View on GitHub

Buttons

Use Boosted Innovation Cup’s custom button styles for actions in forms, dialogs, and more with support for multiple sizes, states, and more.

On this page

Examples

Boosted Innovation Cup includes several predefined button styles, each serving its own semantic purpose, with a few extras thrown in for more control.

html

<button type="button" class="btn btn-primary">Primary</button>
<button type="button" class="btn btn-secondary">Secondary</button>
<button type="button" class="btn btn-success">Success</button>
<button type="button" class="btn btn-danger">Danger</button>
<button type="button" class="btn btn-warning">Warning</button>
<button type="button" class="btn btn-info">Info</button>
<button type="button" class="btn btn-light">Light</button>
<button type="button" class="btn btn-dark">Dark</button>

<button type="button" class="btn btn-link">Link</button>

Conveying meaning to assistive technologies

Using color to add meaning only provides a visual indication, which will not be conveyed to users of assistive technologies – such as screen readers. Ensure that information denoted by the color is either obvious from the content itself (e.g. the visible text), or is included through alternative means, such as additional text hidden with the .visually-hidden class.

With icon

The recommended way of using an icon in a button is an embedded SVG. You need to:

set its dimensions to 1.25rem to match button size—except for .btn-sm where you should use 1rem,
apply .me-1 on it to get consistent spacing,
fill it using currentColor to respect button color scheme,
finally add .overflow-visible utility to prevent SVG content from being cropped.

html

<button type="button" class="btn btn-primary btn-sm">
  <svg width="1rem" height="1rem" fill="currentColor" aria-hidden="true" focusable="false" class="me-1 overflow-visible">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  Primary
</button>
<button type="button" class="btn btn-primary">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false" class="me-1">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  Primary
</button>
<button type="button" class="btn btn-primary btn-lg">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false" class="me-1 overflow-visible">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  Primary
</button>

Icon only

Add .btn-icon to get a squared button, meant to only contain an icon. Make sure to provide an accessible name to your button, either using a .visually-hidden content or a aria-label attribute.

html

<button type="button" class="btn btn-icon btn-secondary btn-sm">
  <svg width="1rem" height="1rem" fill="currentColor" aria-hidden="true" focusable="false" class="overflow-visible">
   <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">Secondary</span>
</button>
<button type="button" class="btn btn-icon btn-secondary">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">Secondary</span>
</button>
<button type="button" class="btn btn-icon btn-secondary btn-lg">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false" class="overflow-visible">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">Secondary</span>
</button>

No outline

Use .btn-no-outline to get a borderless button as default state, and a consistent gray border for other states.

html

<button type="button" class="btn btn-icon btn-no-outline btn-sm">
  <svg width="1rem" height="1rem" fill="currentColor" aria-hidden="true" focusable="false" class="overflow-visible">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">No outline</span>
</button>
<button type="button" class="btn btn-icon btn-no-outline">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">No outline</span>
</button>
<button type="button" class="btn btn-icon btn-no-outline btn-lg">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false" class="overflow-visible">
   <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">No outline</span>
</button>

Use .btn-social to get a rounded button meant to display contact points links or actions. Use one of our modifier to specify a network. Make sure to provide an accessible name to your button, either using a .visually-hidden content or a aria-label attribute.

html

<a href="#" class="btn btn-icon btn-social btn-twitter"><span class="visually-hidden">Twitter</span></a>
<a href="#" class="btn btn-icon btn-social btn-facebook"><span class="visually-hidden">Facebook</span></a>
<a href="#" class="btn btn-icon btn-social btn-instagram"><span class="visually-hidden">Instagram</span></a>
<a href="#" class="btn btn-icon btn-social btn-whatsapp"><span class="visually-hidden">Whatsapp</span></a>
<a href="#" class="btn btn-icon btn-social btn-linkedin"><span class="visually-hidden">LinkedIn</span></a>
<a href="#" class="btn btn-icon btn-social btn-youtube"><span class="visually-hidden">YouTube</span></a>
<a href="#" class="btn btn-icon btn-social btn-snapchat"><span class="visually-hidden">Snapchat</span></a>
<a href="#" class="btn btn-icon btn-social btn-pinterest"><span class="visually-hidden">Pinterest</span></a>
<a href="#" class="btn btn-icon btn-social btn-mail"><span class="visually-hidden">Mail</span></a>

Supported social networks are declared in a dedicated Sass map—meaning you’re able to add or remove a network from the following map.

