex-start></a></dfn>
<dd><strong>Only used in flex layout.</strong> <a data-biblio-type=normative data-link-type=biblio href=#css3-flexbox title=css3-flexbox>[CSS3-FLEXBOX]</a>
Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the edge of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
corresponding to the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-container title="flex container">flex container</a>’s main-start or cross-start side, as appropriate.
When used in layout modes other than Flexbox,
this value computes to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-flex-end>flex-end<a class=self-link href=#valuedef-flex-end></a></dfn>
<dd><strong>Only used in flex layout.</strong>
Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the edge of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
corresponding to the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-container title="flex container">flex container</a>’s main-end or cross-end side, as appropriate.
When used in layout modes other than Flexbox,
this value computes to <a class=css data-link-type=maybe href=#valuedef-end title=end>end</a>.
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-left>left<a class=self-link href=#valuedef-left></a></dfn>
<dd>Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>’s <a href=http://www.w3.org/TR/css3-writing-modes/#line-left>line-left</a> edge.
If the property’s axis is not parallel with the inline axis,
this value computes to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
<dt><dfn class=css-code data-dfn-for="<item-position>, <content-position>" data-dfn-type=value data-export="" id=valuedef-right>right<a class=self-link href=#valuedef-right></a></dfn>
<dd>Aligns the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> to be flush with the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>’s <a href=http://www.w3.org/TR/css3-writing-modes/#line-right>line-right</a> edge.
If the property’s axis is not parallel with the inline axis,
this value computes to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
</dl>
<p class=issue id=issue-511afb430><a class=self-link href=#issue-511afb430></a>
Add example images.
<h3 class="heading settled heading" data-level=3.2 id=baseline><span class=secno>3.2 </span><span class=content>
Baseline Alignment: the <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> and <a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a> keywords</span><a class=self-link href=#baseline></a></h3>
<p><dfn data-dfn-type=dfn data-noexport="" id=baseline-alignment>Baseline alignment<a class=self-link href=#baseline-alignment></a></dfn> is a form of positional alignment
that aligns multiple <a data-link-type=dfn href=#alignment-subject title="alignment subjects">alignment subjects</a> within a <a data-link-type=dfn href=#shared-alignment-context title="shared alignment context">shared alignment context</a> (such as cells within a row or column)
by matching up their <a data-link-type=dfn href=#alignment-baseline title="alignment baselines">alignment baselines</a>.</p>
<p>The baseline alignment keywords are:</p>
<pre class=prod> <dfn class=css-code data-dfn-type=type data-export="" id=typedef-baseline-position><baseline-position><a class=self-link href=#typedef-baseline-position></a></dfn> = baseline | last-baseline
</pre>
<p>and are defined below:</p>
<dl data-dfn-for="justify-content, justify-self, justify-items, align-content, align-self, align-items" data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for="justify-content, justify-self, justify-items, align-content, align-self, align-items" data-dfn-type=value data-export="" id=valuedef-baseline>baseline<a class=self-link href=#valuedef-baseline></a></dfn>
<dd>
Indicates <dfn class=css-code data-dfn-for="justify-content, justify-self, justify-items, align-content, align-self, align-items" data-dfn-type=value data-export="" id=valuedef-first-baseline-alignment>first-baseline alignment<a class=self-link href=#valuedef-first-baseline-alignment></a></dfn>:
aligns one of the box’s <a data-link-type=dfn href=#first-baselines title="first baselines">first baselines</a>
with the corresponding <a data-link-type=dfn href=#first-baselines title="first baselines">first baselines</a>
of all the boxes in its <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">baseline-sharing group</a>.
<p>If the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>’s position is not fully determined by <a data-link-type=dfn href=#baseline-alignment title="baseline alignment">baseline alignment</a>,
the content is <a class=css data-link-type=maybe href=#valuedef-self-start title=self-start>self-start</a>-aligned insofar as possible while preserving the baseline alignment.
(Content that has no <a data-link-type=dfn href=#first-baselines title="first baselines">first baselines</a> is thus start-aligned.)</p>
<dt><dfn class=css-code data-dfn-for="justify-content, justify-self, justify-items, align-content, align-self, align-items" data-dfn-type=value data-export="" id=valuedef-last-baseline>last-baseline<a class=self-link href=#valuedef-last-baseline></a></dfn>
<dd>
Indicates <dfn class=css-code data-dfn-for="justify-content, justify-self, justify-items, align-content, align-self, align-items" data-dfn-type=value data-export="" id=valuedef-last-baseline-alignment>last-baseline alignment<a class=self-link href=#valuedef-last-baseline-alignment></a></dfn>:
aligns one of the box’s <a data-link-type=dfn href=#last-baselines title="last baselines">last baselines</a>
with the corresponding <a data-link-type=dfn href=#last-baselines title="last baselines">last baselines</a>
of all the boxes in its <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">baseline-sharing group</a>.
<p>If the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>’s position is not fully determined by <a data-link-type=dfn href=#baseline-alignment title="baseline alignment">baseline alignment</a>,
the content is <a class=css data-link-type=maybe href=#valuedef-self-end title=self-end>self-end</a>-aligned insofar as possible while preserving the baseline alignment.
(Content that has no <a data-link-type=dfn href=#last-baselines title="last baselines">last baselines</a> is thus end-aligned.)
