mirror of
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797 lines
39 KiB
HTML
797 lines
39 KiB
HTML
<!doctype html>
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<html lang="en">
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<head>
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<meta charset="utf-8">
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<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
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<meta name="description" content="Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon.">
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<meta name="author" content="Mark Otto, Jacob Thornton, and Bootstrap contributors">
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<meta name="generator" content="Jekyll v3.8.0">
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<title>Reboot · Bootstrap</title>
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<!-- Bootstrap core CSS -->
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<link href="/docs/4.1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
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<!-- Documentation extras -->
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<link href="https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.css" rel="stylesheet">
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<link href="/docs/4.1/assets//css/docs.min.css" rel="stylesheet">
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<!-- Favicons -->
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<link rel="apple-touch-icon" href="/docs/4.1/assets/img/favicons/apple-touch-icon.png" sizes="180x180">
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<link rel="icon" href="/docs/4.1/assets/img/favicons/favicon-32x32.png" sizes="32x32" type="image/png">
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<link rel="icon" href="/docs/4.1/assets/img/favicons/favicon-16x16.png" sizes="16x16" type="image/png">
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<link rel="manifest" href="/docs/4.1/assets/img/favicons/manifest.json">
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<link rel="mask-icon" href="/docs/4.1/assets/img/favicons/safari-pinned-tab.svg" color="#563d7c">
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<link rel="icon" href="/favicon.ico">
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<meta name="msapplication-config" content="/assets/img/favicons/browserconfig.xml">
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<meta name="theme-color" content="#563d7c">
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<!-- Twitter -->
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<meta name="twitter:card" content="summary">
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<meta name="twitter:site" content="@getbootstrap">
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<meta name="twitter:creator" content="@getbootstrap">
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<meta name="twitter:title" content="Reboot">
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<meta name="twitter:description" content="Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon.">
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<meta name="twitter:image" content="https://getbootstrap.com/assets/brand/bootstrap-social-logo.png">
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<!-- Facebook -->
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<meta property="og:url" content="https://getbootstrap.com/docs/4.1/content/reboot/">
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<meta property="og:title" content="Reboot">
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<meta property="og:description" content="Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon.">
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<meta property="og:type" content="website">
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<meta property="og:image" content="http://getbootstrap.com/assets/brand/bootstrap-social.png">
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<meta property="og:image:secure_url" content="https://getbootstrap.com/assets/brand/bootstrap-social.png">
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<meta property="og:image:type" content="image/png">
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<meta property="og:image:width" content="1200">
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<meta property="og:image:height" content="630">
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<script>
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(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
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(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
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m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
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})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
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ga('create', 'UA-146052-10', 'getbootstrap.com');
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ga('send', 'pageview');
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</script>
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</head>
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<body>
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<a id="skippy" class="sr-only sr-only-focusable" href="#content">
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<div class="container">
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<span class="skiplink-text">Skip to main content</span>
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</div>
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</a>
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<header class="navbar navbar-expand navbar-dark flex-column flex-md-row bd-navbar">
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<a class="navbar-brand mr-0 mr-md-2" href="/" aria-label="Bootstrap"><svg class="d-block" width="36" height="36" viewbox="0 0 612 612" xmlns="http://www.w3.org/2000/svg" focusable="false"><title>Bootstrap</title><path fill="currentColor" d="M510 8a94.3 94.3 0 0 1 94 94v408a94.3 94.3 0 0 1-94 94H102a94.3 94.3 0 0 1-94-94V102a94.3 94.3 0 0 1 94-94h408m0-8H102C45.9 0 0 45.9 0 102v408c0 56.1 45.9 102 102 102h408c56.1 0 102-45.9 102-102V102C612 45.9 566.1 0 510 0z"/><path fill="currentColor" d="M196.77 471.5V154.43h124.15c54.27 0 91 31.64 91 79.1 0 33-24.17 63.72-54.71 69.21v1.76c43.07 5.49 70.75 35.82 70.75 78 0 55.81-40 89-107.45 89zm39.55-180.4h63.28c46.8 0 72.29-18.68 72.29-53 0-31.42-21.53-48.78-60-48.78h-75.57zm78.22 145.46c47.68 0 72.73-19.34 72.73-56s-25.93-55.37-76.46-55.37h-74.49v111.4z"/></svg>
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</a>
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<div class="navbar-nav-scroll">
