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Accessibility

A brief overview of Boosted’s features and limitations for the creation of accessible content.

Boosted provides an easy-to-use framework of ready-made styles, layout tools, and interactive components, allowing developers to create websites and applications that are visually appealing, functionally rich, and accessible out of the box.

Overview and Limitations

The overall accessibility of any project built with Boosted depends in large part on the author’s markup, additional styling, and scripting they’ve included. However, provided that these have been implemented correctly, it should be perfectly possible to create websites and applications with Boosted that fulfill WCAG 2.1 (A/AA/AAA), Section 508 and similar accessibility standards and requirements.

Structural markup

Boosted’s styling and layout can be applied to a wide range of markup structures. This documentation aims to provide developers with best practice examples to demonstrate the use of Boosted itself and illustrate appropriate semantic markup, including ways in which potential accessibility concerns can be addressed.

Interactive components

Boosted’s interactive components—such as modal dialogs, dropdown menus and custom tooltips—are designed to work for touch, mouse and keyboard users. Through the use of relevant WAI-ARIA roles and attributes, these components should also be understandable and operable using assistive technologies (such as screen readers).

Because Boosted’s components are purposely designed to be fairly generic, authors may need to include further ARIA roles and attributes, as well as JavaScript behavior, to more accurately convey the precise nature and functionality of their component. This is usually noted in the documentation.

Color contrast

Some combinations of colors that currently make up Boosted’s default palette—used throughout the framework for things such as button variations, alert variations, form validation indicators—may lead to insufficient color contrast (below the recommended WCAG 2.1 text color contrast ratio of 4.5:1 and the WCAG 2.1 non-text color contrast ratio of 3:1), particularly when used against a light background. Authors are encouraged to test their specific uses of color and, where necessary, manually modify/extend these default colors to ensure adequate color contrast ratios.

Ensuring contrasts

Each of the text colors shown are combined with background colors from the Orange digital palette in order to meet WCAG 2.1 accessibility standards for color contrast. Please note that contrasts are locked when using .text-* and .bg-* utilities, to ensure sufficient contrasts.

Core colors contrasts
Core colors	Text color	Pass level
#000	#ff7900	AAA
	#fff	AAA
	#999	AAA
#fff	#f16e00	AA Large text
	#000	AAA
	#666	AA AAA Large text
#ff7900	#000	AAA
#f16e00	#fff	AA Large text
#595959	#fff	AAA

Functional greys contrasts
Functional greys	Text color	Pass level
#333	#fff	AAA
#666	#fff	AA AAA Large text
#999	#000	AAA
#ccc	#000	AAA
#ddd	#000	AAA
#eee	#000	AAA

Supporting colors contrasts
Supporting colors	Text color	Pass level
#4bb4e6	#000	AAA
#50beb7	#000	AAA
#ffb4e6	#000	AAA
#a885d8	#000	AAA
#ffd200	#000	AAA

Functional colors contrasts
Functional colors	Text color	Pass level
#32c832	#000	AAA
#527edb	#000	AA AAA Large text
#527edb	#fff	AA Large text
#fc0	#000	AAA
#cd3c14	#000	AA Large text
#cd3c14	#fff	AA AAA Large text

Content which should be visually hidden, but remain accessible to assistive technologies such as screen readers, can be styled using the .sr-only class. This can be useful in situations where additional visual information or cues (such as meaning denoted through the use of color) need to also be conveyed to non-visual users.

<p class="text-danger">
  <span class="sr-only">Danger: </span>
  This action is not reversible
</p>

For visually hidden interactive controls, such as traditional “skip” links, .sr-only can be combined with the .sr-only-focusable class. This will ensure that the control becomes visible once focused (for sighted keyboard users).

<a class="sr-only sr-only-focusable" href="#content">Skip to main content</a>

Reduced motion

Boosted includes support for the prefers-reduced-motion media feature. In browsers/environments that allow the user to specify their preference for reduced motion, most CSS transition effects in Boosted (for instance, when a modal dialog is opened or closed, or the sliding animation in carousels) will be disabled, and meaningful animations (such as spinners) will be slowed down.

Focus visibility

Boosted includes a focus-visible polyfill to ensure an enhanced focus visibility for keyboard users while shutting down focus styles on active state.

Maximum line length

When writing a paragraph, it is commonly admitted that a line should have 80 characters as a maximum. This phenomenon is carefully explained in the C20 technique: Using relative measurements to set column widths.

For more information, please read text utilities.