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<!doctype html>
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<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="description" content="Components and options for laying out your Bootstrap project, including wrapping containers, a powerful grid system, a flexible media object, and responsive utility classes.">
<meta name="author" content="Mark Otto, Jacob Thornton, and Bootstrap contributors">
<meta name="generator" content="Jekyll v4.1.1">
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<a class="btn btn-bd-download d-none d-lg-inline-block mb-3 mb-md-0 ml-md-3" href="/docs/4.5/getting-started/download/">Download</a>
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<div class="container-fluid">
<div class="row flex-xl-nowrap">
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<form role="search" class="bd-search d-flex align-items-center">
<input type="search" class="form-control" id="search-input" placeholder="Search..." aria-label="Search for..." autocomplete="off" data-docs-version="4.5">
<button class="btn bd-search-docs-toggle d-md-none p-0 ml-3" type="button" data-toggle="collapse" data-target="#bd-docs-nav" aria-controls="bd-docs-nav" aria-expanded="false" aria-label="Toggle docs navigation"><svg xmlns="http://www.w3.org/2000/svg" width="30" height="30" viewBox="0 0 30 30" role="img" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-linecap="round" stroke-miterlimit="10" stroke-width="2" d="M4 7h22M4 15h22M4 23h22"/></svg></button>
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<nav class="collapse bd-links" id="bd-docs-nav" aria-label="Main navigation"><div class="bd-toc-item">
<a class="bd-toc-link" href="/docs/4.5/getting-started/introduction/">
Getting started
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<a href="/docs/4.5/getting-started/introduction/">
Introduction
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<a href="/docs/4.5/getting-started/download/">
Download
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<a href="/docs/4.5/getting-started/contents/">
Contents
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<a href="/docs/4.5/getting-started/browsers-devices/">
Browsers & devices
</a>
</li><li>
<a href="/docs/4.5/getting-started/javascript/">
JavaScript
</a>
</li><li>
<a href="/docs/4.5/getting-started/theming/">
Theming
</a>
</li><li>
<a href="/docs/4.5/getting-started/build-tools/">
Build tools
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</li><li>
<a href="/docs/4.5/getting-started/webpack/">
Webpack
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<a href="/docs/4.5/getting-started/accessibility/">
Accessibility
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<a class="bd-toc-link" href="/docs/4.5/layout/overview/">
Layout
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<ul class="nav bd-sidenav"><li class="active bd-sidenav-active">
<a href="/docs/4.5/layout/overview/">
Overview
</a>
</li><li>
<a href="/docs/4.5/layout/grid/">
Grid
</a>
</li><li>
<a href="/docs/4.5/layout/utilities-for-layout/">
Utilities for layout
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<a class="bd-toc-link" href="/docs/4.5/content/reboot/">
Content
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<ul class="nav bd-sidenav"><li>
<a href="/docs/4.5/content/reboot/">
Reboot
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</li><li>
<a href="/docs/4.5/content/typography/">
Typography
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<a href="/docs/4.5/content/code/">
Code
</a>
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<a href="/docs/4.5/content/images/">
Images
</a>
</li><li>
<a href="/docs/4.5/content/tables/">
Tables
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<a href="/docs/4.5/content/figures/">
Figures
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<a class="bd-toc-link" href="/docs/4.5/components/alerts/">
Components
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<ul class="nav bd-sidenav"><li>
<a href="/docs/4.5/components/alerts/">
Alerts
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</li><li>
<a href="/docs/4.5/components/badge/">
Badge
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</li><li>
<a href="/docs/4.5/components/breadcrumb/">
Breadcrumb
</a>
</li><li>
<a href="/docs/4.5/components/buttons/">
Buttons
</a>
</li><li>
<a href="/docs/4.5/components/button-group/">
Button group
</a>
</li><li>
<a href="/docs/4.5/components/card/">
Card
</a>
</li><li>
<a href="/docs/4.5/components/carousel/">
Carousel
</a>