</dl><p></p>
<p>When specified for <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a>/<a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a>,
these values trigger <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>,
shifting the content of the box within the box,
and may also affect the sizing of the box itself.
See <a data-section="" href=#baseline-align-content>§4.1
Baseline Content-Alignment</a>.</p>
<p>When specified for <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a>/<a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a>,
these values trigger <a data-link-type=dfn href=#baseline-self-alignment title="baseline self-alignment">baseline self-alignment</a>,
shifting the entire box within its container,
which may affect the sizing of its container.
See <a data-section="" href=#baseline-align-self>§5.3
Baseline Self-Alignment</a>.</p>
<p class=issue id=issue-511afb431><a class=self-link href=#issue-511afb431></a>Add example images.
<p class=note>Note: The <a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visudet.html#propdef-vertical-align title=vertical-align>vertical-align</a> property will also need a <span class=css data-link-type=maybe title=first-baseline>first-baseline</span> value
because per CSS2.1 for inline blocks, <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> is equivalent to <a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a>.</p>
<hr>
<p>A <dfn data-dfn-type=dfn data-noexport="" id=baseline-sharing-group>baseline-sharing group<a class=self-link href=#baseline-sharing-group></a></dfn>
is composed of boxes that participate in baseline alignment together.
This is possible only if they</p>
<ul>
<li>share an <a data-link-type=dfn href=#shared-alignment-context title="alignment context">alignment context</a> whose axis is parallel to their <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>
<li>have the same <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#block-flow-direction title="block flow direction">block flow direction</a> and <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#line-orientation title="line orientation">line orientation</a>,
<li>participate in the same type of baseline alignment (first- vs. last-line, content- vs. self-alignment)
</ul>
<p>Boxes <dfn data-dfn-type=dfn data-noexport="" id=shared-alignment-context title="shared alignment context|alignment context">share an alignment context<a class=self-link href=#shared-alignment-context></a></dfn> along a particular axis when they are:</p>
<ul>
<li>table cells in the same row, along the table’s row (inline) axis
<li>table cells in the same column, along the table’s column (block) axis
<li>grid items in the same row, along the grid’s row (inline) axis
<li>grid items in the same column, along the grid’s colum (block) axis
<li>flex items in the same flex line, along the flex container’s main axis
</ul>
<p>Boxes in a <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">baseline-sharing group</a> are aligned to each other
using their <dfn data-dfn-type=dfn data-noexport="" id=alignment-baseline>alignment baseline<a class=self-link href=#alignment-baseline></a></dfn>.
This is the dominant baseline associated with
the box that generates their <a data-link-type=dfn href=#shared-alignment-context title="shared alignment context">shared alignment context</a>
on the first (last, for <a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a> alignment) <a data-link-type=dfn href=http://dev.w3.org/csswg/selectors-3/#first-formatted-line0 title="first formatted line">formatted line</a>.
For example, in horizontal writing modes,
specifying <a class=css data-link-type=propdesc href=#propdef-align-content title=align-content>align-content: baseline</a> on table cells in the same row
will align the alphabetic baselines of their <a data-link-type=dfn href=http://dev.w3.org/csswg/selectors-3/#first-formatted-line0 title="first formatted lines">first formatted lines</a>.</p>
<h3 class="heading settled heading" data-level=3.3 id=distribution-values><span class=secno>3.3 </span><span class=content>
Distributed Alignment: the <a class=css data-link-type=maybe href=#valuedef-space-between title=space-between>space-between</a>, <a class=css data-link-type=maybe href=#valuedef-space-around title=space-around>space-around</a>, and <a class=css data-link-type=maybe href=#valuedef-space-evenly title=space-evenly>space-evenly</a> keywords</span><a class=self-link href=#distribution-values></a></h3>
<p>The distribution values are used by <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> and <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a>
to distribute the items in the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>
evenly between the start and end edges of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>.
When the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> cannot be distributed in this way,
they behave as their <dfn data-dfn-type=dfn data-export="" id=fallback-alignment>fallback alignment<a class=self-link href=#fallback-alignment></a></dfn>.
Each distribution value has an associated <a class="production css-code" data-link-type=type href=#typedef-content-position title="<content-position>"><content-position></a> as a <a data-link-type=dfn href=#fallback-alignment title="fallback alignment">fallback alignment</a>,
but one can alternatively be explicitly specified in the property.</p>
<pre class=prod> <dfn class=css-code data-dfn-type=type data-export="" id=typedef-content-distribution><content-distribution><a class=self-link href=#typedef-content-distribution></a></dfn> = space-between | space-around | space-evenly | stretch</pre>
<dl data-dfn-for="<content-distribution>" data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for="<content-distribution>" data-dfn-type=value data-export="" id=valuedef-space-between>space-between<a class=self-link href=#valuedef-space-between></a></dfn>
<dd>
The items are evenly distributed in the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>.
The first item is placed flush with the start edge of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
the last item is placed flush with the end edge of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
and the remaining items are distributed so that the spacing between any two adjacent items is the same.
Unless otherwise specified,
this value falls back to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
<dt><dfn class=css-code data-dfn-for="<content-distribution>" data-dfn-type=value data-export="" id=valuedef-space-around>space-around<a class=self-link href=#valuedef-space-around></a></dfn>
<dd>
The items are evenly distributed in the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
with a half-size space on either end.