$btn-social-networks: (
  "facebook": (
    "color": #3b5998,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M19 6h5V0h-5c-4 0-7 3-7 7v3H8v6h4v16h6V16h5l1-6h-6V7l1-1z'></path></svg>"
  ),
  "twitter": (
    "color": #1da1f2,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M32 7a13 13 0 01-3.8 1.1 6.6 6.6 0 003-3.6c-1.4.7-2.8 1.3-4.3 1.6a6.6 6.6 0 00-11.1 6A18.6 18.6 0 012.2 5a6.6 6.6 0 002 8.9c-1 0-2-.4-3-.9v.1c0 3.2 2.4 5.9 5.4 6.5a6.6 6.6 0 01-3 0 6.6 6.6 0 006.1 4.6A13.2 13.2 0 010 27.1a18.6 18.6 0 0028.7-16.6C30 9.5 31.1 8.4 32 7z'/></svg>"
  ),
  "instagram": (
    "color": #e1306c,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M16 2.9h6.5c1.5.1 2.4.4 3 .6a5 5 0 011.8 1.2c.5.6.9 1.1 1.2 1.9.2.5.4 1.4.5 3a112.7 112.7 0 01-.5 15.8 5 5 0 01-1.2 1.9c-.6.5-1.1.9-1.9 1.2-.5.2-1.4.4-3 .5a112.7 112.7 0 01-15.8-.5 5 5 0 01-1.9-1.2 5 5 0 01-1.2-1.9c-.2-.5-.4-1.4-.5-3a112.7 112.7 0 01.5-15.8 5 5 0 011.2-1.9c.6-.5 1.1-.9 1.9-1.2C7 3.3 8 3 9.6 3l6.4-.1zM16 0H9.4C7.7.3 6.5.5 5.5.9s-2 1-2.8 1.9c-1 .9-1.5 1.8-1.9 2.8-.4 1-.6 2.2-.7 3.9a117.6 117.6 0 00.7 17c.5 1.1 1 2 1.9 3 .9.8 1.8 1.4 2.8 1.8 1 .4 2.2.6 3.9.7a117.2 117.2 0 0017-.7c1.1-.4 2-1 2.9-1.9s1.4-1.8 1.8-2.8c.4-1 .7-2.2.8-3.9a117.2 117.2 0 00-.8-17A7.8 7.8 0 0026.4.8c-1-.5-2.1-.7-3.8-.8L16 0z'/><path d='M16 7.8a8.2 8.2 0 100 16.4 8.2 8.2 0 000-16.4zm0 13.5a5.3 5.3 0 110-10.6 5.3 5.3 0 010 10.6zM26.5 7.5a2 2 0 11-3.9 0 2 2 0 013.9 0z'/></svg>"
  ),
  "youtube": (
    "color": #f00,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M31.7 9.6s-.3-2.2-1.3-3.2c-1.2-1.3-2.6-1.3-3.2-1.3-4.5-.4-11.2-.4-11.2-.4s-6.7 0-11.2.4c-.6 0-2 0-3.2 1.3C.6 7.4.3 9.6.3 9.6S0 12.2 0 14.8v2.4c0 2.6.3 5.2.3 5.2s.3 2.2 1.3 3.2c1.2 1.2 2.8 1.2 3.5 1.3 2.6.3 11 .4 11 .4s6.6 0 11.1-.4c.6 0 2 0 3.2-1.3 1-1 1.3-3.2 1.3-3.2s.3-2.6.3-5.2v-2.4c0-2.6-.3-5.2-.3-5.2zm-19 10.5v-9l8.6 4.6-8.6 4.4z'/></svg>"
  ),
  "linkedin": (