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<a href="/docs/4.5/components/collapse/">
Collapse
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<a href="/docs/4.5/components/dropdowns/">
Dropdowns
</a>
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<a href="/docs/4.5/components/forms/">
Forms
</a>
</li><li>
<a href="/docs/4.5/components/input-group/">
Input group
</a>
</li><li>
<a href="/docs/4.5/components/jumbotron/">
Jumbotron
</a>
</li><li>
<a href="/docs/4.5/components/list-group/">
List group
</a>
</li><li>
<a href="/docs/4.5/components/media-object/">
Media object
</a>
</li><li>
<a href="/docs/4.5/components/modal/">
Modal
</a>
</li><li>
<a href="/docs/4.5/components/navs/">
Navs
</a>
</li><li>
<a href="/docs/4.5/components/navbar/">
Navbar
</a>
</li><li>
<a href="/docs/4.5/components/pagination/">
Pagination
</a>
</li><li>
<a href="/docs/4.5/components/popovers/">
Popovers
</a>
</li><li>
<a href="/docs/4.5/components/progress/">
Progress
</a>
</li><li>
<a href="/docs/4.5/components/scrollspy/">
Scrollspy
</a>
</li><li>
<a href="/docs/4.5/components/spinners/">
Spinners
</a>
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<a href="/docs/4.5/components/toasts/">
Toasts
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<a href="/docs/4.5/components/tooltips/">
Tooltips
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<a class="bd-toc-link" href="/docs/4.5/utilities/borders/">
Utilities
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<ul class="nav bd-sidenav"><li>
<a href="/docs/4.5/utilities/borders/">
Borders
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<a href="/docs/4.5/utilities/clearfix/">
Clearfix
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<a href="/docs/4.5/utilities/close-icon/">
Close icon
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<a href="/docs/4.5/utilities/colors/">
Colors
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<a href="/docs/4.5/utilities/display/">
Display
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<a href="/docs/4.5/utilities/embed/">
Embed
</a>
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<a href="/docs/4.5/utilities/flex/">
Flex
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<a href="/docs/4.5/utilities/float/">
Float
</a>
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<a href="/docs/4.5/utilities/image-replacement/">
Image replacement
</a>
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<a href="/docs/4.5/utilities/interactions/">
Interactions
</a>
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<a href="/docs/4.5/utilities/overflow/">
Overflow
</a>
</li><li>
<a href="/docs/4.5/utilities/position/">
Position
</a>
</li><li>
<a href="/docs/4.5/utilities/screen-readers/">
Screen readers
</a>
</li><li>
<a href="/docs/4.5/utilities/shadows/">
Shadows
</a>
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<a href="/docs/4.5/utilities/sizing/">
Sizing
</a>
</li><li>
<a href="/docs/4.5/utilities/spacing/">
Spacing
</a>
</li><li>
<a href="/docs/4.5/utilities/stretched-link/">
Stretched link
</a>
</li><li>
<a href="/docs/4.5/utilities/text/">
Text
</a>
</li><li>
<a href="/docs/4.5/utilities/vertical-align/">
Vertical align
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<a href="/docs/4.5/utilities/visibility/">
Visibility
</a>
</li></ul>
</div><div class="bd-toc-item">
<a class="bd-toc-link" href="/docs/4.5/extend/approach/">
Extend
</a>
<ul class="nav bd-sidenav"><li>
<a href="/docs/4.5/extend/approach/">
Approach
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</li><li>
<a href="/docs/4.5/extend/icons/">
Icons
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</li></ul>
</div><div class="bd-toc-item">
<a class="bd-toc-link" href="/docs/4.5/migration/">
Migration
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<ul class="nav bd-sidenav"></ul>
</div><div class="bd-toc-item">
<a class="bd-toc-link" href="/docs/4.5/about/overview/">
About
</a>
<ul class="nav bd-sidenav"><li>
<a href="/docs/4.5/about/overview/">
Overview
</a>
</li><li>
<a href="/docs/4.5/about/team/">
Team
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<a href="/docs/4.5/about/brand/">
Brand
</a>
</li><li>
<a href="/docs/4.5/about/license/">
License
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</li><li>
<a href="/docs/4.5/about/translations/">
Translations
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</li></ul>
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</div>
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<ul class="section-nav">
<li class="toc-entry toc-h2"><a href="#containers">Containers</a>