The items are distributed so that the spacing between any two adjacent items is the same,
and the spacing before the first and after the last item is half the size of the other spacing.
Unless otherwise specified,
this value falls back to <a class=css data-link-type=maybe href=#valuedef-center title=center>center</a>.
<dt><dfn class=css-code data-dfn-for="<content-distribution>" data-dfn-type=value data-export="" id=valuedef-space-evenly>space-evenly<a class=self-link href=#valuedef-space-evenly></a></dfn>
<dd>
The items are evenly distributed in the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
with a full-size space on either end.
The items are distributed so that the spacing between any two adjacent items,
before the first item,
and after the last item
is the same.
Unless otherwise specified,
this value falls back to <a class=css data-link-type=maybe href=#valuedef-center title=center>center</a>.
<dt><dfn class=css-code data-dfn-for="<content-distribution>" data-dfn-type=value data-export="" id=valuedef-stretch>stretch<a class=self-link href=#valuedef-stretch></a></dfn>
<dd>
If the combined size of the items is less than the size of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
any <span class=css data-link-for=width data-link-type=maybe title=auto>auto</span>-sized items have their size increased equally so that the combined size exactly fills the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>.
Otherwise,
or if there are no <span class=css data-link-for=width data-link-type=maybe title=auto>auto</span>-sized items,
this value is identical to <a class=css data-link-type=maybe href=#valuedef-flex-start title=flex-start>flex-start</a>.
<span class=note>(For layout modes other than flex layout, <a class=css data-link-type=maybe href=#valuedef-flex-start title=flex-start>flex-start</a> is identical to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.)</span>
</dl>
<p class=issue id=issue-511afb43><a class=self-link href=#issue-511afb43></a>
Add example images.
<h3 class="heading settled heading" data-level=3.4 id=overflow-values><span class=secno>3.4 </span><span class=content>
Overflow Alignment: the <a class=css data-link-type=maybe href=#valuedef-safe title=safe>safe</a> and <a class=css data-link-type=maybe href=#valuedef-true title=true>true</a> keywords</span><a class=self-link href=#overflow-values></a></h3>
<p>When the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is larger than the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
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.</p>
<p>To help combat this problem,
an <dfn data-dfn-type=dfn data-export="" id=overflow-alignment>overflow alignment<a class=self-link href=#overflow-alignment></a></dfn> 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.</p>
<p>If the <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> isn’t explicitly specified,
the default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is determined by the layout mode.
Document-centric layout modes, such as block layout, default to "safe" <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a>,
while design-centric layout modes, such as flex layout, default to "true" <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a>.</p>
<pre class=prod><dfn class=css-code data-dfn-type=type data-export="" id=typedef-overflow-position><overflow-position><a class=self-link href=#typedef-overflow-position></a></dfn> = true | safe</pre>
<dl data-dfn-for="<overflow-position>" data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for="<overflow-position>" data-dfn-type=value data-export="" id=valuedef-safe>safe<a class=self-link href=#valuedef-safe></a></dfn>
<dd>
If the size of the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> overflows the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is instead aligned as if the alignment mode were <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
<dt><dfn class=css-code data-dfn-for="<overflow-position>" data-dfn-type=value data-export="" id=valuedef-true>true<a class=self-link href=#valuedef-true></a></dfn>
<dd>
Regardless of the relative sizes of the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> and <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>,
the given alignment value is honored.
</dl>
<p class=issue id=issue-8fcc582f><a class=self-link href=#issue-8fcc582f></a>
Transplant example 10 from flexbox.
<h2 class="heading settled heading" data-level=4 id=content-distribution><span class=secno>4 </span><span class=content>
Content Distribution: the <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> and <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> properties</span><a class=self-link href=#content-distribution></a></h2>
<p>The <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> and <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> properties control alignment of the box’s content within the box.</p>
<div class=figure>
<img alt="Diagram showing that the alignment of the content within the element is affected." height=212 src=images/content-example.svg width=212>
</div>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-justify-content>justify-content<a class=self-link href=#propdef-justify-content></a></dfn>, <dfn class=css-code data-dfn-type=property data-export="" id=propdef-align-content>align-content<a class=self-link href=#propdef-align-content></a></dfn><tr><th>Value:<td class=prod>auto | <a class="production css-code" data-link-type=type href=#typedef-baseline-position title="<baseline-position>"><baseline-position></a> | [ <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> <a class="production css-code" data-link-type=type href=#typedef-content-position title="<content-position>"><content-position></a>? | <a class="production css-code" data-link-type=type href=#typedef-content-position title="<content-position>"><content-position></a> ] && <a class="production css-code" data-link-type=type href=#typedef-overflow-position title="<overflow-position>"><overflow-position></a>?<tr><th>Initial:<td>auto<tr><th>Applies to:<td>block containers, flex containers, and grid containers<tr><th>Inherited:<td>no<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a<tr><th>Animatable:<td>no</table>
<p>Aligns the contents of the box as a whole along the box’s inline/row/main axis.
Values other than <dfn class=css-code data-dfn-for="justify-content, align-content" data-dfn-type=value data-export="" id=valuedef-auto0>auto<a class=self-link href=#valuedef-auto0></a></dfn> are <a href=#alignment-values>defined above</a>.
