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<!DOCTYPE html><html lang=en><head>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
<title>Media Queries Level 4</title>
<link href=../default.css rel=stylesheet type=text/css>
<link href=../csslogo.ico rel="shortcut icon" type=image/x-icon>
<link href=https://www.w3.org/StyleSheets/TR/W3C-WD rel=stylesheet type=text/css>
<style>svg.railroad-diagram{background-color:hsl(30,20%,95%);}svg.railroad-diagram path{stroke-width:3;stroke:black;fill:rgba(0,0,0,0);}svg.railroad-diagram text{font:bold 14px monospace;text-anchor:middle;}svg.railroad-diagram text.label{text-anchor:start;}svg.railroad-diagram text.comment{font:italic 12px monospace;}svg.railroad-diagram rect{stroke-width:3;stroke:black;fill:hsl(120,100%,90%);}</style><style>svg.railroad-diagram{background-color:hsl(30,20%,95%);}svg.railroad-diagram path{stroke-width:3;stroke:black;fill:rgba(0,0,0,0);}svg.railroad-diagram text{font:bold 14px monospace;text-anchor:middle;}svg.railroad-diagram text.label{text-anchor:start;}svg.railroad-diagram text.comment{font:italic 12px monospace;}svg.railroad-diagram rect{stroke-width:3;stroke:black;fill:hsl(120,100%,90%);}</style><style>svg.railroad-diagram{background-color:hsl(30,20%,95%);}svg.railroad-diagram path{stroke-width:3;stroke:black;fill:rgba(0,0,0,0);}svg.railroad-diagram text{font:bold 14px monospace;text-anchor:middle;}svg.railroad-diagram text.label{text-anchor:start;}svg.railroad-diagram text.comment{font:italic 12px monospace;}svg.railroad-diagram rect{stroke-width:3;stroke:black;fill:hsl(120,100%,90%);}</style><style>svg.railroad-diagram{background-color:hsl(30,20%,95%);}svg.railroad-diagram path{stroke-width:3;stroke:black;fill:rgba(0,0,0,0);}svg.railroad-diagram text{font:bold 14px monospace;text-anchor:middle;}svg.railroad-diagram text.label{text-anchor:start;}svg.railroad-diagram text.comment{font:italic 12px monospace;}svg.railroad-diagram rect{stroke-width:3;stroke:black;fill:hsl(120,100%,90%);}</style><style>
#pointer-hover-table { margin: 1em auto; text-align: center; border-collapse: collapse; max-width: 40em; }
#pointer-hover-table td, #pointer-hover-table th { padding: .5em; }
#pointer-hover-table thead tr+tr th { border-bottom: 1px solid silver; }
#pointer-hover-table tbody td:first-of-type { border-left: 1px solid silver; }
</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=https://www.w3.org/Icons/w3c_home width=72>
</a>
</p>
<h1 class="p-name no-ref" id=title>Media Queries Level 4</h1>
<h2 class="no-num no-toc no-ref heading settled heading" id=subtitle><span class=content>W3C First Public Working Draft,
<span class=dt-updated><span class=value-title title=20140603>3 June 2014</span></span></span></h2>
<div data-fill-with=spec-metadata><dl>
<dt>This version:
<dd><a class=u-url href=http://www.w3.org/TR/2014/WD-mediaqueries-4-20140603/>http://www.w3.org/TR/2014/WD-mediaqueries-4-20140603/</a>
<dt>Latest version:
<dd><a href=http://www.w3.org/TR/mediaqueries4/>http://www.w3.org/TR/mediaqueries4/</a>
<dt>Editor’s Draft:
<dd><a href=http://dev.w3.org/csswg/mediaqueries4/>http://dev.w3.org/csswg/mediaqueries4/</a>
<dt>Feedback:
<dd><a href="mailto:www-style@w3.org?subject=%5Bmediaqueries%5D%20feedback">www-style@w3.org</a>
with subject line
“<kbd>[mediaqueries] <var>… message topic …</var></kbd>”(<a href=http://lists.w3.org/Archives/Public/www-style/ rel=discussion>archives</a>)
<dt>Editors:
<dd><dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:florian@rivoal.net>Florian Rivoal</a> (<span class="p-org org">Invited Expert</span>)
<dd><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>Former Editors:
<dd><dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:howcome@opera.com>Håkon Wium Lie</a> (<span class="p-org org">Opera</span>)
<dd><dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:tantek@cs.standard.edu>Tantek Çelik</a> (<span class="p-org org">Mozilla</span>)
<dd><dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:daniel@glazman.org>Daniel Glazman</a> (<span class="p-org org">Disruptive Innovations</span>)
<dd><dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:annevk@annevk.nl>Anne van Kesteren</a> (<span class="p-org org">Mozilla</span>)
<dt>Issue Tracking:
<dd><a href=#issues-index>Inline</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>
<div class=p-summary data-fill-with=abstract><p><a data-link-type=dfn href=#media-query title="media queries">Media Queries</a> allow authors to test and query values or features of the user agent or display device, independent of the document being rendered. They are used in the CSS @media rule to conditionally apply styles to a document, and in various other contexts and languages, such as HTML and Javascript.</p>
<p>Media Queries Level 4 describes the mechanism and syntax of media queries, media types, and media features. It extends and supersedes the features defined in Media Queries Level 3.</p>
<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.</div>
<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><em>This section describes the status of this document at the time of
its publication. Other documents may supersede this document. A list of
current W3C publications and the latest revision of this technical report
can be found in the <a href=http://www.w3.org/TR/>W3C technical reports
index at http://www.w3.org/TR/.</a></em>
<p>This document is a <b>First Public Working Draft</b>.
<p>Publication as a First Public Working Draft does not imply endorsement by the W3C
Membership. This is a draft document and may be updated, replaced or
obsoleted by other documents at any time. It is inappropriate to cite this
document as other than work in progress.