<ul>
<li class="toc-entry toc-h3"><a href="#all-in-one">All-in-one</a></li>
<li class="toc-entry toc-h3"><a href="#fluid">Fluid</a></li>
<li class="toc-entry toc-h3"><a href="#responsive">Responsive</a></li>
</ul>
</li>
<li class="toc-entry toc-h2"><a href="#responsive-breakpoints">Responsive breakpoints</a></li>
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<a class="btn btn-sm btn-bd-light my-2 my-md-0" href="https://github.com/twbs/bootstrap/tree/v4-dev/site/docs/4.5/layout/overview.md" title="View and edit this file on GitHub" target="_blank" rel="noopener">View on GitHub</a>
<h1 class="bd-title" id="content">Overview</h1>
</div>
<p class="bd-lead">Components and options for laying out your Bootstrap project, including wrapping containers, a powerful grid system, a flexible media object, and responsive utility classes.</p>
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<h2 id="containers">Containers</h2>
<p>Containers are the most basic layout element in Bootstrap and are <strong>required when using our default grid system</strong>. Containers are used to contain, pad, and (sometimes) center the content within them. While containers <em>can</em> be nested, most layouts do not require a nested container.</p>
<p>Bootstrap comes with three different containers:</p>
<ul>
<li><code class="language-plaintext highlighter-rouge">.container</code>, which sets a <code class="language-plaintext highlighter-rouge">max-width</code> at each responsive breakpoint</li>
<li><code class="language-plaintext highlighter-rouge">.container-fluid</code>, which is <code class="language-plaintext highlighter-rouge">width: 100%</code> at all breakpoints</li>
<li><code class="language-plaintext highlighter-rouge">.container-{breakpoint}</code>, which is <code class="language-plaintext highlighter-rouge">width: 100%</code> until the specified breakpoint</li>
</ul>
<p>The table below illustrates how each containers <code class="language-plaintext highlighter-rouge">max-width</code> compares to the original <code class="language-plaintext highlighter-rouge">.container</code> and <code class="language-plaintext highlighter-rouge">.container-fluid</code> across each breakpoint.</p>
<p>See them in action and compare them in our <a href="/docs/4.5/examples/grid/#containers">Grid example</a>.</p>
<table class="table text-left">
<thead>
<tr>
<th></th>
<th>
Extra small<br />
<span class="font-weight-normal">&lt;576px</span>
</th>
<th>
Small<br />
<span class="font-weight-normal">&ge;576px</span>
</th>
<th>
Medium<br />
<span class="font-weight-normal">&ge;768px</span>
</th>
<th>
Large<br />
<span class="font-weight-normal">&ge;992px</span>
</th>
<th>
Extra large<br />
<span class="font-weight-normal">&ge;1200px</span>
</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>.container</code></td>
<td class="text-muted">100%</td>
<td>540px</td>
<td>720px</td>
<td>960px</td>
<td>1140px</td>
</tr>
<tr>
<td><code>.container-sm</code></td>
<td class="text-muted">100%</td>
<td>540px</td>
<td>720px</td>
<td>960px</td>
<td>1140px</td>
</tr>
<tr>
<td><code>.container-md</code></td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td>720px</td>
<td>960px</td>
<td>1140px</td>
</tr>
<tr>
<td><code>.container-lg</code></td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td>960px</td>
<td>1140px</td>
</tr>
<tr>
<td><code>.container-xl</code></td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td>1140px</td>
</tr>
<tr>
<td><code>.container-fluid</code></td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
<td class="text-muted">100%</td>
</tr>
</tbody>
</table>
<h3 id="all-in-one">All-in-one</h3>
<p>Our default <code class="language-plaintext highlighter-rouge">.container</code> class is a responsive, fixed-width container, meaning its <code class="language-plaintext highlighter-rouge">max-width</code> changes at each breakpoint.</p>
<figure class="highlight"><pre><code class="language-html" data-lang="html"><span class="nt">&lt;div</span> <span class="na">class=</span><span class="s">"container"</span><span class="nt">&gt;</span>
<span class="c">&lt;!-- Content here --&gt;</span>
<span class="nt">&lt;/div&gt;</span></code></pre></figure>
<h3 id="fluid">Fluid</h3>
<p>Use <code class="language-plaintext highlighter-rouge">.container-fluid</code> for a full width container, spanning the entire width of the viewport.</p>
<figure class="highlight"><pre><code class="language-html" data-lang="html"><span class="nt">&lt;div</span> <span class="na">class=</span><span class="s">"container-fluid"</span><span class="nt">&gt;</span>
...