    "color": #0077b5,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M12 12h5.5v2.8h.1a6.1 6.1 0 015.5-2.8c5.8 0 6.9 3.6 6.9 8.4V30h-5.8v-8.5c0-2 0-4.7-3-4.7s-3.4 2.2-3.4 4.5V30H12V12zM2 12h6v18H2V12zm6-5a3 3 0 11-6 0 3 3 0 016 0z'/></svg>",
  ),
  "whatsapp": (
    "color": #25d366,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M27.3 4.7a15.9 15.9 0 00-25 19.1L.1 32l8.4-2.2A15.9 15.9 0 0027.3 4.7zM16 29c-2.4 0-4.7-.6-6.7-1.8l-.5-.3-5 1.3 1.3-4.8-.3-.5A13.2 13.2 0 1116.1 29zm7.2-9.8l-2.7-1.3c-.3-.1-.6-.2-1 .2l-1.2 1.5c-.2.3-.4.3-.8.1s-1.7-.6-3.2-2c-1.2-1-2-2.3-2.2-2.7s0-.6.2-.8l.6-.7.4-.6v-.7l-1.3-3c-.3-.7-.6-.6-.9-.7h-.7c-.2 0-.7.1-1.1.5C9 9.4 8 10.4 8 12.3s1.4 3.9 1.6 4.1c.2.3 2.8 4.3 6.8 6l2.3.9c.9.3 1.8.2 2.4.1.8-.1 2.4-1 2.7-1.9s.4-1.7.3-1.9l-.8-.4z'/></svg>"
  ),
  "mail": (
    "color": $primary,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M3.2 14.3c0 9.5 0 9 .2 9.5.3.8 1 1.4 1.7 1.7l12.2.1h11.5v-8.8c0-9.3 0-8.9-.2-9.3-.2-.7-.7-1.2-1.3-1.6l-.8-.3H3.2v8.7zm22.9-2.4a246.2 246.2 0 01-4.9 4.7l-.8.7-.5.6-.7.6c-.6.6-1 .9-1.3 1a4 4 0 01-1.8.5 4 4 0 01-2.4-.6 13 13 0 01-1.9-1.7l-2.4-2.4-.6-.6-1.4-1.3L6.1 12l-.5-.5V8.9l.6.5L7.9 11l1.4 1.4 1.3 1.2 1.3 1.3a195 195 0 012.6 2.4c.4.3 1 .5 1.6.4.5 0 1-.1 1.4-.4L19 16l1-1 1-1a214.7 214.7 0 012.2-2l1-1 2-2 .2-.2v2.8l-.3.3z'/></svg>",
    "size": 1.5rem
  ),
  "snapchat": (
    "color": #fffc00,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 26 28'><path d='M13 2c3 0 5 2 7 4v6h2l1 1-3 2v1l4 4h1l1 1-4 1-1 2h-2-1c-1 0-2 2-5 2s-4-2-5-2H5l-1-2-4-1 1-1h1l4-4v-1l-3-2 1-1h2V9 6c2-3 4-4 7-4z'/></svg>"
  ),
  "pinterest": (
    "color": red,
    "icon": "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><path d='M16 2a14 14 0 00-5 27v-4l2-7-1-2c0-2 1-3 3-3l1 2-1 4c0 2 1 3 2 3 3 0 5-3 5-7 0-3-3-5-6-5-4 0-6 3-6 6l1 3a302 302 0 01-1 2c-2-1-3-3-3-5 0-5 3-9 9-9 5 0 9 4 9 8 0 5-3 9-7 9l-4-2v4l-2 3a14 14 0 0018-13c0-8-6-14-14-14z'/></svg>",
    "size": 1.375rem
  )
);