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<ul class="navbar-nav bd-navbar-nav flex-row">
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<li class="nav-item">
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<a class="nav-link " href="/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Bootstrap');">Home</a>
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</li>
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<li class="nav-item">
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<a class="nav-link active" href="/docs/4.1/getting-started/introduction/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Docs');">Documentation</a>
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</li>
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<li class="nav-item">
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<a class="nav-link " href="/docs/4.1/examples/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Examples');">Examples</a>
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</li>
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<li class="nav-item">
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<a class="nav-link" href="https://themes.getbootstrap.com" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Themes');" target="_blank" rel="noopener">Themes</a>
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</li>
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<li class="nav-item">
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<a class="nav-link" href="https://jobs.getbootstrap.com" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Jobs');" target="_blank" rel="noopener">Jobs</a>
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</li>
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<li class="nav-item">
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<a class="nav-link" href="https://expo.getbootstrap.com" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Expo');" target="_blank" rel="noopener">Expo</a>
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</li>
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<li class="nav-item">
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<a class="nav-link" href="https://blog.getbootstrap.com" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Blog');" target="_blank" rel="noopener">Blog</a>
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</li>
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</ul>
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</div>
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<ul class="navbar-nav flex-row ml-md-auto d-none d-md-flex">
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<li class="nav-item dropdown">
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<a class="nav-item nav-link dropdown-toggle mr-md-2" href="#" id="bd-versions" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
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v4.1
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</a>
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<div class="dropdown-menu dropdown-menu-right" aria-labelledby="bd-versions">
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<a class="dropdown-item active" href="/docs/4.1/">Latest (4.1.x)</a>
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<a class="dropdown-item" href="https://getbootstrap.com/docs/4.0/">v4.0.0</a>
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<div class="dropdown-divider"></div>
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<a class="dropdown-item" href="https://v4-alpha.getbootstrap.com/">v4 Alpha 6</a>
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<a class="dropdown-item" href="https://getbootstrap.com/docs/3.3/">v3.3.7</a>
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<a class="dropdown-item" href="https://getbootstrap.com/2.3.2/">v2.3.2</a>
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</div>
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</li>
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<li class="nav-item">
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<a class="nav-link p-2" href="https://github.com/twbs/bootstrap" target="_blank" rel="noopener" aria-label="GitHub"><svg class="navbar-nav-svg" xmlns="http://www.w3.org/2000/svg" viewbox="0 0 512 499.36" focusable="false"><title>GitHub</title><path d="M256 0C114.64 0 0 114.61 0 256c0 113.09 73.34 209 175.08 242.9 12.8 2.35 17.47-5.56 17.47-12.34 0-6.08-.22-22.18-.35-43.54-71.2 15.49-86.2-34.34-86.2-34.34-11.64-29.57-28.42-37.45-28.42-37.45-23.27-15.84 1.73-15.55 1.73-15.55 25.69 1.81 39.21 26.38 39.21 26.38 22.84 39.12 59.92 27.82 74.5 21.27 2.33-16.54 8.94-27.82 16.25-34.22-56.84-6.43-116.6-28.43-116.6-126.49 0-27.95 10-50.8 26.35-68.69-2.63-6.48-11.42-32.5 2.51-67.75 0 0 21.49-6.88 70.4 26.24a242.65 242.65 0 0 1 128.18 0c48.87-33.13 70.33-26.24 70.33-26.24 14 35.25 5.18 61.27 2.55 67.75 16.41 17.9 26.31 40.75 26.31 68.69 0 98.35-59.85 120-116.88 126.32 9.19 7.9 17.38 23.53 17.38 47.41 0 34.22-.31 61.83-.31 70.23 0 6.85 4.61 14.81 17.6 12.31C438.72 464.97 512 369.08 512 256.02 512 114.62 397.37 0 256 0z" fill="currentColor" fill-rule="evenodd"/></svg>
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</a>
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</li>
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<li class="nav-item">
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<a class="nav-link p-2" href="https://twitter.com/getbootstrap" target="_blank" rel="noopener" aria-label="Twitter"><svg class="navbar-nav-svg" xmlns="http://www.w3.org/2000/svg" viewbox="0 0 512 416.32" focusable="false"><title>Twitter</title><path d="M160.83 416.32c193.2 0 298.92-160.22 298.92-298.92 0-4.51 0-9-.2-13.52A214 214 0 0 0 512 49.38a212.93 212.93 0 0 1-60.44 16.6 105.7 105.7 0 0 0 46.3-58.19 209 209 0 0 1-66.79 25.37 105.09 105.09 0 0 0-181.73 71.91 116.12 116.12 0 0 0 2.66 24c-87.28-4.3-164.73-46.3-216.56-109.82A105.48 105.48 0 0 0 68 159.6a106.27 106.27 0 0 1-47.53-13.11v1.43a105.28 105.28 0 0 0 84.21 103.06 105.67 105.67 0 0 1-47.33 1.84 105.06 105.06 0 0 0 98.14 72.94A210.72 210.72 0 0 1 25 370.84a202.17 202.17 0 0 1-25-1.43 298.85 298.85 0 0 0 160.83 46.92" fill="currentColor"/></svg>
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</a>
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</li>
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<li class="nav-item">