<p>The (<a href=http://lists.w3.org/Archives/Public/www-style/>archived</a>) public
mailing list <a href=mailto:www-style@w3.org>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 “mediaqueries” in the subject, preferably like this:
“[mediaqueries] <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>.</p>
</div>
<div data-fill-with=at-risk></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>
<li><a href=#units><span class=secno>1.3</span> Units</a></ul>
<li><a href=#media><span class=secno>2</span> Media Queries</a>
<ul class=toc>
<li><a href=#mq-list><span class=secno>2.1</span> Combining Media Queries</a>
<li><a href=#mq-prefix><span class=secno>2.2</span> Media Query Modifiers</a>
<ul class=toc>
<li><a href=#mq-not><span class=secno>2.2.1</span> Negating a Media Query: the <span class=css data-link-type=maybe title=not>not</span> keyword</a>
<li><a href=#mq-only><span class=secno>2.2.2</span> Hiding a Media Query From Legacy User Agents: the <span class=css data-link-type=maybe title=only>only</span> keyword</a></ul>
<li><a href=#media-types><span class=secno>2.3</span> Media Types</a>
<li><a href=#mq-features><span class=secno>2.4</span> Media Features</a>
<ul class=toc>
<li><a href=#mq-ranges><span class=secno>2.4.1</span> Media Feature Types: “range” and “discrete”</a>
<li><a href=#mq-boolean-context><span class=secno>2.4.2</span> Evaluating Media Features in a Boolean Context</a>
<li><a href=#mq-range-context><span class=secno>2.4.3</span> Evaluating Media Features in a Range Context</a>
<li><a href=#mq-min-max><span class=secno>2.4.4</span> Using “min-” and “max-” Prefixes On Range Features</a></ul></ul>
<li><a href=#mq-syntax><span class=secno>3</span> Syntax</a>
<ul class=toc>
<li><a href=#error-handling><span class=secno>3.1</span> Error Handling</a></ul>
<li><a href=#mf-dimensions><span class=secno>4</span> Screen/Device Dimensions Media Features</a>
<ul class=toc>
<li><a href=#width><span class=secno>4.1</span> width</a>
<li><a href=#height><span class=secno>4.2</span> height</a>
<li><a href=#aspect-ratio><span class=secno>4.3</span> aspect-ratio</a>
<li><a href=#orientation><span class=secno>4.4</span> orientation</a>
<li><a href=#device-width><span class=secno>4.5</span> device-width</a>
<li><a href=#device-height><span class=secno>4.6</span> device-height</a>
<li><a href=#device-aspect-ratio><span class=secno>4.7</span> device-aspect-ratio</a></ul>
<li><a href=#mf-display-quality><span class=secno>5</span> Display Quality Media Features</a>
<ul class=toc>
<li><a href=#resolution><span class=secno>5.1</span> resolution</a>
<li><a href=#scan><span class=secno>5.2</span> scan</a>
<li><a href=#grid><span class=secno>5.3</span> grid</a>
<li><a href=#update-frequency><span class=secno>5.4</span> update-frequency</a>
<li><a href=#mf-overflow-block><span class=secno>5.5</span> overflow-block</a>
<li><a href=#mf-overflow-inline><span class=secno>5.6</span> overflow-inline</a></ul>
<li><a href=#mf-colors><span class=secno>6</span> Color Media Features</a>
<ul class=toc>
<li><a href=#color><span class=secno>6.1</span> color</a>
<li><a href=#color-index><span class=secno>6.2</span> color-index</a>
<li><a href=#monochrome><span class=secno>6.3</span> monochrome</a></ul>
<li><a href=#mf-interaction><span class=secno>7</span> Interaction Media Features</a>
<ul class=toc>
<li><a href=#pointer><span class=secno>7.1</span> pointer</a>
<li><a href=#hover><span class=secno>7.2</span> hover</a>
<li><a href=#any-input><span class=secno>7.3</span> any-pointer and any-hover</a></ul>
<li><a href=#mf-environment><span class=secno>8</span> Environment Media Features</a>
<ul class=toc>
<li><a href=#light-level><span class=secno>8.1</span> light-level</a></ul>
<li><a href=#mf-scripting><span class=secno>9</span> Scripting Media Features</a>
<ul class=toc>
<li><a href=#scripting><span class=secno>9.1</span> scripting</a></ul>
<li><a href=#assorted-issues><span class=secno>10</span> Assorted Issues</a>
<li><a href=#custom-mq><span class=secno>11</span> Custom Media Queries</a>
<ul class=toc>
<li><a href=#script-custom-mq><span class=secno>11.1</span> Script-based Custom Media Queries</a>
<li><a href=#custom-mq-cssom><span class=secno>11.2</span> CSSOM</a></ul>
<li><a href=#changes><span class=secno></span> Changes</a>
<ul class=toc>
<li><a href=#changes-2012><span class=secno></span> Changes Since the Media Queries Level 3</a></ul>
<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>
<ul class=toc>
<li><a href=#media-descriptor-table><span class=secno></span> <span data-link-type=at-rule>@media</span> Descriptors</a></ul>
<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>HTML4 <a data-biblio-type=informative data-link-type=biblio href=#biblio-html401 title=biblio-html401>[HTML401]</a> defined a mechanism to support media-dependent style sheets,
tailored for different <a data-link-type=dfn href=#media-type title="media types">media types</a>.
For example, a document may use different style sheets for screen and for print.
In HTML, this can be written as:</p>
<div class=example>
<pre><link rel="stylesheet" type="text/css" media="screen" href="style.css">
<link rel="stylesheet" type="text/css" media="print" href="print.css">
</pre>
</div>
<p>CSS adapted and extended this functionality with its <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-conditional-3/#at-ruledef-media title=@media>@media</a> and <a class=css data-link-type=maybe href=http://www.w3.org/TR/css3-cascade/#at-ruledef-import title=@import>@import</a> rules,
adding the ability to query the value of individual features:</p>
<div class=example>
Inside a CSS style sheet,
one can declare that sections apply to certain <a data-link-type=dfn href=#media-type title="media types">media types</a>:
<pre>@media screen {
* { font-family: sans-serif }
}
</pre>
<p>Similarly, stylesheets can be conditionally imported based on media queries:</p>
<pre>@import "print-styles.css" print;</pre>
</div>
<p><a data-link-type=dfn href=#media-query title="media queries">Media queries</a> can be used with HTML, XHTML, XML <a data-biblio-type=informative data-link-type=biblio href=#biblio-xmlstyle title=biblio-xmlstyle>[XMLSTYLE]</a> and the @import and @media rules of CSS.</p>
<div class=example>
Here is the same example written in HTML, XHTML, XML, @import and @media:
<pre><link media="screen and (color), projection and (color)"
rel="stylesheet" href="example.css">
<link media="screen and (color), projection and (color)"
rel="stylesheet" href="example.css" />
<?xml-stylesheet media="screen and (color), projection and (color)"
rel="stylesheet" href="example.css" ?>
@import url(example.css) screen and (color), projection and (color);
@media screen and (color), projection and (color) { … }
</pre>
<p class=note>Note: The <a data-biblio-type=informative data-link-type=biblio href=#biblio-xmlstyle title=biblio-xmlstyle>[XMLSTYLE]</a> specification has not yet been updated to
use media queries in the <code>media</code> pseudo-attribute.</p>
</div>
<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 replaces and extends the Media Queries, Media Type and Media Features
defined in <a data-biblio-type=normative data-link-type=biblio href=#biblio-css21 title=biblio-css21>[CSS21]</a> sections 7 and in <a data-biblio-type=normative data-link-type=biblio href=#biblio-mediaq title=biblio-mediaq>[MEDIAQ]</a>.</p>
<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>Value types not defined in this specification, such as <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a>,
<a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-values/#number-value title="<number>"><number></a> or <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-values/#resolution-value title="<resolution>"><resolution></a>, are defined in <a data-biblio-type=normative data-link-type=biblio href=#biblio-css3val title=biblio-css3val>[CSS3VAL]</a>. Other CSS
modules may expand the definitions of these value types.</p>
<p>This specification also introduces some new value types.</p>
<p>The <dfn class=css-code data-dfn-type=type data-export="" id=typedef-ratio><ratio><a class=self-link href=#typedef-ratio></a></dfn> value type is a positive (not zero or negative)
<a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a> followed by optional whitespace, followed by a solidus ('/'),
followed by optional whitespace, followed by a positive <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a>.