<span class="nt">&lt;/div&gt;</span></code></pre></figure>
<h3 id="responsive">Responsive</h3>
<p>Responsive containers are new in Bootstrap v4.4. They allow you to specify a class that is 100% wide until the specified breakpoint is reached, after which we apply <code class="language-plaintext highlighter-rouge">max-width</code>s for each of the higher breakpoints. For example, <code class="language-plaintext highlighter-rouge">.container-sm</code> is 100% wide to start until the <code class="language-plaintext highlighter-rouge">sm</code> breakpoint is reached, where it will scale up with <code class="language-plaintext highlighter-rouge">md</code>, <code class="language-plaintext highlighter-rouge">lg</code>, and <code class="language-plaintext highlighter-rouge">xl</code>.</p>
<figure class="highlight"><pre><code class="language-html" data-lang="html"><span class="nt">&lt;div</span> <span class="na">class=</span><span class="s">"container-sm"</span><span class="nt">&gt;</span>100% wide until small breakpoint<span class="nt">&lt;/div&gt;</span>
<span class="nt">&lt;div</span> <span class="na">class=</span><span class="s">"container-md"</span><span class="nt">&gt;</span>100% wide until medium breakpoint<span class="nt">&lt;/div&gt;</span>
<span class="nt">&lt;div</span> <span class="na">class=</span><span class="s">"container-lg"</span><span class="nt">&gt;</span>100% wide until large breakpoint<span class="nt">&lt;/div&gt;</span>
<span class="nt">&lt;div</span> <span class="na">class=</span><span class="s">"container-xl"</span><span class="nt">&gt;</span>100% wide until extra large breakpoint<span class="nt">&lt;/div&gt;</span></code></pre></figure>
<h2 id="responsive-breakpoints">Responsive breakpoints</h2>
<p>Since Bootstrap is developed to be mobile first, we use a handful of <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Using_media_queries">media queries</a> to create sensible breakpoints for our layouts and interfaces. These breakpoints are mostly based on minimum viewport widths and allow us to scale up elements as the viewport changes.</p>
<p>Bootstrap primarily uses the following media query ranges—or breakpoints—in our source Sass files for our layout, grid system, and components.</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="c1">// Extra small devices (portrait phones, less than 576px)</span>
<span class="c1">// No media query for `xs` since this is the default in Bootstrap</span>
<span class="c1">// Small devices (landscape phones, 576px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">576px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Medium devices (tablets, 768px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">768px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Large devices (desktops, 992px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">992px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Extra large devices (large desktops, 1200px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">1200px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span></code></pre></figure>
<p>Since we write our source CSS in Sass, all our media queries are available via Sass mixins:</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="c1">// No media query necessary for xs breakpoint as it's effectively `@media (min-width: 0) { ... }`</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-up</span><span class="p">(</span><span class="n">sm</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-up</span><span class="p">(</span><span class="n">md</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-up</span><span class="p">(</span><span class="n">lg</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-up</span><span class="p">(</span><span class="n">xl</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Example: Hide starting at `min-width: 0`, and then show at the `sm` breakpoint</span>
<span class="nc">.custom-class</span> <span class="p">{</span>
<span class="nl">display</span><span class="p">:</span> <span class="nb">none</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-up</span><span class="p">(</span><span class="n">sm</span><span class="p">)</span> <span class="p">{</span>
<span class="nc">.custom-class</span> <span class="p">{</span>
<span class="nl">display</span><span class="p">:</span> <span class="nb">block</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span></code></pre></figure>
<p>We occasionally use media queries that go in the other direction (the given screen size <em>or smaller</em>):</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="c1">// Extra small devices (portrait phones, less than 576px)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">575</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Small devices (landscape phones, less than 768px)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">767</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Medium devices (tablets, less than 992px)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">991</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Large devices (desktops, less than 1200px)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">1199</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Extra large devices (large desktops)</span>
<span class="c1">// No media query since the extra-large breakpoint has no upper bound on its width</span></code></pre></figure>
<div class="bd-callout bd-callout-info">
<p>Note that since browsers do not currently support <a href="https://www.w3.org/TR/mediaqueries-4/#range-context">range context queries</a>, we work around the limitations of <a href="https://www.w3.org/TR/mediaqueries-4/#mq-min-max"><code class="language-plaintext highlighter-rouge">min-</code> and <code class="language-plaintext highlighter-rouge">max-</code> prefixes</a> and viewports with fractional widths (which can occur under certain conditions on high-dpi devices, for instance) by using values with higher precision for these comparisons.</p>
</div>
<p>Once again, these media queries are also available via Sass mixins:</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="k">@include</span> <span class="nd">media-breakpoint-down</span><span class="p">(</span><span class="n">xs</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-down</span><span class="p">(</span><span class="n">sm</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-down</span><span class="p">(</span><span class="n">md</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-down</span><span class="p">(</span><span class="n">lg</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// No media query necessary for xl breakpoint as it has no upper bound on its width</span>