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<a class="nav-link p-2" href="https://bootstrap-slack.herokuapp.com" target="_blank" rel="noopener" aria-label="Slack"><svg class="navbar-nav-svg" xmlns="http://www.w3.org/2000/svg" viewbox="0 0 512 512" focusable="false"><title>Slack</title><path fill="currentColor" d="M210.787 234.832l68.31-22.883 22.1 65.977-68.309 22.882z"/><path d="M490.54 185.6C437.7 9.59 361.6-31.34 185.6 21.46S-31.3 150.4 21.46 326.4 150.4 543.3 326.4 490.54 543.34 361.6 490.54 185.6zM401.7 299.8l-33.15 11.05 11.46 34.38c4.5 13.92-2.87 29.06-16.78 33.56-2.87.82-6.14 1.64-9 1.23a27.32 27.32 0 0 1-24.56-18l-11.46-34.38-68.36 22.92 11.46 34.38c4.5 13.92-2.87 29.06-16.78 33.56-2.87.82-6.14 1.64-9 1.23a27.32 27.32 0 0 1-24.56-18l-11.46-34.43-33.15 11.05c-2.87.82-6.14 1.64-9 1.23a27.32 27.32 0 0 1-24.56-18c-4.5-13.92 2.87-29.06 16.78-33.56l33.12-11.03-22.1-65.9-33.15 11.05c-2.87.82-6.14 1.64-9 1.23a27.32 27.32 0 0 1-24.56-18c-4.48-13.93 2.89-29.07 16.81-33.58l33.15-11.05-11.46-34.38c-4.5-13.92 2.87-29.06 16.78-33.56s29.06 2.87 33.56 16.78l11.46 34.38 68.36-22.92-11.46-34.38c-4.5-13.92 2.87-29.06 16.78-33.56s29.06 2.87 33.56 16.78l11.47 34.42 33.15-11.05c13.92-4.5 29.06 2.87 33.56 16.78s-2.87 29.06-16.78 33.56L329.7 194.6l22.1 65.9 33.15-11.05c13.92-4.5 29.06 2.87 33.56 16.78s-2.88 29.07-16.81 33.57z" fill="currentColor"/></svg>
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</a>
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</li>
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</ul>
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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="https://github.com/twbs/bootstrap/archive/v4.1.1.zip">Download</a>
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</header>
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<div class="container-fluid">
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<div class="row flex-xl-nowrap">
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<div class="col-12 col-md-3 col-xl-2 bd-sidebar">
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<form class="bd-search d-flex align-items-center">
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<input type="search" class="form-control" id="search-input" placeholder="Search..." aria-label="Search for..." autocomplete="off" data-siteurl="https://getbootstrap.com" data-docs-version="4.1">
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<button class="btn btn-link 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" viewbox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"/></svg>
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</button>
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</form>
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<nav class="collapse bd-links" id="bd-docs-nav"><div class="bd-toc-item">
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<a class="bd-toc-link" href="/docs/4.1/getting-started/introduction/">
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Getting started
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</a>
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<ul class="nav bd-sidenav"><li>
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<a href="/docs/4.1/getting-started/introduction/">
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Introduction
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</a></li><li>
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<a href="/docs/4.1/getting-started/download/">
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Download
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</a></li><li>
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<a href="/docs/4.1/getting-started/contents/">
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Contents
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</a></li><li>
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<a href="/docs/4.1/getting-started/browsers-devices/">
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Browsers & devices
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</a></li><li>
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<a href="/docs/4.1/getting-started/javascript/">
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JavaScript
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</a></li><li>
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<a href="/docs/4.1/getting-started/theming/">
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Theming
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</a></li><li>
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<a href="/docs/4.1/getting-started/build-tools/">
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Build tools
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</a></li><li>
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<a href="/docs/4.1/getting-started/webpack/">
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Webpack
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</a></li><li>
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<a href="/docs/4.1/getting-started/accessibility/">
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Accessibility
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</a></li></ul>
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</div><div class="bd-toc-item">
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<a class="bd-toc-link" href="/docs/4.1/layout/overview/">
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Layout
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</a>
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<ul class="nav bd-sidenav"><li>
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<a href="/docs/4.1/layout/overview/">
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Overview
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</a></li><li>
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<a href="/docs/4.1/layout/grid/">
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Grid
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</a></li><li>
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<a href="/docs/4.1/layout/media-object/">
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Media object
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</a></li><li>
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<a href="/docs/4.1/layout/utilities-for-layout/">
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Utilities for layout
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</a></li></ul>
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</div><div class="bd-toc-item active">
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<a class="bd-toc-link" href="/docs/4.1/content/reboot/">
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Content
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</a>
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<ul class="nav bd-sidenav"><li class="active bd-sidenav-active">
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<a href="/docs/4.1/content/reboot/">
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Reboot
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</a></li><li>
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<a href="/docs/4.1/content/typography/">
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Typography
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</a></li><li>
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<a href="/docs/4.1/content/code/">