<a class="production css-code" data-link-type=type href=#typedef-ratio title="<ratio>"><ratio></a>s can be ordered or compared by transforming them into the number
obtained by dividing their first <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a> by their second <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a>.</p>
<p class=issue id=issue-2ae5b8ca><a class=self-link href=#issue-2ae5b8ca></a>
Reasonable to restrict <a class="production css-code" data-link-type=type href=#typedef-ratio title="<ratio>"><ratio></a> to <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a>s?
I’ve seen aspect ratios written with decimal points in real life.
<p>The <dfn class=css-code data-dfn-type=type data-export="" id=typedef-mq-boolean><mq-boolean><a class=self-link href=#typedef-mq-boolean></a></dfn> value type is an <a class="production css-code" data-link-type=type href=http://www.w3.org/TR/css3-syntax/#typedef-integer title="<integer>"><integer></a>
with the value <span class=css data-link-type=maybe title=0>0</span> or <span class=css data-link-type=maybe title=1>1</span>.
Any other integer value is invalid.
<span class=note>Note that <span class=css data-link-type=maybe title=-0>-0</span> is always equivalent to <span class=css data-link-type=maybe title=0>0</span> in CSS,
and so is also accepted as a valid <a class="production css-code" data-link-type=type href=#typedef-mq-boolean title="<mq-boolean>"><mq-boolean></a> value.</span></p>
<h3 class="heading settled heading" data-level=1.3 id=units><span class=secno>1.3 </span><span class=content>
Units</span><a class=self-link href=#units></a></h3>
<p>The units used in media queries are the same as in other parts of CSS, as
defined in <a data-biblio-type=normative data-link-type=biblio href=#biblio-css3val title=biblio-css3val>[CSS3VAL]</a>. For example, the pixel unit represents CSS pixels and
not physical pixels.</p>
<p>Relative units in media queries are based on the initial value, which means
that units are never based on results of declarations. For example, in HTML,
the <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-values-3/#em title=em>em</a> unit is relative to the initial value of <a class=property data-link-type=propdesc href=http://www.w3.org/TR/css-fonts-3/#propdef-font-size title=font-size>font-size</a>,
defined by the user agent or the user’s preferences,
not any styling on the page.</p>
<h2 class="heading settled heading" data-level=2 id=media><span class=secno>2 </span><span class=content>
Media Queries</span><a class=self-link href=#media></a></h2>
<p>A <dfn data-dfn-type=dfn data-export="" id=media-query>media query<a class=self-link href=#media-query></a></dfn> is a method of testing certain aspects of the user agent
or device that the document is being displayed in.
<a data-link-type=dfn href=#media-query title="media queries">Media queries</a> are (almost) always independent of the contents of the document,
its styling,
or any other internal aspect;
they’re only dependent on “external” information
unless another feature explicitly specifies that it affects the resolution of Media Queries,
such as the <span class=css data-link-type=maybe title=@viewport>@viewport</span> rule.</p>
<p>The syntax of a <a data-link-type=dfn href=#media-query title="media query">media query</a> consists of
an optional <a data-link-type=dfn href=#media-query-modifier title="media query modifier">media query modifier</a>,
an optional <a data-link-type=dfn href=#media-type title="media type">media type</a>,
and zero or more <a data-link-type=dfn href=#media-feature title="media features">media features</a>:</p>
<div class=railroad><svg class=railroad-diagram height=191 viewBox="0 0 517 191" width=517>
<g transform="translate(.5 .5)">
<path d="M 20 31 v 20 m 10 -20 v 20 m -10 -10 h 20.5">
</path><g>
<path d="M40 41h0.0">
</path><path d="M476.0 41h0.0">
</path><path d="M40.0 41a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10">
</path><g>
<path d="M60.0 21h396">
</path></g><path d="M456.0 21a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10">
</path><path d="M40.0 41h20">
</path><g>
<path d="M60.0 41h74.0">
</path><path d="M382.0 41h74.0">
</path><g>
<path d="M134.0 41h0.0">
</path><path d="M218.0 41h0.0">
</path><path d="M134.0 41h20">
</path><g>
<path d="M154.0 41h44">
</path></g><path d="M198.0 41h20">
</path><path d="M134.0 41a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10">
</path><g>
<path d="M154.0 61h0.0">
</path><path d="M198.0 61h0.0">
</path><rect height=22 rx=10 ry=10 width=44 x=154.0 y=50>
</rect><text x=176.0 y=65>
not</text></g><path d="M198.0 61a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10">
</path></g><path d="M218.0 41h10">
</path><g>
<path d="M228.0 41h0.0">
</path><path d="M372.0 41h0.0">
</path><path d="M228.0 41h10">
</path><g>
<path d="M238.0 41h0.0">
</path><path d="M362.0 41h0.0">
</path><rect height=22 width=124 x=238.0 y=30>
</rect><text x=300.0 y=45>
media feature</text></g><path d="M362.0 41h10">
</path><path d="M238.0 41a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10">
</path><g>
<path d="M238.0 71h40.0">
</path><path d="M322.0 71h40.0">
</path><rect height=22 rx=10 ry=10 width=44 x=278.0 y=60>
</rect><text x=300.0 y=75>
and</text></g><path d="M362.0 71a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10">
</path></g><path d="M372.0 41h10">
</path></g><path d="M456.0 41h20">
</path><path d="M40.0 41a10 10 0 0 1 10 10v69a10 10 0 0 0 10 10">
</path><g>
<path d="M60.0 130h0.0">
</path><path d="M456.0 130h0.0">
</path><g>
<path d="M60.0 130h0.0">
</path><path d="M152.0 130h0.0">
</path><path d="M60.0 130a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10">
</path><g>
<path d="M80.0 110h0.0">
</path><path d="M132.0 110h0.0">
</path><rect height=22 rx=10 ry=10 width=52 x=80.0 y=99>
</rect><text x=106.0 y=114>
only</text></g><path d="M132.0 110a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10">
</path><path d="M60.0 130h20">
</path><g>
<path d="M80.0 130h52">
</path></g><path d="M132.0 130h20">
</path><path d="M60.0 130a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10">
</path><g>
<path d="M80.0 150h4.0">
</path><path d="M128.0 150h4.0">
</path><rect height=22 rx=10 ry=10 width=44 x=84.0 y=139>
</rect><text x=106.0 y=154>