If both a <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> and <a class="production css-code" data-link-type=type href=#typedef-content-position title="<content-position>"><content-position></a> are given,
the second value represents an explicit <a data-link-type=dfn href=#fallback-alignment title="fallback alignment">fallback alignment</a>.</p>
<hr>
<dl>
<dt>Block Containers:
<dd>
The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn title="block container">block container</a>’s content box.
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the entire contents of the block.
<p>The <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> property applies along the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#block-axis- title="block axis">block axis</a>,
but if a <var><content-distribution></var> is specified
the <a data-link-type=dfn href=#fallback-alignment title="fallback alignment">fallback alignment</a> is used instead.
The <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> property does not apply to and has no effect on block containers.</p>
<p>All values other than <span class=css data-link-for=justify-content data-link-type=maybe title=auto>auto</span> force the block container to establish a new formatting context.
For table cells, the behavior of the <span class=css data-link-for=justify-content data-link-type=maybe title=auto>auto</span> depends on the computed value of <a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visudet.html#propdef-vertical-align title=vertical-align>vertical-align</a>:
<a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-writing-modes-3/#top title=top>top</a> makes it behave as <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>,
<span class=css data-link-type=maybe title=middle>middle</span> makes it behave as <a class=css data-link-type=maybe href=#valuedef-center title=center>center</a>,
<a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-writing-modes-3/#bottom title=bottom>bottom</a> makes it behave as <a class=css data-link-type=maybe href=#valuedef-end title=end>end</a>,
and all other values make it behave as <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a>.
<span class=css data-link-for=justify-content data-link-type=maybe title=auto>auto</span> otherwise behaves as <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.</p>
<dt>Multicol Layout:
<dd>
The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-multicol-1/#multi-column-element title="multi-column element">multi-column element</a>’s content box.
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the column boxes, as a unit.
<p>The <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> property applies along the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#block-axis- title="block axis">block axis</a>,
but if a <var><content-distribution></var> is specified
the <a data-link-type=dfn href=#fallback-alignment title="fallback alignment">fallback alignment</a> is used instead.
The <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> property does not apply to and has no effect on multi-column elements.</p>
<p><span class=css data-link-for=justify-content data-link-type=maybe title=auto>auto</span> behaves as <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.</p>
<dt>Flex Containers:
<dd>
<span class=css data-link-for=justify-content data-link-type=maybe title=auto>auto</span> computes to <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a>.
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-container title="flex container">flex container</a>’s content box.
For <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a>, the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-item title="flex items">flex items</a> in each <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-line title="flex line">flex line</a>;
for <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a>, the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-line title="flex lines">flex lines</a>.</p>
<p>The <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> property applies along the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#cross-axis title="cross axis">cross axis</a>.
The <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> property applies along the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#main-axis title="main axis">main axis</a>,
but <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> behaves as <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.</p>
<p>See <a data-biblio-type=normative data-link-type=biblio href=#css3-flexbox title=css3-flexbox>[CSS3-FLEXBOX]</a> for details.</p>
<dt>Grid Containers:
<dd>
<span class=css data-link-for=justify-content data-link-type=maybe title=auto>auto</span> computes to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>, and <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> behaves like <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a>.
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-container title="grid container">grid container</a>’s content box.
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the bounds of the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid title=grid>grid</a>.
<span class=issue id=issue-dda0e769><a class=self-link href=#issue-dda0e769></a>Need to dfn a better term for this in Grid.</span></p>
<p>The <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> property applies along the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#block-axis- title="block axis">block (column) axis</a>.
The <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> property applies along the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline (row) axis</a>.
In both properties, if a <var><content-distribution></var> is specified,
the <a data-link-type=dfn href=#fallback-alignment title="fallback alignment">fallback alignment</a> is used instead.
</dl><p></p>
<h3 class="heading settled heading" data-level=4.1 id=baseline-align-content><span class=secno>4.1 </span><span class=content>
Baseline Content-Alignment</span><a class=self-link href=#baseline-align-content></a></h3>
<p>The content of boxes participating in row-like layout contexts (<a data-link-type=dfn href=#shared-alignment-context title="shared alignment contexts">shared alignment contexts</a>)
can be baseline-aligned to each other.
This effectively increases the padding on the box
to align the <a data-link-type=dfn href=#alignment-baseline title="alignment baseline">alignment baseline</a> of its contents
with that of other baseline-aligned boxes in its <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">group</a>.</p>
<p>The set of boxes that participate in <dfn data-dfn-type=dfn data-export="" id=baseline-content-alignment title="baseline content-alignment|first-baseline content-alignment|last-baseline content-alignment">baseline content-alignment<a class=self-link href=#baseline-content-alignment></a></dfn>
depends on the layout model:</p>
<dl>
<dt>Table Cells:
<dd>
A <a data-link-type=dfn title="table cell">table cell</a> participates in first (last) <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>
in either its row or column (whichever matches its <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>)
if its computed <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> is <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> (<a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a>).
<dt>Flex Items:
<dd>
A <a data-link-type=dfn href=http://dev.w3.o
10BC8
rg/csswg/css-flexbox-1/#flex-item title="flex item">flex item</a> participates in first (last) <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>
in its flex line if
its computed <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> is <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> (<a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a>)
and its computed <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> is <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> or <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> (<a class=css data-link-type=maybe href=#valuedef-end title=end>end</a>).