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Code
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</a></li><li>
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<a href="/docs/4.1/content/images/">
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Images
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</a></li><li>
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<a href="/docs/4.1/content/tables/">
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Tables
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</a></li><li>
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<a href="/docs/4.1/content/figures/">
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Figures
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</a></li></ul>
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</div><div class="bd-toc-item">
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<a class="bd-toc-link" href="/docs/4.1/components/alerts/">
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Components
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</a>
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<ul class="nav bd-sidenav"><li>
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<a href="/docs/4.1/components/alerts/">
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Alerts
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</a></li><li>
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<a href="/docs/4.1/components/badge/">
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Badge
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</a></li><li>
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<a href="/docs/4.1/components/breadcrumb/">
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Breadcrumb
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</a></li><li>
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<a href="/docs/4.1/components/buttons/">
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Buttons
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</a></li><li>
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<a href="/docs/4.1/components/button-group/">
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Button group
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</a></li><li>
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<a href="/docs/4.1/components/card/">
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Card
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</a></li><li>
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<a href="/docs/4.1/components/carousel/">
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Carousel
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</a></li><li>
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<a href="/docs/4.1/components/collapse/">
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Collapse
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</a></li><li>
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<a href="/docs/4.1/components/dropdowns/">
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Dropdowns
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</a></li><li>
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<a href="/docs/4.1/components/forms/">
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Forms
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</a></li><li>
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<a href="/docs/4.1/components/input-group/">
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Input group
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</a></li><li>
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<a href="/docs/4.1/components/jumbotron/">
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Jumbotron
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</a></li><li>
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<a href="/docs/4.1/components/list-group/">
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List group
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</a></li><li>
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<a href="/docs/4.1/components/modal/">
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Modal
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</a></li><li>
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<a href="/docs/4.1/components/navs/">
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Navs
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</a></li><li>
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<a href="/docs/4.1/components/navbar/">
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Navbar
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</a></li><li>
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<a href="/docs/4.1/components/pagination/">
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Pagination
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</a></li><li>
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<a href="/docs/4.1/components/popovers/">
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Popovers
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</a></li><li>
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<a href="/docs/4.1/components/progress/">
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Progress
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</a></li><li>
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<a href="/docs/4.1/components/scrollspy/">
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Scrollspy
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</a></li><li>
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<a href="/docs/4.1/components/tooltips/">
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Tooltips
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</a></li></ul>
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</div><div class="bd-toc-item">
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<a class="bd-toc-link" href="/docs/4.1/utilities/borders/">
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Utilities
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</a>
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||
<ul class="nav bd-sidenav"><li>
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<a href="/docs/4.1/utilities/borders/">
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Borders
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</a></li><li>
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<a href="/docs/4.1/utilities/clearfix/">
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Clearfix
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</a></li><li>
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<a href="/docs/4.1/utilities/close-icon/">
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Close icon
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</a></li><li>