not</text></g><path d="M132.0 150a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10">
</path></g><path d="M152.0 130h10">
</path><g>
<path d="M162.0 130h0.0">
</path><path d="M262.0 130h0.0">
</path><rect height=22 width=100 x=162.0 y=119>
</rect><text x=212.0 y=134>
media type</text></g><path d="M262.0 130h10">
</path><g>
<path d="M272.0 130h0.0">
</path><path d="M456.0 130h0.0">
</path><path d="M272.0 130a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10">
</path><g>
<path d="M292.0 110h144">
</path></g><path d="M436.0 110a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10">
</path><path d="M272.0 130h20">
</path><g>
<path d="M292.0 130h0.0">
</path><path d="M436.0 130h0.0">
</path><path d="M292.0 130h10">
</path><g>
<path d="M302.0 130h0.0">
</path><path d="M426.0 130h0.0">
</path><rect height=22 width=124 x=302.0 y=119>
</rect><text x=364.0 y=134>
media feature</text></g><path d="M426.0 130h10">
</path><path d="M302.0 130a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10">
</path><g>
<path d="M302.0 160h40.0">
</path><path d="M386.0 160h40.0">
</path><rect height=22 rx=10 ry=10 width=44 x=342.0 y=149>
</rect><text x=364.0 y=164>
and</text></g><path d="M426.0 160a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10">
</path></g><path d="M436.0 130h20">
</path></g></g><path d="M456.0 130a10 10 0 0 0 10 -10v-69a10 10 0 0 1 10 -10">
</path></g><path d="M 476 41 h 20 m -10 -10 v 20 m 10 -20 v 20">
</path></g></svg></div>
<p>A <a data-link-type=dfn href=#media-query title="media query">media query</a> is a logical expression that is either true or false.
A media query is true if:</p>
<ul>
<li>
the <a data-link-type=dfn href=#media-type title="media type">media type</a>,
if specified,
matches the media type of the device where the user agent is running, and
<li>
all specified <a data-link-type=dfn href=#media-feature title="media features">media features</a> are true.
</ul>
<p>Statements regarding media queries in this section assume the
<a href=#syntax>syntax section</a> is followed. Media queries that do not
conform to the syntax are discussed in the
<a href=#error-handling>error handling section</a>. I.e. the syntax takes
precedence over requirements in this section.</p>
<div class=example>
Here is a simple example written in HTML:
<pre><link rel="stylesheet" media="screen and (color)" href="example.css" /></pre>
<p>This example expresses that a certain style sheet
(<code>example.css</code>) applies to devices of a certain media type
(<a class=css data-link-type=maybe href=#valuedef-screen title=screen>screen</a>) with certain feature (it must be a color screen).</p>
<p>Here is the same media query written in an @import-rule in CSS:</p>
<pre>@import url(example.css) screen and (color);</pre>
</div>
<p>User agents should re-evaluate <a data-link-type=dfn href=#media-query title="media queries">media queries</a> in response to changes in the user environment,
for example if the device is tiled from landscape to portrait orientation,
and change the behavior of any constructs dependent on those <a data-link-type=dfn href=#media-query title="media queries">media queries</a> accordingly.</p>
<p>Unless another feature explicitly specifies that it affects the resolution of Media Queries, it is never necessary to apply a style sheet in order to evaluate expressions.</p>
<p class=note>Note: CSS Device Adaptation <a data-biblio-type=informative data-link-type=biblio href=#biblio-css-device-adapt title=biblio-css-device-adapt>[CSS-DEVICE-ADAPT]</a>]
defines how <span class=css data-link-type=maybe title=@viewport>@viewport</span> rules interact with Media Queries.</p>
<h3 class="heading settled heading" data-level=2.1 id=mq-list><span class=secno>2.1 </span><span class=content>
Combining Media Queries</span><a class=self-link href=#mq-list></a></h3>
<p>Several <a data-link-type=dfn href=#media-query title="media queries">media queries</a> can be combined into a comma-separated <dfn data-dfn-type=dfn data-export="" id=media-query-list>media query list<a class=self-link href=#media-query-list></a></dfn>.</p>
<div class=railroad><svg class=railroad-diagram height=102 viewBox="0 0 249 102" width=249>
<g transform="translate(.5 .5)">
<path d="M 20 31 v 20 m 10 -20 v 20 m -10 -10 h 20.5">
</path><g>
<path d="M40 41h0.0">
</path><path d="M208.0 41h0.0">
</path><path d="M40.0 41a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10">
</path><g>
<path d="M60.0 21h128">
</path></g><path d="M188.0 21a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10">
</path><path d="M40.0 41h20">
</path><g>
<path d="M60.0 41h0.0">
</path><path d="M188.0 41h0.0">
</path><path d="M60.0 41h10">
</path><g>
<path d="M70.0 41h0.0">
</path><path d="M178.0 41h0.0">
</path><rect height=22 width=108 x=70.0 y=30>
</rect><text x=124.0 y=45>
media query</text></g><path d="M178.0 41h10">
</path><path d="M70.0 41a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10">
</path><g>
<path d="M70.0 71h40.0">
</path><path d="M138.0 71h40.0">
</path><rect height=22 rx=10 ry=10 width=28 x=110.0 y=60>
</rect><text x=124.0 y=75>
,</text></g><path d="M178.0 71a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10">
</path></g><path d="M188.0 41h20">
</path></g><path d="M 208 41 h 20 m -10 -10 v 20 m 10 -20 v 20">
</path></g></svg></div>
<p>A <a data-link-type=dfn href=#media-query-list title="media query list">media query list</a> is true if <em>any</em> of its component <a data-link-type=dfn href=#media-query title="media queries">media queries</a> are true,
and false only if <em>all</em> of its component <a data-link-type=dfn href=#media-query title="media queries">media queries</a> are false.</p>
<div class=example>
For example, the following <a data-link-type=dfn href=#media-query-list title="media query list">media query list</a> is true if either
the <a data-link-type=dfn href=#media-type title="media type">media type</a> is <a class=css data-link-type=maybe href=#valuedef-screen title=screen>screen</a> and it’s a color device,
<strong>or</strong> the <a data-link-type=dfn href=#media-type title="media type">media type</a> is <a class=css data-link-type=maybe href=#valuedef-projection title=projection>projection</a> and it’s a color device:
<pre>@media screen and (color), projection and (color) { … }
</pre>
</div>