Dark variant

Add .btn-inverse to the .btn for a dark variant.

html

<button type="button" class="btn btn-inverse btn-primary">Primary</button>
<button type="button" class="btn btn-inverse btn-secondary">Secondary</button>
<button type="button" class="btn btn-inverse btn-success">Success</button>
<button type="button" class="btn btn-inverse btn-danger">Danger</button>
<button type="button" class="btn btn-inverse btn-warning">Warning</button>
<button type="button" class="btn btn-inverse btn-info">Info</button>
<button type="button" class="btn btn-inverse btn-light">Light</button>
<button type="button" class="btn btn-inverse btn-dark">Dark</button>

<button type="button" class="btn btn-inverse btn-link">Link</button>

html

<button type="button" class="btn btn-inverse btn-primary">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false" class="me-1">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  Primary
</button>
<button type="button" class="btn btn-icon btn-inverse btn-secondary">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">Secondary</span>
</button>
<button type="button" class="btn btn-icon btn-inverse btn-no-outline">
  <svg width="1.25rem" height="1.25rem" fill="currentColor" aria-hidden="true" focusable="false">
    <use xlink:href="/innovation-cup/docs/0.2/assets/img/boosted-sprite.svg#success"/>
  </svg>
  <span class="visually-hidden">No outline</span>
</button>

html

<a href="#" class="btn btn-icon btn-inverse btn-social btn-twitter"><span class="visually-hidden">Twitter</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-facebook"><span class="visually-hidden">Facebook</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-instagram"><span class="visually-hidden">Instagram</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-whatsapp"><span class="visually-hidden">Whatsapp</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-linkedin"><span class="visually-hidden">LinkedIn</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-youtube"><span class="visually-hidden">YouTube</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-snapchat"><span class="visually-hidden">Snapchat</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-pinterest"><span class="visually-hidden">Pinterest</span></a>
<a href="#" class="btn btn-icon btn-inverse btn-social btn-mail"><span class="visually-hidden">Mail</span></a>

Disable text wrapping

If you don’t want the button text to wrap, you can add the .text-nowrap class to the button. In Sass, you can set $btn-white-space: nowrap to disable text wrapping for each button.

Button tags

The .btn classes are designed to be used with the <button> element. However, you can also use these classes on <a> or <input> elements (though some browsers may apply a slightly different rendering).

When using button classes on <a> elements that are used to trigger in-page functionality (like collapsing content), rather than linking to new pages or sections within the current page, these links should be given a role="button" to appropriately convey their purpose to assistive technologies such as screen readers.

Link

html

<a class="btn btn-primary" href="#" role="button">Link</a>
<button class="btn btn-primary" type="submit">Button</button>
<input class="btn btn-primary" type="button" value="Input">
<input class="btn btn-primary" type="submit" value="Submit">
<input class="btn btn-primary" type="reset" value="Reset">

Sizes

Fancy larger or smaller buttons? Add .btn-lg or .btn-sm for additional sizes.

html

<button type="button" class="btn btn-primary btn-lg">Large button</button>
<button type="button" class="btn btn-secondary btn-lg">Large button</button>

html

<button type="button" class="btn btn-primary btn-sm">Small button</button>
<button type="button" class="btn btn-secondary btn-sm">Small button</button>

You can even roll your own custom sizing with CSS variables:

html

<button type="button" class="btn btn-primary"
        style="--bs-btn-padding-y: .25rem; --bs-btn-padding-x: .5rem; --bs-btn-font-size: .75rem;">
  Custom button
</button>

Disabled state

Make buttons look inactive by adding the disabled boolean attribute to any <button> element. Disabled buttons have pointer-events: none applied to, preventing hover and active states from triggering.

html

<button type="button" class="btn btn-primary" disabled>Primary button</button>
<button type="button" class="btn btn-secondary" disabled>Button</button>

Disabled buttons using the <a> element behave a bit different:

<a>s don’t support the disabled attribute, so you must add the .disabled class to make it visually appear disabled.
Some future-friendly styles are included to disable all pointer-events on anchor buttons.
Disabled buttons using <a> should include the aria-disabled="true" attribute to indicate the state of the element to assistive technologies.
Disabled buttons using <a> should not include the href attribute.