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<a href="/docs/4.1/utilities/colors/">
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Colors
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</a></li><li>
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<a href="/docs/4.1/utilities/display/">
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Display
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</a></li><li>
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<a href="/docs/4.1/utilities/embed/">
|
||
Embed
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/flex/">
|
||
Flex
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/float/">
|
||
Float
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/image-replacement/">
|
||
Image replacement
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/position/">
|
||
Position
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/screenreaders/">
|
||
Screenreaders
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/shadows/">
|
||
Shadows
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/sizing/">
|
||
Sizing
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/spacing/">
|
||
Spacing
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/text/">
|
||
Text
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/vertical-align/">
|
||
Vertical align
|
||
</a></li><li>
|
||
<a href="/docs/4.1/utilities/visibility/">
|
||
Visibility
|
||
</a></li></ul>
|
||
</div><div class="bd-toc-item">
|
||
<a class="bd-toc-link" href="/docs/4.1/extend/approach/">
|
||
Extend
|
||
</a>
|
||
|
||
<ul class="nav bd-sidenav"><li>
|
||
<a href="/docs/4.1/extend/approach/">
|
||
Approach
|
||
</a></li><li>
|
||
<a href="/docs/4.1/extend/icons/">
|
||
Icons
|
||
</a></li></ul>
|
||
</div><div class="bd-toc-item">
|
||
<a class="bd-toc-link" href="/docs/4.1/migration/">
|
||
Migration
|
||
</a>
|
||
|
||
<ul class="nav bd-sidenav"></ul>
|
||
</div><div class="bd-toc-item">
|
||
<a class="bd-toc-link" href="/docs/4.1/about/overview/">
|
||
About
|
||
</a>
|
||
|
||
<ul class="nav bd-sidenav"><li>
|
||
<a href="/docs/4.1/about/overview/">
|
||
Overview
|
||
</a></li><li>
|
||
<a href="/docs/4.1/about/brand/">
|
||
Brand
|
||
</a></li><li>
|
||
<a href="/docs/4.1/about/license/">
|
||
License
|
||
</a></li><li>
|
||
<a href="/docs/4.1/about/translations/">
|
||
Translations
|
||
</a></li></ul>
|
||
</div></nav>
|
||
|
||
</div>
|
||
|
||
|
||
<div class="d-none d-xl-block col-xl-2 bd-toc">
|
||
<ul class="section-nav">
|
||
<li class="toc-entry toc-h2"><a href="#approach">Approach</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#page-defaults">Page defaults</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#native-font-stack">Native font stack</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#headings-and-paragraphs">Headings and paragraphs</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#lists">Lists</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#preformatted-text">Preformatted text</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#tables">Tables</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#forms">Forms</a></li>
|
||
<li class="toc-entry toc-h2"><a href="#misc-elements">Misc elements</a>
|
||
<ul>
|
||
<li class="toc-entry toc-h3"><a href="#address">Address</a></li>
|
||
<li class="toc-entry toc-h3"><a href="#blockquote">Blockquote</a></li>
|
||
<li class="toc-entry toc-h3"><a href="#inline-elements">Inline elements</a></li>
|
||
<li class="toc-entry toc-h3"><a href="#summary">Summary</a></li>
|
||
</ul>
|
||
</li>
|
||
<li class="toc-entry toc-h2"><a href="#html5-hidden-attribute">HTML5 [hidden] attribute</a></li>
|
||
</ul>
|
||
</div>
|
||
|
||
|
||
<main class="col-12 col-md-9 col-xl-8 py-md-3 pl-md-5 bd-content" role="main">
|
||
<h1 class="bd-title" id="content">Reboot</h1>
|
||
<p class="bd-lead">Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon.</p>
|
||
<script async src="https://cdn.carbonads.com/carbon.js?zoneid=1673&serve=C6AILKT&placement=getbootstrapcom" id="_carbonads_js"></script>
|
||
|
||
<h2 id="approach">Approach</h2>
|
||
|
||
<p>Reboot builds upon Normalize, providing many HTML elements with somewhat opinionated styles using only element selectors. Additional styling is done only with classes. For example, we reboot some <code class="highlighter-rouge"><table></code> styles for a simpler baseline and later provide <code class="highlighter-rouge">.table</code>, <code class="highlighter-rouge">.table-bordered</code>, and more.</p>
|
||
|
||
<p>Here are our guidelines and reasons for choosing what to override in Reboot:</p>
|
||
|
||
<ul>
|
||
<li>Update some browser default values to use <code class="highlighter-rouge">rem</code>s instead of <code class="highlighter-rouge">em</code>s for scalable component spacing.</li>
|
||
<li>Avoid <code class="highlighter-rouge">margin-top</code>. Vertical margins can collapse, yielding unexpected results. More importantly though, a single direction of <code class="highlighter-rouge">margin</code> is a simpler mental model.</li>
|
||
<li>For easier scaling across device sizes, block elements should use <code class="highlighter-rouge">rem</code>s for <code class="highlighter-rouge">margin</code>s.</li>
|
||
<li>Keep declarations of <code class="highlighter-rouge">font</code>-related properties to a minimum, using <code class="highlighter-rouge">inherit</code> whenever possible.</li>
|
||
</ul>
|
||
|
||
<h2 id="page-defaults">Page defaults</h2>
|
||
|
||
<p>The <code class="highlighter-rouge"><span class="nt"><html></span></code> and <code class="highlighter-rouge"><body></code> elements are updated to provide better page-wide defaults. More specifically:</p>
|
||
|
||
<ul>
|
||
<li>The <code class="highlighter-rouge">box-sizing</code> is globally set on every element—including <code class="highlighter-rouge">*::before</code> and <code class="highlighter-rouge">*::after</code>, to <code class="highlighter-rouge">border-box</code>. This ensures that the declared width of element is never exceeded due to padding or border.
|
||
<ul>
|
||
<li>No base <code class="highlighter-rouge">font-size</code> is declared on the <code class="highlighter-rouge"><span class="nt"><html></span></code>, but <code class="highlighter-rouge">16px</code> is assumed (the browser default). <code class="highlighter-rouge">font-size: 1rem</code> is applied on the <code class="highlighter-rouge"><body></code> for easy responsive type-scaling via media queries while respecting user preferences and ensuring a more accessible approach.</li>
|
||
</ul>
|
||
</li>
|
||
<li>The <code class="highlighter-rouge"><body></code> also sets a global <code class="highlighter-rouge">font-family</code>, <code class="highlighter-rouge">line-height</code>, and <code class="highlighter-rouge">text-align</code>. This is inherited later by some form elements to prevent font inconsistencies.</li>
|
||
<li>For safety, the <code class="highlighter-rouge"><body></code> has a declared <code class="highlighter-rouge">background-color</code>, defaulting to <code class="highlighter-rouge">#fff</code>.</li>