<p>An empty <a data-link-type=dfn href=#media-query-list title="media query list">media query list</a> evaluates to true.</p>
<div class=example>
For example, these are equivalent:
<pre>@media all { … }
@media { … }
</pre>
</div>
<h3 class="heading settled heading" data-level=2.2 id=mq-prefix><span class=secno>2.2 </span><span class=content>
Media Query Modifiers</span><a class=self-link href=#mq-prefix></a></h3>
<p>A <a data-link-type=dfn href=#media-query title="media query">media query</a> may optionally be prefixed by a single <dfn data-dfn-type=dfn data-export="" id=media-query-modifier>media query modifier<a class=self-link href=#media-query-modifier></a></dfn>,
which is a single keyword which alters the meaning of the following <a data-link-type=dfn href=#media-query title="media query">media query</a>.</p>
<h4 class="heading settled heading" data-level=2.2.1 id=mq-not><span class=secno>2.2.1 </span><span class=content>
Negating a Media Query: the <a class=css data-link-type=maybe href=#valuedef-not title=not>not</a> keyword</span><a class=self-link href=#mq-not></a></h4>
<p>An individual <a data-link-type=dfn href=#media-query title="media query">media query</a> can have its result negated
by prefixing it with the keyword <dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-not>not<a class=self-link href=#valuedef-not></a></dfn>.
If the <a data-link-type=dfn href=#media-query title="media query">media query</a> would normally evaluate to true,
prefixing it with <a class=css data-link-type=maybe href=#valuedef-not title=not>not</a> makes it evaluate to false,
and vice versa.</p>
<div class=example>
For example, the following will apply to everything except color-capable screens.
Note that the entire media query is negated,
not just the <a data-link-type=dfn href=#media-type title="media type">media type</a>.
<pre><link rel="stylesheet" media="not screen and (color)" href="example.css" /></pre>
</div>
<h4 class="heading settled heading" data-level=2.2.2 id=mq-only><span class=secno>2.2.2 </span><span class=content>
Hiding a Media Query From Legacy User Agents: the <a class=css data-link-type=maybe href=#valuedef-only title=only>only</a> keyword</span><a class=self-link href=#mq-only></a></h4>
<p>The concept of <a data-link-type=dfn href=#media-query title="media queries">media queries</a> originates from HTML4 <a data-biblio-type=informative data-link-type=biblio href=#biblio-html401 title=biblio-html401>[HTML401]</a>.
That specification only defined <a data-link-type=dfn href=#media-type title="media types">media types</a>,
but had a forward-compatible syntax that accommodated the addition of future concepts like <a data-link-type=dfn href=#media-feature title="media features">media features</a>:
it would consume the characters of a <a data-link-type=dfn href=#media-query title="media query">media query</a> up to the first non-alphanumeric character,
and interpret that as a <a data-link-type=dfn href=#media-type title="media type">media type</a>,
ignoring the rest.
For example, the <a data-link-type=dfn href=#media-query title="media query">media query</a> <span class=css data-link-type=maybe title="screen and (color)">screen and (color)</span>
would be truncated to just <a class=css data-link-type=maybe href=#valuedef-screen title=screen>screen</a>.</p>
<p>Unfortunately, this means that legacy user agents using this error-handling behavior
will ignore any <a data-link-type=dfn href=#media-feature title="media features">media features</a> in a <a data-link-type=dfn href=#media-query title="media query">media query</a>,
even if they’re far more important than the <a data-link-type=dfn href=#media-type title="media type">media type</a> in the query.
This can result in styles accidentally being applied in inappropriate situations.</p>
<p>To hide these <a data-link-type=dfn href=#media-query title="media queries">media queries</a> from legacy user agents,
the <a data-link-type=dfn href=#media-query title="media query">media query</a> can be prefixed with the keyword <dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-only>only<a class=self-link href=#valuedef-only></a></dfn>.
The <a class=css data-link-type=maybe href=#valuedef-only title=only>only</a> keyword <strong>has no effect</strong> on the <a data-link-type=dfn href=#media-query title="media query">media query</a>’s result,
but will cause the <a data-link-type=dfn href=#media-query title="media query">media query</a> to be parsed by legacy user agents
as specifying the unknown <a data-link-type=dfn href=#media-type title="media type">media type</a> “only”,
and thus be ignored.</p>
<div class=example>
In this example, the stylesheet specified by the <code><link></code> element
will not be used by legacy user agents,
even if they would normally match the <a class=css data-link-type=maybe href=#valuedef-screen title=screen>screen</a> <a data-link-type=dfn href=#media-type title="media type">media type</a>.
<pre><link rel="stylesheet" media="only screen and (color)" href="example.css" /></pre>
</div>
<p class=note>Note: Note that the <a class=css data-link-type=maybe href=#valuedef-only title=only>only</a> keyword can only be used before a <a data-link-type=dfn href=#media-type title="media type">media type</a>.
A <a data-link-type=dfn href=#media-query title="media query">media query</a> consisting only of <a data-link-type=dfn href=#media-feature title="media features">media features</a>,
or one with another <a data-link-type=dfn href=#media-query-modifier title="media query modifier">media query modifier</a> like <a class=css data-link-type=maybe href=#valuedef-not title=not>not</a>,
will be treated as false by legacy user agents automatically.</p>
<p class=note>Note: At the time of publishing this specification,
such legacy user agents are extremely rare,
and so using the <a class=css data-link-type=maybe href=#valuedef-only title=only>only</a> modifier is rarely, if ever, necessary.</p>
<h3 class="heading settled heading" data-level=2.3 id=media-types><span class=secno>2.3 </span><span class=content>
Media Types</span><a class=self-link href=#media-types></a></h3>
<p>A <dfn data-dfn-type=dfn data-export="" id=media-type>media type<a class=self-link href=#media-type></a></dfn> is a broad category of user-agent devices
on which a document may be displayed.