Primary link Link

html

<a class="btn btn-primary disabled" role="button" aria-disabled="true">Primary link</a>
<a class="btn btn-secondary disabled" role="button" aria-disabled="true">Link</a>

Link functionality caveat

To cover cases where you have to keep the href attribute on a disabled link, the .disabled class uses pointer-events: none to try to disable the link functionality of <a>s. Note that this CSS property is not yet standardized for HTML, but all modern browsers support it. In addition, even in browsers that do support pointer-events: none, keyboard navigation remains unaffected, meaning that sighted keyboard users and users of assistive technologies will still be able to activate these links. So to be safe, in addition to aria-disabled="true", also include a tabindex="-1" attribute on these links to prevent them from receiving keyboard focus, and use custom JavaScript to disable their functionality altogether.

Primary link Link

html

<a href="#" class="btn btn-primary disabled" tabindex="-1" role="button" aria-disabled="true">Primary link</a>
<a href="#" class="btn btn-secondary disabled" tabindex="-1" role="button" aria-disabled="true">Link</a>

Block buttons

Create responsive stacks of full-width, “block buttons” with a mix of our display and gap utilities. By using utilities instead of button specific classes, we have much greater control over spacing, alignment, and responsive behaviors.

html

<div class="d-grid gap-2">
  <button class="btn btn-primary" type="button">Button</button>
  <button class="btn btn-primary" type="button">Button</button>
</div>

Here we create a responsive variation, starting with vertically stacked buttons until the md breakpoint, where .d-md-block replaces the .d-grid class, thus nullifying the gap-2 utility. Resize your browser to see them change.

html

<div class="d-grid gap-2 d-md-block">
  <button class="btn btn-primary" type="button">Button</button>
  <button class="btn btn-primary" type="button">Button</button>
</div>

You can adjust the width of your block buttons with grid column width classes. For example, for a half-width “block button”, use .col-6. Center it horizontally with .mx-auto, too.

html

<div class="d-grid gap-2 col-6 mx-auto">
  <button class="btn btn-primary" type="button">Button</button>
  <button class="btn btn-primary" type="button">Button</button>
</div>

Additional utilities can be used to adjust the alignment of buttons when horizontal. Here we’ve taken our previous responsive example and added some flex utilities and a margin utility on the button to right align the buttons when they’re no longer stacked.

html

<div class="d-grid gap-2 d-md-flex justify-content-md-end">
  <button class="btn btn-primary me-md-2" type="button">Button</button>
  <button class="btn btn-primary" type="button">Button</button>
</div>

Button plugin

The button plugin allows you to create simple on/off toggle buttons.

Visually, these toggle buttons are identical to the checkbox toggle buttons. However, they are conveyed differently by assistive technologies: the checkbox toggles will be announced by screen readers as “checked”/“not checked” (since, despite their appearance, they are fundamentally still checkboxes), whereas these toggle buttons will be announced as “button”/“button pressed”. The choice between these two approaches will depend on the type of toggle you are creating, and whether or not the toggle will make sense to users when announced as a checkbox or as an actual button.

Toggle states

Add data-bs-toggle="button" to toggle a button’s active state. If you’re pre-toggling a button, you must manually add the .active class and aria-pressed="true" to ensure that it is conveyed appropriately to assistive technologies.

html

<button type="button" class="btn btn-primary" data-bs-toggle="button">Toggle button</button>
<button type="button" class="btn btn-primary active" data-bs-toggle="button" aria-pressed="true">Active toggle button</button>
<button type="button" class="btn btn-primary" disabled data-bs-toggle="button">Disabled toggle button</button>

Toggle link Active toggle link Disabled toggle link

html

<a href="#" class="btn btn-primary" role="button" data-bs-toggle="button">Toggle link</a>
<a href="#" class="btn btn-primary active" role="button" data-bs-toggle="button" aria-pressed="true">Active toggle link</a>
<a class="btn btn-primary disabled" aria-disabled="true" role="button" data-bs-toggle="button">Disabled toggle link</a>