|
||
</ul>
|
||
|
||
<h2 id="native-font-stack">Native font stack</h2>
|
||
|
||
<p>The default web fonts (Helvetica Neue, Helvetica, and Arial) have been dropped in Bootstrap 4 and replaced with a “native font stack” for optimum text rendering on every device and OS. Read more about <a href="https://www.smashingmagazine.com/2015/11/using-system-ui-fonts-practical-guide/">native font stacks in this <em>Smashing Magazine</em> article</a>.</p>
|
||
|
||
<figure class="highlight"><pre><code class="language-sass" data-lang="sass"><span class="nv">$font-family-sans-serif</span><span class="p">:</span>
|
||
<span class="c1">// Safari for OS X and iOS (San Francisco)</span>
|
||
<span class="nt">-apple-system</span><span class="o">,</span>
|
||
<span class="c1">// Chrome < 56 for OS X (San Francisco)</span>
|
||
<span class="nt">BlinkMacSystemFont</span><span class="o">,</span>
|
||
<span class="c1">// Windows</span>
|
||
<span class="s2">"Segoe UI"</span><span class="o">,</span>
|
||
<span class="c1">// Android</span>
|
||
<span class="s2">"Roboto"</span><span class="o">,</span>
|
||
<span class="c1">// Basic web fallback</span>
|
||
<span class="s2">"Helvetica Neue"</span><span class="o">,</span> <span class="nt">Arial</span><span class="o">,</span> <span class="nt">sans-serif</span><span class="o">,</span>
|
||
<span class="c1">// Emoji fonts</span>
|
||
<span class="s2">"Apple Color Emoji"</span><span class="o">,</span> <span class="s2">"Segoe UI Emoji"</span><span class="o">,</span> <span class="s2">"Segoe UI Symbol"</span> <span class="o">!</span><span class="nt">default</span><span class="o">;</span></code></pre></figure>
|
||
|
||
<p>This <code class="highlighter-rouge">font-family</code> is applied to the <code class="highlighter-rouge"><body></code> and automatically inherited globally throughout Bootstrap. To switch the global <code class="highlighter-rouge">font-family</code>, update <code class="highlighter-rouge">$font-family-base</code> and recompile Bootstrap.</p>
|
||
|
||
<h2 id="headings-and-paragraphs">Headings and paragraphs</h2>
|
||
|
||
<p>All heading elements—e.g., <code class="highlighter-rouge"><h1></code>—and <code class="highlighter-rouge"><p></code> are reset to have their <code class="highlighter-rouge">margin-top</code> removed. Headings have <code class="highlighter-rouge">margin-bottom: .5rem</code> added and paragraphs <code class="highlighter-rouge">margin-bottom: 1rem</code> for easy spacing.</p>
|
||
|
||
<table>
|
||
<thead>
|
||
<tr>
|
||
<th>Heading</th>
|
||
<th>Example</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr>
|
||
<td>
|
||
<p><code class="highlighter-rouge"><h1></h1></code></p>
|
||
|
||
</td>
|
||
<td><span class="h1">h1. Bootstrap heading</span></td>
|
||
</tr>
|
||
<tr>
|
||
<td>
|
||
<p><code class="highlighter-rouge"><h2></h2></code></p>
|
||
|
||
</td>
|
||
<td><span class="h2">h2. Bootstrap heading</span></td>
|
||
</tr>
|
||
<tr>
|
||
<td>
|
||
<p><code class="highlighter-rouge"><h3></h3></code></p>
|
||
|
||
</td>
|
||
<td><span class="h3">h3. Bootstrap heading</span></td>
|
||
</tr>
|
||
<tr>
|
||
<td>
|
||
<p><code class="highlighter-rouge"><h4></h4></code></p>
|
||
|
||
</td>
|
||
<td><span class="h4">h4. Bootstrap heading</span></td>
|
||
</tr>
|
||
<tr>
|
||
<td>
|
||
<p><code class="highlighter-rouge"><h5></h5></code></p>
|
||
|
||
</td>
|
||
<td><span class="h5">h5. Bootstrap heading</span></td>
|
||
</tr>
|
||
<tr>
|
||
<td>
|
||
<p><code class="highlighter-rouge"><h6></h6></code></p>
|
||
|
||
</td>
|
||
<td><span class="h6">h6. Bootstrap heading</span></td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
|
||
<h2 id="lists">Lists</h2>
|
||
|
||
<p>All lists—<code class="highlighter-rouge"><ul></code>, <code class="highlighter-rouge"><ol></code>, and <code class="highlighter-rouge"><dl></code>—have their <code class="highlighter-rouge">margin-top</code> removed and a <code class="highlighter-rouge">margin-bottom: 1rem</code>. Nested lists have no <code class="highlighter-rouge">margin-bottom</code>.</p>
|
||
|
||
<div class="bd-example">
|
||
|
||
|
||
<ul>
|
||
<li>Lorem ipsum dolor sit amet</li>
|
||
<li>Consectetur adipiscing elit</li>
|
||
<li>Integer molestie lorem at massa</li>
|
||
<li>Facilisis in pretium nisl aliquet</li>
|
||
<li>Nulla volutpat aliquam velit
|
||
<ul>
|
||
<li>Phasellus iaculis neque</li>
|
||
<li>Purus sodales ultricies</li>
|
||
<li>Vestibulum laoreet porttitor sem</li>
|
||
<li>Ac tristique libero volutpat at</li>
|
||
</ul>
|
||
</li>
|
||
<li>Faucibus porta lacus fringilla vel</li>
|
||
<li>Aenean sit amet erat nunc</li>
|
||
<li>Eget porttitor lorem</li>
|
||
</ul>
|
||
|
||
<ol>
|
||
<li>Lorem ipsum dolor sit amet</li>
|
||
<li>Consectetur adipiscing elit</li>
|
||
<li>Integer molestie lorem at massa</li>
|
||
<li>Facilisis in pretium nisl aliquet</li>
|
||
<li>Nulla volutpat aliquam velit</li>
|
||
<li>Faucibus porta lacus fringilla vel</li>
|
||
<li>Aenean sit amet erat nunc</li>
|
||
<li>Eget porttitor lorem</li>
|
||
</ol>
|
||
|
||
</div>
|
||
|
||
<p>For simpler styling, clear hierarchy, and better spacing, description lists have updated <code class="highlighter-rouge">margin</code>s. <code class="highlighter-rouge"><dd></code>s reset <code class="highlighter-rouge">margin-left</code> to <code class="highlighter-rouge">0</code> and add <code class="highlighter-rouge">margin-bottom: .5rem</code>. <code class="highlighter-rouge"><dt></code>s are <strong>bolded</strong>.</p>
|
||
|
||
<div class="bd-example">
|
||
<dl>
|
||
<dt>Description lists</dt>
|
||
<dd>A description list is perfect for defining terms.</dd>
|
||
<dt>Euismod</dt>
|
||
<dd>Vestibulum id ligula porta felis euismod semper eget lacinia odio sem.</dd>
|
||
<dd>Donec id elit non mi porta gravida at eget metus.</dd>
|
||
<dt>Malesuada porta</dt>
|
||
<dd>Etiam porta sem malesuada magna mollis euismod.</dd>
|
||
</dl>
|
||
</div>
|
||
|
||
<h2 id="preformatted-text">Preformatted text</h2>
|
||
|
||
<p>The <code class="highlighter-rouge"><pre></code> element is reset to remove its <code class="highlighter-rouge">margin-top</code> and use <code class="highlighter-rouge">rem</code> units for its <code class="highlighter-rouge">margin-bottom</code>.</p>
|
||
|
||
<div class="bd-example">
|
||
<pre>
|
||
.example-element {
|
||
margin-bottom: 1rem;
|
||
}
|
||
</pre>
|
||
</div>
|
||
|
||
<h2 id="tables">Tables</h2>
|
||
|
||
<p>Tables are slightly adjusted to style <code class="highlighter-rouge"><caption></code>s, collapse borders, and ensure consistent <code class="highlighter-rouge">text-align</code> throughout. Additional changes for borders, padding, and more come with <a href="/docs/4.1/content/tables/">the <code class="highlighter-rouge">.table</code> class</a>.</p>
|
||
|
||
<div class="bd-example">
|
||
<table>
|
||
<caption>
|
||
This is an example table, and this is its caption to describe the contents.