The original set of <a data-link-type=dfn href=#media-type title="media types">media types</a> were defined in HTML4,
for the <code>media</code> attribute on <code><link></code> elements.</p>
<p>Unfortunately, <a data-link-type=dfn href=#media-type title="media types">media types</a> have proven insufficient as a way of discriminating between devices with different styling needs.
Some categories which were originally quite distinct,
such as <a class=css data-link-type=maybe href=#valuedef-screen title=screen>screen</a> and <a class=css data-link-type=maybe href=#valuedef-handheld title=handheld>handheld</a>,
have blended significantly in the years since their invention.
Others, such as <a class=css data-link-type=maybe href=#valuedef-tty title=tty>tty</a> or <a class=css data-link-type=maybe href=#valuedef-tv title=tv>tv</a>,
expose useful differences from the norm of a full-featured computer monitor,
and so are potentially useful to target with different styling,
but the definition of <a data-link-type=dfn href=#media-type title="media types">media types</a> as mutually exclusive
makes it difficult to use them in a reasonable manner;
instead, their exclusive aspects are better expressed as <a data-link-type=dfn href=#media-feature title="media features">media features</a>
such as <a class=property data-link-type=propdesc href=#descdef-grid title=grid>grid</a> or <a class=property data-link-type=propdesc href=#descdef-scan title=scan>scan</a>.</p>
<p>As such, the following <a data-link-type=dfn href=#media-type title="media types">media types</a> are defined for use in <a data-link-type=dfn href=#media-query title="media queries">media queries</a>:</p>
<dl data-dfn-for=@media data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-all>all<a class=self-link href=#valuedef-all></a></dfn>
<dd>Matches all devices.
<dt><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-print>print<a class=self-link href=#valuedef-print></a></dfn>
<dd>Matches printers, and devices intended to reproduce a printed display,
such as a web browser showing a document in “Print Preview”.
<dt><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-screen>screen<a class=self-link href=#valuedef-screen></a></dfn>
<dd>Matches all devices that aren’t matched by <a class=css data-link-type=maybe href=#valuedef-print title=print>print</a> or <a class=css data-link-type=maybe href=#valuedef-speech title=speech>speech</a>.
<dt><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-speech>speech<a class=self-link href=#valuedef-speech></a></dfn>
<dd>Matches screenreaders and similar devices that “read out” a page.
</dl>
<p>In addition, the following <strong>deprecated</strong> <a data-link-type=dfn href=#media-type title="media types">media types</a> are defined.
Authors must not use these <a data-link-type=dfn href=#media-type title="media types">media types</a>;
instead, it is recommended that they select appropriate <a data-link-type=dfn href=#media-feature title="media features">media features</a>
that better represent the aspect of the device that they are attempting to style against.</p>
<p>User agents must recognize the following <a data-link-type=dfn href=#media-type title="media types">media types</a> as valid,
but must make them match nothing.</p>
<ul data-dfn-for=@media data-dfn-type=value>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-tty>tty<a class=self-link href=#valuedef-tty></a></dfn>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-tv>tv<a class=self-link href=#valuedef-tv></a></dfn>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-projection>projection<a class=self-link href=#valuedef-projection></a></dfn>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-handheld>handheld<a class=self-link href=#valuedef-handheld></a></dfn>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-braille>braille<a class=self-link href=#valuedef-braille></a></dfn>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-embossed>embossed<a class=self-link href=#valuedef-embossed></a></dfn>
<li><dfn class=css-code data-dfn-for=@media data-dfn-type=value data-export="" id=valuedef-aural>aural<a class=self-link href=#valuedef-aural></a></dfn>
</ul>
<p class=note>Note: It is expected that all of the media types will also be deprecated in time,
as appropriate <a data-link-type=dfn href=#media-feature title="media features">media features</a> are defined which capture their important differences.</p>
<h3 class="heading settled heading" data-level=2.4 id=mq-features><span class=secno>2.4 </span><span class=content>
Media Features</span><a class=self-link href=#mq-features></a></h3>
<p>A <dfn data-dfn-type=dfn data-export="" id=media-feature>media feature<a class=self-link href=#media-feature></a></dfn> is a more fine-grained test than <a data-link-type=dfn href=#media-type title="media types">media types</a>,
testing a single, specific feature of the user agent or display device.</p>
<p>Syntactically, <a data-link-type=dfn href=#media-feature title="media features">media features</a> resemble CSS properties:
they consist of a feature name, a colon, and a value to test for.
They may also be written in boolean form as just a feature name,
or in range form with a comparison operator.</p>
<div class=railroad><svg class=railroad-diagram height=122 viewBox="0 0 545 122" width=545>
<g transform="translate(.5 .5)">
<path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5">
</path><path d="M40 31h10">
</path><g>
<path d="M50 31h0.0">
</path><path d="M78.0 31h0.0">
</path><rect height=22 rx=10 ry=10 width=28 x=50.0 y=20>
</rect><text x=64.0 y=35>
(</text></g><path d="M78 31h10">
</path><g>
<path d="M88 31h0.0">
</path><path d="M456.0 31h0.0">
</path><path d="M88.0 31h20">
</path><g>
<path d="M108.0 31h0.0">
</path><path d="M436.0 31h0.0">
</path><path d="M108.0 31h10">
</path><g>
<path d="M118.0 31h0.0">
</path><path d="M234.0 31h0.0">
</path><rect height=22 width=116 x=118.0 y=20>
</rect><text x=176.0 y=35>
feature name</text></g><path d="M234.0 31h10">
</path><path d="M244.0 31h10">
</path><g>
<path d="M254.0 31h0.0">
</path><path d="M282.0 31h0.0">
</path><rect height=22 rx=10 ry=10 width=28 x=254.0 y=20>
</rect><text x=268.0 y=35>
:</text></g><path d="M282.0 31h10">
</path><path d="M292.0 31h10">
</path><g>
<path d="M302.0 31h0.0">
</path><path d="M426.0 31h0.0">
</path><rect height=22 width=124 x=302.0 y=20>
</rect><text x=364.0 y=35>
feature value</text></g><path d="M426.0 31h10">
</path></g><path d="M436.0 31h20">
</path><path d="M88.0 31a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10">
</path><g>
<path d="M108.0 61h106.0">
</path><path d="M330.0 61h106.0">
</path><rect height=22 width=116 x=214.0 y=50>
</rect><text x=272.0 y=65>
feature name</text></g><path d="M436.0 61a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10">
</path><path d="M88.0 31a10 10 0 0 1 10 10v40a10 10 0 0 0 10 10">
</path><g>
<path d="M108.0 91h50.5">
</path><path d="M385.5 91h50.5">
</path><path d="M158.5 91h10">
</path><g>
<path d="M168.5 91h0.0">
</path><path d="M268.5 91h0.0">
</path><rect height=22 width=100 x=168.5 y=80>
</rect><text x=218.5 y=95>
range form</text></g><path d="M268.5 91h10">
</path><path d="M278.5 91h10">
</path><g>
<path d="M288.5 91h0.0">
</path><path d="M375.5 91h0.0">
</path><text class=comment x=332.0 y=96>
(see below)</text></g><path d="M375.5 91h10">
</path></g><path d="M436.0 91a10 10 0 0 0 10 -10v-40a10 10 0 0 1 10 -10">
</path></g><path d="M456 31h10">
</path><g>
<path d="M466 31h0.0">
</path><path d="M494.0 31h0.0">
</path><rect height=22 rx=10 ry=10 width=28 x=466.0 y=20>
</rect><text x=480.0 y=35>
)</text></g><path d="M494 31h10">
</path><path d="M 504 31 h 20 m -10 -10 v 20 m 10 -20 v 20">
</path></g></svg></div>
<p>There are, however, several important differences between properties and media features:</p>
<ul>
<li>
Properties are used to give information about how to present a document.