<dt>Grid Items:
<dd>
A <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-item title="grid item">grid item</a> participates in first (last) <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>
in either its row or column (whichever matches its <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>)
if its computed <a class=property data-link-type=propdesc href=#propdef-align-content title=align-content>align-content</a> is <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> (<a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a>),
and its computed <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> or <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> (whichever affects its <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#block-axis- title="block axis">block axis</a>) is <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> or <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> (<a class=css data-link-type=maybe href=#valuedef-end title=end>end</a>).
</dl>
<p>If a box spans multiple <a data-link-type=dfn href=#shared-alignment-context title="shared alignment contexts">shared alignment contexts</a>,
it participates in first (last) <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>
within its start-most (end-most) <a data-link-type=dfn href=#shared-alignment-context title="shared alignment context">shared alignment context</a> along that axis.</p>
<p>When a box participates in first (last) <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>
its <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is aligned to the start (end) edge of its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
and the minimum necessary extra space is added between its start (end) edge and the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>
to match its <a data-link-type=dfn href=#alignment-baseline title="alignment baseline">alignment baseline</a> in that axis up to that of its <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">baseline-sharing group</a>.
This increases the intrinsic size of the box.</p>
<h2 class="heading settled heading" data-level=5 id=self-alignment><span class=secno>5 </span><span class=content>
Self-Alignment: Aligning the Box within its Parent</span><a class=self-link href=#self-alignment></a></h2>
<p>The <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> and <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> properties control alignment of the box within its containing block.</p>
<div class=figure>
<img alt="Diagram showing that the alignment of the element within its containing block is affected." height=212 src=images/self-example.svg width=212>
</div>
<h3 class="heading settled heading" data-level=5.1 id=justify-self-property><span class=secno>5.1 </span><span class=content>
Inline/Main-Axis Alignment: the <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> property</span><a class=self-link href=#justify-self-property></a></h3>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-justify-self>justify-self<a class=self-link href=#propdef-justify-self></a></dfn><tr><th>Value:<td class=prod>auto | <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> | <a class="production css-code" data-link-type=type href=#typedef-baseline-position title="<baseline-position>"><baseline-position></a> | [ <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> && <a class="production css-code" data-link-type=type href=#typedef-overflow-position title="<overflow-position>"><overflow-position></a>? ]<tr><th>Initial:<td>auto<tr><th>Applies to:<td>block-level boxes, absolutely-positioned boxes, and grid items<tr><th>Inherited:<td>no<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a<tr><th>Animatable:<td>no</table>
<p>Justifies the box within its parent along the inline/row/main axis:
the box’s outer edges are aligned within its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
<a href=#alignment-values>as described by its alignment value</a>.</p>
<p>The <dfn class=css-code data-dfn-for=justify-self data-dfn-type=value data-export="" id=valuedef-auto1>auto<a class=self-link href=#valuedef-auto1></a></dfn> keyword computes to
<a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> on absolutely-positioned elements,
and to the computed value of <a class=property data-link-type=propdesc href=#propdef-justify-items title=justify-items>justify-items</a> on the parent
(minus any <a class=css data-link-type=maybe href=#valuedef-legacy title=legacy>legacy</a> keywords) on all other boxes.</p>
<hr>
<dl>
<dt>Block-level Boxes:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> property applies along its containing block’s <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>.
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> 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 <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is reduced by the space taken up by the float.
(Note: This is the legacy behavior of HTML <code>align</code>.)
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the block’s margin box.</p>
<p>The default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is <a class=css data-link-type=maybe href=#valuedef-safe title=safe>safe</a>.
In terms of CSS2.1 block-level formatting <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a>,
the rules for "over-constrained" computations in <a href=http://www.w3.org/TR/CSS21/visudet.html#blockwidth>section 10.3.3</a>
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.</p>
<p>The <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> value is equivalent to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> on block-level boxes.</p>
<p>This property does not apply to floats.</p>
<dt>Absolutely-positioned Boxes:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> property applies along its containing block’s <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>.
<p>When neither margin in this dimension is <span class=css data-link-for=margin data-link-type=maybe title=auto>auto</span>
and neither offset property in this dimension is <span class=css data-link-for=top data-link-type=maybe title=auto>auto</span>,
values other than <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> cause <a href=http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width>non-replaced absolutely-positioned boxes</a>
to use shrink-to-fit sizing for calculating <span class=css data-link-for=width data-link-type=maybe title=auto>auto</span> measures,
and <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> dictates alignment as follows:</p>
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the box’s containing block
as modified by the offset properties (<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#top title=top>top</a>/<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#right title=right>right</a>/<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#bottom title=bottom>bottom</a>/<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#left title=left>left</a>).
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the box’s margin box.</p>
<p>The default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is <a class=css data-link-type=maybe href=#valuedef-safe title=safe>safe</a>.
In terms of CSS2.1 formatting <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a>,
the rules for "over-constrained" computations in <a href=http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width>section 10.3.7</a>
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.</p>
<p>The <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> keyword is equivalent to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> on replaced absolutely-positioned boxes.
(This is because CSS 2.1 does not stretch replaced elements to fit into fixed offsets.)</p>
<dt>Table Cells:
<dd>
This property does not apply to table cells,
because their position and size is fully constrained by table layout.
<dt>Flex Items:
<dd>
This property does not apply to <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-item title="flex items">flex items</a>,
because there is more than one item in the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#main-axis title="main axis">main axis</a>.