<span class="c1">// Example: Style from medium breakpoint and down</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-down</span><span class="p">(</span><span class="n">md</span><span class="p">)</span> <span class="p">{</span>
<span class="nc">.custom-class</span> <span class="p">{</span>
<span class="nl">display</span><span class="p">:</span> <span class="nb">block</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span></code></pre></figure>
<p>There are also media queries and mixins for targeting a single segment of screen sizes using the minimum and maximum breakpoint widths.</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="c1">// Extra small devices (portrait phones, less than 576px)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">575</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Small devices (landscape phones, 576px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">576px</span><span class="p">)</span> <span class="nf">and</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">767</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Medium devices (tablets, 768px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">768px</span><span class="p">)</span> <span class="nf">and</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">991</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Large devices (desktops, 992px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">992px</span><span class="p">)</span> <span class="nf">and</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">1199</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="c1">// Extra large devices (large desktops, 1200px and up)</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">1200px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span></code></pre></figure>
<p>These media queries are also available via Sass mixins:</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="k">@include</span> <span class="nd">media-breakpoint-only</span><span class="p">(</span><span class="n">xs</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-only</span><span class="p">(</span><span class="n">sm</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-only</span><span class="p">(</span><span class="n">md</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-only</span><span class="p">(</span><span class="n">lg</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span>
<span class="k">@include</span> <span class="nd">media-breakpoint-only</span><span class="p">(</span><span class="n">xl</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span></code></pre></figure>
<p>Similarly, media queries may span multiple breakpoint widths:</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="c1">// Example</span>
<span class="c1">// Apply styles starting from medium devices and up to extra large devices</span>
<span class="k">@media</span> <span class="p">(</span><span class="n">min-width</span><span class="o">:</span> <span class="m">768px</span><span class="p">)</span> <span class="nf">and</span> <span class="p">(</span><span class="n">max-width</span><span class="o">:</span> <span class="m">1199</span><span class="mi">.98px</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span></code></pre></figure>
<p>The Sass mixin for targeting the same screen size range would be:</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="k">@include</span> <span class="nd">media-breakpoint-between</span><span class="p">(</span><span class="n">md</span><span class="o">,</span> <span class="n">xl</span><span class="p">)</span> <span class="p">{</span> <span class="nc">...</span> <span class="p">}</span></code></pre></figure>
<h2 id="z-index">Z-index</h2>
<p>Several Bootstrap components utilize <code class="language-plaintext highlighter-rouge">z-index</code>, the CSS property that helps control layout by providing a third axis to arrange content. We utilize a default z-index scale in Bootstrap thats been designed to properly layer navigation, tooltips and popovers, modals, and more.</p>
<p>These higher values start at an arbitrary number, high and specific enough to ideally avoid conflicts. We need a standard set of these across our layered components—tooltips, popovers, navbars, dropdowns, modals—so we can be reasonably consistent in the behaviors. Theres no reason we couldnt have used <code class="language-plaintext highlighter-rouge">100</code>+ or <code class="language-plaintext highlighter-rouge">500</code>+.</p>
<p>We dont encourage customization of these individual values; should you change one, you likely need to change them all.</p>
<figure class="highlight"><pre><code class="language-scss" data-lang="scss"><span class="nv">$zindex-dropdown</span><span class="p">:</span> <span class="m">1000</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span>
<span class="nv">$zindex-sticky</span><span class="p">:</span> <span class="m">1020</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span>
<span class="nv">$zindex-fixed</span><span class="p">:</span> <span class="m">1030</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span>
<span class="nv">$zindex-modal-backdrop</span><span class="p">:</span> <span class="m">1040</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span>
<span class="nv">$zindex-modal</span><span class="p">:</span> <span class="m">1050</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span>
<span class="nv">$zindex-popover</span><span class="p">:</span> <span class="m">1060</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span>
<span class="nv">$zindex-tooltip</span><span class="p">:</span> <span class="m">1070</span> <span class="o">!</span><span class="nb">default</span><span class="p">;</span></code></pre></figure>
<p>To handle overlapping borders within components (e.g., buttons and inputs in input groups), we use low single digit <code class="language-plaintext highlighter-rouge">z-index</code> values of <code class="language-plaintext highlighter-rouge">1</code>, <code class="language-plaintext highlighter-rouge">2</code>, and <code class="language-plaintext highlighter-rouge">3</code> for default, hover, and active states. On hover/focus/active, we bring a particular element to the forefront with a higher <code class="language-plaintext highlighter-rouge">z-index</code> value to show their border over the sibling elements.</p>
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