Methods

You can create a button instance with the button constructor, for example:

const bsButton = new boosted.Button('#myButton')

Method	Description
`dispose`	Destroys an element’s button. (Removes stored data on the DOM element)
`getInstance`	Static method which allows you to get the button instance associated to a DOM element, you can use it like this: `boosted.Button.getInstance(element)`.
`getOrCreateInstance`	Static method which returns a button instance associated to a DOM element or create a new one in case it wasn’t initialized. You can use it like this: `boosted.Button.getOrCreateInstance(element)`.
`toggle`	Toggles push state. Gives the button the appearance that it has been activated.

For example, to toggle all buttons

document.querySelectorAll('.btn').forEach(buttonElement => {
  const button = boosted.Button.getOrCreateInstance(buttonElement)
  button.toggle()
})

CSS

Variables

As part of Boosted’s evolving CSS variables approach, buttons now use local CSS variables on .btn for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too.

  --#{$prefix}btn-padding-x: #{$btn-padding-x};
  --#{$prefix}btn-padding-y: #{$btn-padding-y};
  --#{$prefix}btn-font-family: #{$btn-font-family};
  @include rfs($btn-font-size, --#{$prefix}btn-font-size);
  --#{$prefix}btn-font-weight: #{$btn-font-weight};
  --#{$prefix}btn-line-height: #{$btn-line-height};
  --#{$prefix}btn-color: #{$body-color};
  --#{$prefix}btn-bg: transparent;
  --#{$prefix}btn-border-width: #{$btn-border-width};
  --#{$prefix}btn-border-color: transparent;
  --#{$prefix}btn-border-radius: #{$btn-border-radius};
  --#{$prefix}btn-hover-border-color: initial; // Boosted mod
  --#{$prefix}btn-box-shadow: #{$btn-box-shadow};
  --#{$prefix}btn-disabled-opacity: #{$btn-disabled-opacity};
  --#{$prefix}btn-focus-box-shadow: 0 0 0 #{$btn-focus-width} var(--#{$prefix}btn-focus-shadow-rgb); // Boosted mod
  --#{$boosted-prefix}icon-spacing: #{$btn-icon-padding-x}; // Boosted mod

Each .btn-* modifier class updates the appropriate CSS variables to minimize additional CSS rules with our button-variant() and button-size() mixins.

Sass variables

$btn-padding-y:               $input-btn-padding-y;
$btn-padding-x:               $input-btn-padding-x;
$btn-font-family:             $input-btn-font-family;
$btn-font-size:               $input-btn-font-size;
$btn-line-height:             $input-btn-line-height;
$btn-white-space:             null; // Set to `nowrap` to prevent text wrapping

$btn-padding-y-sm:            $input-btn-padding-y-sm;
$btn-padding-x-sm:            $input-btn-padding-x-sm;
$btn-font-size-sm:            $input-btn-font-size-sm;
$btn-line-height-sm:          $line-height-sm; // Boosted mod

$btn-padding-y-lg:            $input-btn-padding-y-lg;
$btn-padding-x-lg:            $input-btn-padding-x-lg;
$btn-font-size-lg:            $input-btn-font-size-lg;
$btn-line-height-lg:          $h5-line-height; // Boosted mod

$btn-border-width:            $input-btn-border-width;

$btn-font-weight:             $font-weight-bold;
$btn-box-shadow:              null;
$btn-focus-width:             $border-width;
$btn-focus-box-shadow:        0 0 0 $btn-focus-width $white;
$btn-disabled-opacity:        1;
$btn-active-box-shadow:       null;

$btn-link-color:              var(--#{$prefix}link-color);
$btn-link-hover-color:        var(--#{$prefix}link-hover-color);
$btn-link-disabled-color:     $gray-500;

// Allows for customizing button radius independently from global border radius
$btn-border-radius:           $border-radius;
$btn-border-radius-sm:        $border-radius-sm;
$btn-border-radius-lg:        $border-radius-lg;

$btn-transition:              $transition-focus;

Sass mixins

There are three mixins for buttons: button mixins (based on $theme-colors), a button size mixin and a button icon mixin.