See <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-flexbox-1/#propdef-flex title=flex>flex</a> for stretching and <a class=property data-link-type=propdesc href=#propdef-justify-content title=justify-content>justify-content</a> for <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#main-axis title=main-axis>main-axis</a> alignment. <a data-biblio-type=normative data-link-type=biblio href=#css3-flexbox title=css3-flexbox>[CSS3-FLEXBOX]</a>
<dt>Grid Items:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> property applies along the grid’s <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#row-axis title="row axis">row axis</a>.
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-cell title="grid cell">grid cell</a>.
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-item title="grid item">grid item</a>’s margin box.
The default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is <a class=css data-link-type=maybe href=#valuedef-true title=true>true</a>.
</dl><p></p>
<p class=issue id=issue-225803b9><a class=self-link href=#issue-225803b9></a>
Should we make <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> actually work on block-level/abspos replaced boxes?
To maintain legacy compat, this requires adding a new value (named <span class=css data-link-type=maybe title=normal>normal</span>?)
which has the current behavior of stretching non-replaced boxes and start-aligning replaced ones.
<div class=example>
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.
</div>
<h3 class="heading settled heading" data-level=5.2 id=align-self-property><span class=secno>5.2 </span><span class=content>
Block/Cross-Axis Alignment: the <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> property</span><a class=self-link href=#align-self-property></a></h3>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-align-self>align-self<a class=self-link href=#propdef-align-self></a></dfn><tr><th>Value:<td class=prod>auto | <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> | <a class="production css-code" data-link-type=type href=#typedef-baseline-position title="<baseline-position>"><baseline-position></a> | [ <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> && <a class="production css-code" data-link-type=type href=#typedef-overflow-position title="<overflow-position>"><overflow-position></a>? ]<tr><th>Initial:<td>auto<tr><th>Applies to:<td>block-level boxes<tr><th>Inherited:<td>no<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a<tr><th>Animatable:<td>no</table>
<p>Aligns the box within its parent along the block/column/cross axis:
the box’s outer edges are aligned within its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
<a href=#alignment-values>as described by its alignment value</a>.</p>
<p>The <dfn class=css-code data-dfn-for=align-self data-dfn-type=value data-export="" id=valuedef-auto2>auto<a class=self-link href=#valuedef-auto2></a></dfn> keyword computes to
<a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> on absolutely-positioned elements,
and to the computed value of <a class=property data-link-type=propdesc href=#propdef-align-items title=align-items>align-items</a> on the parent
(minus any <a class=css data-link-type=maybe href=#valuedef-legacy title=legacy>legacy</a> keywords) on all other boxes.</p>
<hr>
<dl>
<dt>Block-level Boxes:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> property does not apply to block-level boxes
(including floats),
because there is more than one item in the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#block-axis- title="block axis">block axis</a>.
<dt>Absolutely-positioned Boxes:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> property applies along its containing block’s <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>.
<p>When neither margin in this dimension is <span class=css data-link-for=margin data-link-type=maybe title=auto>auto</span>
and neither offset property in this dimension is <span class=css data-link-for=top data-link-type=maybe title=auto>auto</span>,
values other than <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> cause <a href=http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-height>non-replaced absolutely-positioned boxes</a>
to use shrink-to-fit sizing for calculating <span class=css data-link-for=width data-link-type=maybe title=auto>auto</span> measures,
and <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> dictates alignment as follows:</p>
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the box’s containing block
as modified by the offset properties (<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#top title=top>top</a>/<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#right title=right>right</a>/<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#bottom title=bottom>bottom</a>/<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#left title=left>left</a>).
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the box’s margin box.</p>
<p>The default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is <a class=css data-link-type=maybe href=#valuedef-safe title=safe>safe</a>.
In terms of CSS2.1 formatting <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a>,
the rules for "over-constrained" computations in <a href=http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-height>section 10.6.4</a>
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.</p>
<p>The <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> keyword is equivalent to <a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> on replaced absolutely-positioned boxes.
(This is because CSS 2.1 does not stretch replaced elements to fit into fixed offsets.)</p>
<dt>Table Cells:
<dd>
This property does not apply to table cells,
because their position and size is fully constrained by table layout.
<dt>Flex Items:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> property applies along the flexbox’s <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#cross-axis title="cross axis">cross axis</a>.
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-line title="flex line">flex line</a> the item is in.
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-item title="flex item">flex item</a>’s margin box.
The default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is <a class=css data-link-type=maybe href=#valuedef-true title=true>true</a>.
See <a data-biblio-type=normative data-link-type=biblio href=#css3-flexbox title=css3-flexbox>[CSS3-FLEXBOX]</a> for details.</p>
<dt>Grid Items:
<dd>
The <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> property applies along the grid’s <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#column-axis title="column axis">column axis</a>.
<p>The <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-cell title="grid cell">grid cell</a>.
The <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-item title="grid item">grid item</a>’s margin box.
The default <a data-link-type=dfn href=#overflow-alignment title="overflow alignment">overflow alignment</a> is <a class=css data-link-type=maybe href=#valuedef-true title=true>true</a>.
</dl><p></p>
<h3 class="heading settled heading" data-level=5.3 id=baseline-align-self><span class=secno>5.3 </span><span class=content>
Baseline Self-Alignment</span><a class=self-link href=#baseline-align-self></a></h3>
<p>Boxes participating in row-like layout contexts (<a data-link-type=dfn href=#shared-alignment-context title="shared alignment contexts">shared alignment contexts</a>)
can be baseline-aligned to each other.
