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The most popular front-end framework for developing responsive, mobile first projects on the web.

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<div class="bs-docs-section"> <h1 id="accessibility" class="page-header">Accessibility</h1> <p class="lead">Bootstrap follows common web standards and&mdash;with minimal extra effort&mdash;can be used to create sites that are accessible to those using <abbr title="Assistive Technology" class="initialism">AT</abbr>.</p> <h3>Skip navigation</h3> <p>If your navigation contains many links and comes before the main content in the DOM, add a <code>Skip to main content</code> link before the navigation <a href="http://a11yproject.com/posts/skip-nav-links/">(read why)</a>. Using the <code>.sr-only</code> class will visually hide the skip link, and the <code>.sr-only-focusable</code> class will ensure that the link becomes visible once focused (for sighted keyboard users).</p> {% highlight html %} <body> <a href="#content" class="sr-only sr-only-focusable">Skip to main content</a> ... <div class="container" id="content"> <!-- The main page content --> </div> </body> {% endhighlight %} <h3>Nested headings</h3> <p>When nesting headings (<code>&lt;h1&gt;</code> - <code>&lt;h6&gt;</code>), your primary document header should be an <code>&lt;h1&gt;</code>. Subsequent headings should make logical use of <code>&lt;h2&gt;</code> - <code>&lt;h6&gt;</code> such that screen readers can construct a table of contents for your pages.</p> <p>Learn more at <a href="http://squizlabs.github.io/HTML_CodeSniffer/Standards/Section508/">HTML CodeSniffer</a> and <a href="http://accessibility.psu.edu/headings">Penn State's AccessAbility</a>.</p> <h3>Color contrast</h3> <p>Currently, some of the default color combinations available in Bootstrap (such as the various <a href="../css/#buttons">styled button</a> classes, some of the code highlighting colors used for <a href="../css/#code-block">basic code blocks</a>, the <code>.bg-primary</code> <a href="../css/#helper-classes-backgrounds">contextual background</a> helper class, and the default link color when used on a white background) have a low contrast ratio (below the <a href="http://www.w3.org/TR/WCAG20/#visual-audio-contrast-contrast">recommended ratio of 4.5:1</a>). This can cause problems to users with low vision or who are color blind. These default colors may need to be modified to increase their contrast and legibility.</p> <h3>Additional resources</h3> <ul> <li><a href="https://github.com/squizlabs/HTML_CodeSniffer">"HTML Codesniffer" bookmarklet for identifying accessibility issues</a></li> <li><a href="https://chrome.google.com/webstore/detail/accessibility-developer-t/fpkknkljclfencbdbgkenhalefipecmb?hl=en">Chrome's Accessibility Developer Tools extension</a></li> <li><a href="http://www.paciellogroup.com/resources/contrastanalyser/">Colour Contrast Analyser</a> <li><a href="http://a11yproject.com/">The A11Y Project</a></li> <li><a href="https://developer.mozilla.org/en-US/docs/Accessibility">MDN accessibility documentation</a></li> </ul> </div>