Media features are used to describe requirements of the output device.
<li>
Media features are always wrapped in parentheses
and combined with the <span class=css data-link-type=maybe title=and>and</span> keyword,
like <span class=css data-link-type=maybe title="(color) and (min-width: 600px)">(color) and (min-width: 600px)</span>,
rather than being separated with semicolons.
<li>
A media feature may be given with <em>only</em> its name
(omitting the colon and value)
to evaluate the feature in a <a data-link-type=dfn href=#boolean-context title="boolean context">boolean context</a>.
This is a convenient shorthand for features that have a reasonable value representing 0 or “none”.
For example, <span class=css data-link-type=maybe title=(color)>(color)</span> is true is the <a class=property data-link-type=propdesc href=#descdef-color title=color>color</a> <a data-link-type=dfn href=#media-feature title="media feature">media feature</a> is non-zero.
<li>
<a data-link-type=dfn href=#media-feature title="media features">Media features</a> with “range” type can be written in a <a data-link-type=dfn href=#range-context title="range context">range context</a>,
which uses standard mathematical comparison operators rather than a colon,
or have their feature names <a href=#mq-min-max>prefixed with “min-” or “max-”</a>.
<li>
Properties sometimes accept complex values,
e.g., calculations that involve several other values.
<a data-link-type=dfn href=#media-feature title="media features">Media features</a> only accept single values: one keyword, one number, etc.
</ul>
<p>If a media feature does not apply to the device where the UA is running,
that <a data-link-type=dfn href=#media-feature title="media feature">media feature</a> will always be false.</p>
<div class=example>
The media feature <span class=css data-link-type=maybe title=device-aspect-ratio>device-aspect-ratio</span> only applies to
visual devices. On an <a class=css data-link-type=maybe href=#valuedef-speech title=speech>speech</a> device, expressions involving
<span class=css data-link-type=maybe title=device-aspect-ratio>device-aspect-ratio</span> will therefore always be false:
<pre><link media="speech and (device-aspect-ratio: 16/9)"
rel="stylesheet" href="example.css">
</pre>
</div>
<h4 class="heading settled heading" data-level=2.4.1 id=mq-ranges><span class=secno>2.4.1 </span><span class=content>
Media Feature Types: “range” and “discrete”</span><a class=self-link href=#mq-ranges></a></h4>
<p>Every media feature defines its “type” as either “range” or “discrete” in its definition table.</p>
<p>“Discrete” media features,
like <a class=property data-link-type=propdesc href=#descdef-light-level title=light-level>light-level</a> or <a class=property data-link-type=propdesc href=#descdef-scripting title=scripting>scripting</a>,
take their values from a set.
The values may be keywords
or boolean numbers (0 and 1),
but the common factor is that there’s no intrinsic “order” to them—<wbr>none of the values are “less than” or “greater than” each other.</p>
<p>“Range” media features like <a class=property data-link-type=propdesc href=#descdef-width title=width>width</a>, on the other hand,
take their values from a range.
Any two values can be compared to see which is lesser and which is greater.</p>
<p>The only significant difference between the two types is that “range” <a data-link-type=dfn href=#media-feature title="media features">media features</a>
can be evaluated in a <a data-link-type=dfn href=#range-context title="range context">range context</a>
and accept “min-” and “max-” prefixes on their name.
Doing either of these changes the meaning of the feature—<wbr>rather than the <a data-link-type=dfn href=#media-feature title="media feature">media feature</a> being true when the feature exactly matches the given value,
it matches when the feature is greater than/less than/equal to the given value.</p>
<div class=example>
A <span class=css data-link-type=maybe>(width >= 600px)</span> <a data-link-type=dfn href=#media-feature title="media feature">media feature</a> is true
when the viewport’s width is <span class=css data-link-type=maybe title=600px>600px</span> <em>or more</em>.
<p>On the other hand, <span class=css data-link-type=maybe title="(width: 600px)">(width: 600px)</span> by itself is only true
when the viewport’s width is <em>exactly</em> <span class=css data-link-type=maybe title=600px>600px</span>.
If it’s less or greater than <span class=css data-link-type=maybe title=600px>600px</span>, it’ll be false.</p>
</div>
<h4 class="heading settled heading" data-level=2.4.2 id=mq-boolean-context><span class=secno>2.4.2 </span><span class=content>
Evaluating Media Features in a Boolean Context</span><a class=self-link href=#mq-boolean-context></a></h4>
<p>While <a data-link-type=dfn href=#media-feature title="media features">media features</a> normally have a syntax similar to CSS properties,
they can also be written more simply as just the feature name,
like <span class=css data-link-type=maybe title=(color)>(color)</span>.</p>
<p>When written like this, the <a data-link-type=dfn href=#media-feature title="media feature">media feature</a> is evaluated in a <dfn data-dfn-type=dfn data-export="" id=boolean-context>boolean context<a class=self-link href=#boolean-context></a></dfn>.
If the feature would be true for the number <span class=css data-link-type=maybe title=0>0</span>,
a dimension with the value <span class=css data-link-type=maybe title=0>0</span>,
or the keyword <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>,
the <a data-link-type=dfn href=#media-feature title="media feature">media feature</a> evaluates to false.
If it would be true for any values <strong>other than</strong> the above,
it evaluates to true.