|
||
</caption>
|
||
<thead>
|
||
<tr>
|
||
<th>Table heading</th>
|
||
<th>Table heading</th>
|
||
<th>Table heading</th>
|
||
<th>Table heading</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
</tr>
|
||
<tr>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
</tr>
|
||
<tr>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
<td>Table cell</td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
</div>
|
||
|
||
<h2 id="forms">Forms</h2>
|
||
|
||
<p>Various form elements have been rebooted for simpler base styles. Here are some of the most notable changes:</p>
|
||
|
||
<ul>
|
||
<li><code class="highlighter-rouge"><fieldset></code>s have no borders, padding, or margin so they can be easily used as wrappers for individual inputs or groups of inputs.</li>
|
||
<li><code class="highlighter-rouge"><legend></code>s, like fieldsets, have also been restyled to be displayed as a heading of sorts.</li>
|
||
<li><code class="highlighter-rouge"><label></code>s are set to <code class="highlighter-rouge">display: inline-block</code> to allow <code class="highlighter-rouge">margin</code> to be applied.</li>
|
||
<li><code class="highlighter-rouge"><input></code>s, <code class="highlighter-rouge"><select></code>s, <code class="highlighter-rouge"><textarea></code>s, and <code class="highlighter-rouge"><button></code>s are mostly addressed by Normalize, but Reboot removes their <code class="highlighter-rouge">margin</code> and sets <code class="highlighter-rouge">line-height: inherit</code>, too.</li>
|
||
<li><code class="highlighter-rouge"><textarea></code>s are modified to only be resizable vertically as horizontal resizing often “breaks” page layout.</li>
|
||
</ul>
|
||
|
||
<p>These changes, and more, are demonstrated below.</p>
|
||
|
||
<form class="bd-example">
|
||
<fieldset>
|
||
<legend>Example legend</legend>
|
||
|
||
<p>
|
||
<label for="input">Example input</label>
|
||
<input type="text" id="input" placeholder="Example input" />
|
||
</p>
|
||
|
||
<p>
|
||
<label for="select">Example select</label>
|
||
<select id="select">
|
||
<option value="">Choose...</option>
|
||
<optgroup label="Option group 1">
|
||
<option value="">Option 1</option>
|
||
<option value="">Option 2</option>
|
||
<option value="">Option 3</option>
|
||
</optgroup>
|
||
<optgroup label="Option group 2">
|
||
<option value="">Option 4</option>
|
||
<option value="">Option 5</option>
|
||
<option value="">Option 6</option>
|
||
</optgroup>
|
||
</select>
|
||
</p>
|
||
|
||
<p>
|
||
<label>
|
||
<input type="checkbox" value="" />
|
||
Check this checkbox
|
||
</label>
|
||
</p>
|
||
|
||
<p>
|
||
<label>
|
||
<input type="radio" name="optionsRadios" id="optionsRadios1" value="option1" checked="" />
|
||
Option one is this and that
|
||
</label>
|
||
<label>
|
||
<input type="radio" name="optionsRadios" id="optionsRadios2" value="option2" />
|
||
Option two is something else that's also super long to demonstrate the wrapping of these fancy form controls.