This effectively increases the margins on the box
to align its <a data-link-type=dfn href=#alignment-baseline title="alignment baseline">alignment baseline</a>
with other baseline-aligned boxes in its <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">group</a>.</p>
<p>The set of boxes that participate in <dfn data-dfn-type=dfn data-export="" id=baseline-self-alignment title="baseline self-alignment|first-baseline self-alignment|last-baseline self-alignment">baseline self-alignment<a class=self-link href=#baseline-self-alignment></a></dfn>
depends on the layout model:</p>
<dl>
<dt>Flex Items:
<dd>
A <a data-link-type=dfn href=http://dev.w3.org/csswg/css-flexbox-1/#flex-item title="flex item">flex item</a> participates in first (last) <a data-link-type=dfn href=#baseline-self-alignment title="baseline self-alignment">baseline self-alignment</a> in its flex line
if its computed <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> is <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> (<a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a>).
See <a data-biblio-type=normative data-link-type=biblio href=#css3-flexbox title=css3-flexbox>[CSS3-FLEXBOX]</a> for details.
<dt>Grid Items:
<dd>
A <a data-link-type=dfn href=http://dev.w3.org/csswg/css-grid-1/#grid-item title="grid item">grid item</a> participates in first (last) <a data-link-type=dfn href=#baseline-content-alignment title="baseline content-alignment">baseline content-alignment</a>
in either its row or column (whichever matches its <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>)
if its <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> or <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> property (whichever matches its <a data-link-type=dfn href=http://dev.w3.org/csswg/css-writing-modes-3/#inline-axis- title="inline axis">inline axis</a>)
computes to <a class=css data-link-type=maybe href=#valuedef-baseline title=baseline>baseline</a> (<a class=css data-link-type=maybe href=#valuedef-last-baseline title=last-baseline>last-baseline</a>).
</dl>
<p>If a box spans multiple <a data-link-type=dfn href=#shared-alignment-context title="shared alignment contexts">shared alignment contexts</a>,
it participates in first (last) <a data-link-type=dfn href=#baseline-self-alignment title="baseline self-alignment">baseline self-alignment</a>
within its start-most (end-most) <a data-link-type=dfn href=#shared-alignment-context title="shared alignment context">shared alignment context</a> along that axis.</p>
<p>When a box participates in first (last) <a data-link-type=dfn href=#baseline-self-alignment title="baseline self-alignment">baseline self-alignment</a>
its <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a> is aligned to the start (end) edge of its <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
and the minimum necessary extra space is added between its start (end) edge and the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>
to match its <a data-link-type=dfn href=#alignment-baseline title="alignment baseline">alignment baseline</a> in that axis up to that of its <a data-link-type=dfn href=#baseline-sharing-group title="baseline-sharing group">baseline-sharing group</a>.
This may increase the intrinsic size contribution of the <a data-link-type=dfn href=#alignment-subject title="alignment subject">alignment subject</a>.</p>
<h2 class="heading settled heading" data-level=6 id=default-alignment><span class=secno>6 </span><span class=content>
Default Alignment</span><a class=self-link href=#default-alignment></a></h2>
<p>The <a class=property data-link-type=propdesc href=#propdef-align-items title=align-items>align-items</a> and <a class=property data-link-type=propdesc href=#propdef-justify-items title=justify-items>justify-items</a> properties set the default <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> and <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> behavior of the items contained by the element.</p>
<div class=figure>
<img alt="Diagram showing that the alignment of grid items within the element is affected." height=212 src=images/items-example.svg width=212>
</div>
<h3 class="heading settled heading" data-level=6.1 id=justify-items-property><span class=secno>6.1 </span><span class=content>
Inline/Main-Axis Alignment: the <a class=property data-link-type=propdesc href=#propdef-justify-items title=justify-items>justify-items</a> property</span><a class=self-link href=#justify-items-property></a></h3>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-justify-items>justify-items<a class=self-link href=#propdef-justify-items></a></dfn><tr><th>Value:<td class=prod>auto | <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> | <a class="production css-code" data-link-type=type href=#typedef-baseline-position title="<baseline-position>"><baseline-position></a> | [ <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> && <a class="production css-code" data-link-type=type href=#typedef-overflow-position title="<overflow-position>"><overflow-position></a>? ] | [ legacy && [ <a class=css data-link-type=maybe href=#valuedef-left title=left>left</a> | <a class=css data-link-type=maybe href=#valuedef-right title=right>right</a> | <a class=css data-link-type=maybe href=#valuedef-center title=center>center</a> ] ]<tr><th>Initial:<td>auto<tr><th>Applies to:<td>block containers, flex containers, and grid containers<tr><th>Inherited:<td>no<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a<tr><th>Animatable:<td>no</table>
<p>This property specifies the default <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a> for all of the boxes
(including anonymous boxes)
participating in this box’s formatting context.
Values have the following meanings:</p>
<dl data-dfn-for=justify-items data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=justify-items data-dfn-type=value data-export="" id=valuedef-auto3>auto<a class=self-link href=#valuedef-auto3></a></dfn>
<dd>
If the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-cascade-3/#inherited-value title="inherited value">inherited value</a> of <span class=css data-link-type=maybe title=justify-items>justify-items</span> includes the <a class=css data-link-type=maybe href=#valuedef-legacy title=legacy>legacy</a> keyword,
<a class=css data-link-for=justify-items data-link-type=maybe href=#valuedef-auto3 title=auto>auto</a> computes to the the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-cascade-3/#inherited-value title="inherited value">inherited value</a>.