Otherwise, it evaluates to false.</p>
<p class=note>Note: The “trichotomy” above allows for correct handling of MQs as false when on devices where they don’t apply at all,
such as <a class=property data-link-type=propdesc href=#descdef-scan title=scan>scan</a> on a speech device.</p>
<div class=example>
Some <a data-link-type=dfn href=#media-feature title="media features">media features</a> are designed to be written like this.
<p>For example, <a class=property data-link-type=propdesc href=#descdef-scripting title=scripting>scripting</a> is typically written as <span class=css data-link-type=maybe title=(scripting)>(scripting)</span> to test if scripting is enabled,
or <span class=css data-link-type=maybe title="not (scripting)">not (scripting)</span> to see if it’s disabled.</p>
<p>It can still be given an explicit value as well,
with <span class=css data-link-type=maybe title="(scripting: enabled)">(scripting: enabled)</span> equal to <span class=css data-link-type=maybe title=(scripting)>(scripting)</span>,
and <span class=css data-link-type=maybe title="(scripting: none)">(scripting: none)</span> equal to <span class=css data-link-type=maybe title="not (scripting)">not (scripting)</span>.</p>
</div>
<div class=example>
Some numeric <a data-link-type=dfn href=#media-feature title="media features">media features</a>, like <a class=property data-link-type=propdesc href=#descdef-width title=width>width</a>,
are rarely if ever useful to evaluate in a <a data-link-type=dfn href=#boolean-context title="boolean context">boolean context</a>,
as their values are almost always greater than zero.
Others, like <a class=property data-link-type=propdesc href=#descdef-color title=color>color</a>, have meaningful zero values:
<span class=css data-link-type=maybe title=(color)>(color)</span> is identical to <span class=css data-link-type=maybe title="(color > 0)">(color > 0)</span>,
indicating that the device is capable of displaying color at all.
</div>
<div class=example>
Only some of the <a data-link-type=dfn href=#media-feature title="media features">media features</a> that accept keywords are meaningful in a <a data-link-type=dfn href=#boolean-context title="boolean context">boolean context</a>.
<p>For example, <span class=css data-link-type=maybe title=(pointer)>(pointer)</span> is useful,
as <a class=property data-link-type=propdesc href=#descdef-pointer title=pointer>pointer</a> has a <a class=css data-link-for=pointer data-link-type=maybe href=#valuedef-none3 title=none>none</a> value to indicate there’s no pointing device at all on the device.
On the other hand, <span class=css data-link-type=maybe title=(scan)>(scan)</span> is just always true or always false
(depending on whether it applies at all to the device),
as there’s no value that means “false”.</p>
</div>
<h4 class="heading settled heading" data-level=2.4.3 id=mq-range-context><span class=secno>2.4.3 </span><span class=content>
Evaluating Media Features in a Range Context</span><a class=self-link href=#mq-range-context></a></h4>
<p><a data-link-type=dfn href=#media-feature title="media features">Media features</a> with a “range” type can be alternately written in a <dfn data-dfn-type=dfn data-export="" id=range-context>range context<a class=self-link href=#range-context></a></dfn>
that takes advantage of the fact that their values are ordered,
using ordinary mathematical comparison operators:</p>
<div class=railroad><svg class=railroad-diagram height=302 viewBox="0 0 665 302" width=665>
<g transform="translate(.5 .5)">
<path d="M 20 141 v 20 m 10 -20 v 20 m -10 -10 h 20.5">
</path><path d="M40 151h10">
</path><g>
<path d="M50 151h0.0">
</path><path d="M78.0 151h0.0">
</path><rect height=22 rx=10 ry=10 width=28 x=50.0 y=140>
</rect><text x=64.0 y=155>
(</text></g><path d="M78 151h10">
</path><g>
<path d="M88 151h0.0">
</path><path d="M576.0 151h0.0">
</path><path d="M88.0 151h20">
</path><g>
<path d="M108.0 151h2.0">
</path><path d="M554.0 151h2.0">
</path><path d="M110.0 151h10">
</path><g>
<path d="M120.0 151h0.0">
</path><path d="M284.0 151h0.0">
</path><rect height=22 width=164 x=120.0 y=140>
</rect><text x=202.0 y=155>
feature name/value</text></g><path d="M284.0 151h10">
</path><g>
<path d="M294.0 151h0.0">
</path><path d="M370.0 151h0.0">
</path><path d="M294.0 151a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10">
</path><g>
<path d="M314.0 121h4.0">
</path><path d="M346.0 121h4.0">
</path><rect height=22 rx=10 ry=10 width=28 x=318.0 y=110>
</rect><text x=332.0 y=125>
></text></g><path d="M350.0 121a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10">
</path><path d="M294.0 151a10 10 0 0 0 10 -10v-40a10 10 0 0 1 10 -10">
</path><g>
<path d="M314.0 91h0.0">
</path><path d="M350.0 91h0.0">
</path><rect height=22 rx=10 ry=10 width=36 x=314.0 y=80>
</rect><text x=332.0 y=95>
<=</text></g><path d="M350.0 91a10 10 0 0 1 10 10v40a10 10 0 0 0 10 10">
</path><path d="M294.0 151a10 10 0 0 0 10 -10v-70a10 10 0 0 1 10 -10">
</path><g>
<path d="M314.0 61h4.0">
</path><path d="M346.0 61h4.0">
</path><rect height=22 rx=10 ry=10 width=28 x=318.0 y=50>
</rect><text x=332.0 y=65>
<</text></g><path d="M350.0 61a10 10 0 0 1 10 10v70a10 10 0 0 0 10 10">
</path><path d="M294.0 151a10 10 0 0 0 10 -10v-100a10 10 0 0 1 10 -10">
</path><g>
<path d="M314.0 31h4.0">
</path><path d="M346.0 31h4.0">
</path><rect height=22 rx=10 ry=10 width=28 x=318.0 y=20>
</rect><text x=332.0 y=35>
=</text></g><path d="M350.0 31a10 10 0 0 1 10 10v100a10 10 0 0 0 10 10">
</path><path d="M294.0 151h20">
</path><g>
<path d="M314.0 151h0.0">
</path><path d="M350.0 151h0.0">
</path><rect height=22 rx=10 ry=10 width=36 x=314.0 y=140>
</rect><text x=332.0 y=155>
>=</text></g><path d="M350.0 151h20">
</path></g><path d="M370.0 151h10">
</path><g>
<path d="M380.0 151h0.0">
</path><path d="M544.0 151h0.0">
</path><rect height=22 width=164 x=380.0 y=140>
</rect><text x=462.0 y=155>
feature value/name</text></g><path d="M544.0 151h10">
</path></g><path d="M556.0 151h20">
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