|
||
</label>
|
||
<label>
|
||
<input type="radio" name="optionsRadios" id="optionsRadios3" value="option3" disabled="" />
|
||
Option three is disabled
|
||
</label>
|
||
</p>
|
||
|
||
<p>
|
||
<label for="textarea">Example textarea</label>
|
||
<textarea id="textarea" rows="3"></textarea>
|
||
</p>
|
||
|
||
<p>
|
||
<label for="date">Example date</label>
|
||
<input type="date" id="date" />
|
||
</p>
|
||
|
||
<p>
|
||
<label for="time">Example time</label>
|
||
<input type="time" id="time" />
|
||
</p>
|
||
|
||
<p>
|
||
<label for="output">Example output</label>
|
||
<output name="result" id="output">100</output>
|
||
</p>
|
||
|
||
<p>
|
||
<button type="submit">Button submit</button>
|
||
<input type="submit" value="Input submit button" />
|
||
<input type="button" value="Input button" />
|
||
</p>
|
||
|
||
<p>
|
||
<button type="submit" disabled="">Button submit</button>
|
||
<input type="submit" value="Input submit button" disabled="" />
|
||
<input type="button" value="Input button" disabled="" />
|
||
</p>
|
||
</fieldset>
|
||
</form>
|
||
|
||
<h2 id="misc-elements">Misc elements</h2>
|
||
|
||
<h3 id="address">Address</h3>
|
||
|
||
<p>The <code class="highlighter-rouge"><address></code> element is updated to reset the browser default <code class="highlighter-rouge">font-style</code> from <code class="highlighter-rouge">italic</code> to <code class="highlighter-rouge">normal</code>. <code class="highlighter-rouge">line-height</code> is also now inherited, and <code class="highlighter-rouge">margin-bottom: 1rem</code> has been added. <code class="highlighter-rouge"><address></code>s are for presenting contact information for the nearest ancestor (or an entire body of work). Preserve formatting by ending lines with <code class="highlighter-rouge"><br></code>.</p>
|
||
|
||
<div class="bd-example">
|
||
<address>
|
||
<strong>Twitter, Inc.</strong><br />
|
||
1355 Market St, Suite 900<br />
|
||
San Francisco, CA 94103<br />
|
||
<abbr title="Phone">P:</abbr> (123) 456-7890
|
||
</address>
|
||
|
||
<address>
|
||
<strong>Full Name</strong><br />
|
||
<a href="mailto:#">first.last@example.com</a>
|
||
</address>
|
||
</div>
|
||
|
||
<h3 id="blockquote">Blockquote</h3>
|
||
|
||
<p>The default <code class="highlighter-rouge">margin</code> on blockquotes is <code class="highlighter-rouge">1em 40px</code>, so we reset that to <code class="highlighter-rouge">0 0 1rem</code> for something more consistent with other elements.</p>
|
||
|
||
<div class="bd-example">
|
||
<blockquote class="blockquote">
|
||
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
|
||
<footer>Someone famous in <cite title="Source Title">Source Title</cite></footer>
|
||
</blockquote>
|
||
</div>
|
||
|
||
<h3 id="inline-elements">Inline elements</h3>
|
||
|
||
<p>The <code class="highlighter-rouge"><abbr></code> element receives basic styling to make it stand out amongst paragraph text.</p>
|
||
|
||
<div class="bd-example">
|
||
Nulla <abbr title="attribute">attr</abbr> vitae elit libero, a pharetra augue.
|
||
</div>
|
||
|
||
<h3 id="summary">Summary</h3>
|
||
|
||
<p>The default <code class="highlighter-rouge">cursor</code> on summary is <code class="highlighter-rouge">text</code>, so we reset that to <code class="highlighter-rouge">pointer</code> to convey that the element can be interacted with by clicking on it.</p>
|
||
|
||
<div class="bd-example">
|
||
<details>
|
||
<summary>Some details</summary>
|
||
<p>More info about the details.</p>
|
||
</details>
|
||
|
||
<details open="">
|
||
<summary>Even more details</summary>
|
||
<p>Here are even more details about the details.</p>
|
||
</details>
|
||
</div>
|
||
|
||
<h2 id="html5-hidden-attribute">HTML5 <code class="highlighter-rouge">[hidden]</code> attribute</h2>
|
||
|
||
<p>HTML5 adds <a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/hidden">a new global attribute named <code class="highlighter-rouge">[hidden]</code></a>, which is styled as <code class="highlighter-rouge">display: none</code> by default. Borrowing an idea from <a href="https://purecss.io/">PureCSS</a>, we improve upon this default by making <code class="highlighter-rouge">[hidden] { display: none !important; }</code> to help prevent its <code class="highlighter-rouge">display</code> from getting accidentally overridden. While <code class="highlighter-rouge">[hidden]</code> isn’t natively supported by IE10, the explicit declaration in our CSS gets around that problem.</p>
|
||
|
||
<figure class="highlight"><pre><code class="language-html" data-lang="html"><span class="nt"><input</span> <span class="na">type=</span><span class="s">"text"</span> <span class="na">hidden</span><span class="nt">></span></code></pre></figure>
|
||
|
||
<div class="bd-callout bd-callout-warning">
|
||
<h5 id="jquery-incompatibility">jQuery incompatibility</h5>
|
||
|
||
<p><code class="highlighter-rouge">[hidden]</code> is not compatible with jQuery’s <code class="highlighter-rouge">$(...).hide()</code> and <code class="highlighter-rouge">$(...).show()</code> methods. Therefore, we don’t currently especially endorse <code class="highlighter-rouge">[hidden]</code> over other techniques for managing the <code class="highlighter-rouge">display</code> of elements.</p>
|
||
</div>
|
||
|
||
<p>To merely toggle the visibility of an element, meaning its <code class="highlighter-rouge">display</code> is not modified and the element can still affect the flow of the document, use <a href="/docs/4.1/utilities/visibility/">the <code class="highlighter-rouge">.invisible</code> class</a> instead.</p>
|
||
|
||
</main>
|
||
</div>
|
||
</div>
|
||
|
||
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
|
||
<script>window.jQuery || document.write('<script src="/docs/4.1/assets/js/vendor/jquery-slim.min.js"><\/script>')</script>
|
||
|
||
<script src="/docs/4.1/assets/js/vendor/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script><script src="/docs/4.1/dist/js/bootstrap.min.js" integrity="sha384-smHYKdLADwkXOn1EmN1qk/HfnUcbVRZyYmZ4qpPea6sjB/pTJ0euyQp0Mk8ck+5T" crossorigin="anonymous"></script><script src="https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.js"></script><script src="/docs/4.1/assets/js/docs.min.js"></script>
|
||
</body>
|
||
</html>
|