<p>Otherwise, <a class=css data-link-for=justify-items data-link-type=maybe href=#valuedef-auto3 title=auto>auto</a> computes to:</p>
<ul>
<li><a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> for flex containers and grid containers
<li><a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> for everything else
</ul>
<dt><dfn class=css-code data-dfn-for=justify-items data-dfn-type=value data-export="" id=valuedef-legacy>legacy<a class=self-link href=#valuedef-legacy></a></dfn>
<dd>
This keyword causes the value to effectively inherit into descendants.
It can only be combined with the <a class=css data-link-type=maybe href=#valuedef-center title=center>center</a>, <a class=css data-link-type=maybe href=#valuedef-left title=left>left</a>, and <a class=css data-link-type=maybe href=#valuedef-right title=right>right</a> positions.
The alignment keyword, but not the <a class=css data-link-type=maybe href=#valuedef-legacy title=legacy>legacy</a> keyword, is passed to <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a>.
It exists to implement the legacy alignment behavior of HTML’s <code><center></code> element and <code>align</code> attribute.
</dl>
<p>Other values have no special handling and are merely passed to <a class=property data-link-type=propdesc href=#propdef-justify-self title=justify-self>justify-self</a>.</p>
<h3 class="heading settled heading" data-level=6.2 id=align-items-property><span class=secno>6.2 </span><span class=content>
Block/Cross-Axis Alignment: the <a class=property data-link-type=propdesc href=#propdef-align-items title=align-items>align-items</a> property</span><a class=self-link href=#align-items-property></a></h3>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-align-items>align-items<a class=self-link href=#propdef-align-items></a></dfn><tr><th>Value:<td class=prod>auto | <a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> | <a class="production css-code" data-link-type=type href=#typedef-baseline-position title="<baseline-position>"><baseline-position></a> | [ <a class="production css-code" data-link-type=type href=#typedef-item-position title="<item-position>"><item-position></a> && <a class="production css-code" data-link-type=type href=#typedef-overflow-position title="<overflow-position>"><overflow-position></a>? ]<tr><th>Initial:<td>auto<tr><th>Applies to:<td>block-level elements<tr><th>Inherited:<td>no<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a<tr><th>Animatable:<td>no</table>
<p>This property specifies the default <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a> for all of the boxes
(including anonymous boxes)
participating in this box’s formatting context.
Values have the following meanings:</p>
<dl data-dfn-for=align-items data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=align-items data-dfn-type=value data-export="" id=valuedef-auto>auto<a class=self-link href=#valuedef-auto></a></dfn>
<dd>
Computes to:
<ul>
<li><a class=css data-link-type=maybe href=#valuedef-stretch title=stretch>stretch</a> for flex containers and grid containers
<li><a class=css data-link-type=maybe href=#valuedef-start title=start>start</a> for everything else
</ul>
</dl>
<p>Other values have no special handling and are merely passed to <a class=property data-link-type=propdesc href=#propdef-align-self title=align-self>align-self</a>.</p>
<h2 class="heading settled heading" data-level=7 id=baseline-rules><span class=secno>7 </span><span class=content>
Determining the Baseline of a Box</span><a class=self-link href=#baseline-rules></a></h2>
<p>The <dfn data-dfn-type=dfn data-noexport="" id=baselines-of-a-box title="baselines of a box"><a class=self-link href=#baselines-of-a-box></a></dfn><dfn data-dfn-type=dfn data-noexport="" id=first-baselines>first baselines<a class=self-link href=#first-baselines></a></dfn> (and <dfn data-dfn-type=dfn data-noexport="" id=last-baselines>last baselines<a class=self-link href=#last-baselines></a></dfn>) of a box
for a given axis
are a set of baselines (alphabetic, central, etc.)
nominally associated with the first (last) line of text within the box.
The <a data-link-type=dfn href=#alignment-baseline title="alignment baseline">alignment baseline</a> is one of these,
usually the dominant baseline of the <a data-link-type=dfn href=#alignment-container title="alignment container">alignment container</a>.
(See <a class=property data-link-type=propdesc href=http://www.w3.org/TR/SVG/text.html#AlignmentBaselineProperty title=alignment-baseline>alignment-baseline</a>.)
Note that boxes might not have baselines in a particular axis.</p>
<p>The first and last <a data-link-type=dfn href=#baselines-of-a-box title="baselines of a box">baselines of a box</a>
are determined differently based on the layout model, as follows:</p>
<dl>
<dt>block containers
<dd>
The first (last) inline-axis baselines of a block container
are generated from the dominant baseline of the first (last) in-flow line box in the block container,
or are taken from the first (last) in-flow block-level child in the block container that contributes a set of baselines,
whichever comes first (last).
If there is no such line box or child,
then the block container has no baselines.
For the purposes of finding the baselines,
in-flow boxes with a scrolling mechanisms (see the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-overflow-3/#overflow0 title=overflow>overflow</a> property)
must be considered as if scrolled to their origin (final) position.
<p>A block container has no block-axis baselines.</p>