@mixin button-variant(
  $background,
  $border,
  $color: color-contrast($background),
  $hover-background: $black, // Boosted mod
  $hover-border: $black, // Boosted mod
  $hover-color: color-contrast($hover-background),
  $active-background: $primary, // Boosted mod
  $active-border: $primary, // Boosted mod
  $active-color: color-contrast($active-background),
  $disabled-background: $gray-500, // Boosted mod
  $disabled-border: $gray-500, // Boosted mod
  $disabled-color: $white, // Boosted mod
  $btn-focus-shadow-color: $white // Boosted mod
) {
  --#{$prefix}btn-color: #{$color};
  --#{$prefix}btn-bg: #{$background};
  --#{$prefix}btn-border-color: #{$border};
  --#{$prefix}btn-hover-color: #{$hover-color};
  --#{$prefix}btn-hover-bg: #{$hover-background};
  --#{$prefix}btn-hover-border-color: #{$hover-border};
  --#{$prefix}btn-focus-shadow-rgb: #{$btn-focus-shadow-color}; // Boosted mod
  --#{$prefix}btn-active-color: #{$active-color};
  --#{$prefix}btn-active-bg: #{$active-background};
  --#{$prefix}btn-active-border-color: #{$active-border};
  // Boosted mod: no definition of --#{$prefix}btn-active-shadow
  --#{$prefix}btn-disabled-color: #{$disabled-color};
  --#{$prefix}btn-disabled-bg: #{$disabled-background};
  --#{$prefix}btn-disabled-border-color: #{$disabled-border};
}

@mixin button-size($padding-y, $padding-x, $font-size, $border-radius, $line-height: null, $icon-spacing: $btn-icon-padding-x) {
  --#{$boosted-prefix}icon-spacing: #{$icon-spacing}; // Boosted mod: used for icons
  --#{$prefix}btn-padding-y: #{$padding-y};
  --#{$prefix}btn-padding-x: #{$padding-x};
  @include rfs($font-size, --#{$prefix}btn-font-size);
  line-height: $line-height; // Boosted mod
  --#{$prefix}btn-border-radius: #{$border-radius};
}

@mixin button-icon(
  $icon,
  $width: $spacer,
  $height: $width,
  $size: $width $height,
  $pseudo: "before",
  $selector: &,
  $position: 50%
) {
  min-width: $width;
  min-height: $height;

  @at-root #{$selector} {
    &::#{$pseudo} {
      display: block;
      min-width: inherit;
      min-height: inherit;
      content: "";
      background-color: currentcolor;
      -webkit-mask: #{$icon} no-repeat #{$position} / #{$size}; // stylelint-disable-line property-no-vendor-prefix
      mask: #{$icon} no-repeat #{$position} / #{$size};
    }
  }
}

Sass loops

Button variants (for regular and outline buttons) use their respective mixins with our $theme-colors map to generate the modifier classes in scss/_buttons.scss.

.btn-primary,
.btn-warning {
  @include button-variant($primary, $primary, $active-background: $white, $active-border: $black);
  &.btn-inverse {
    @include button-variant($primary, $primary, $black, $white, $white, $black, $black, $white, $white, $gray-700, $gray-700, $black, $black);
  }
}

.btn-light,
.btn-secondary {
  @include button-variant($white, $black, $disabled-background: $white, $disabled-border: $gray-500, $disabled-color: $gray-500);
  &.btn-inverse {
    @include button-variant($black, $white, $white, $white, $white, $black, $primary, $primary, $black, transparent, $gray-700, $gray-700, $black);
  }
}

.btn-success {
  @include button-variant($success, $success);
  &.btn-inverse {
    @include button-variant($success, $success, $black,  $white, $white, $black, $primary, $primary, $black, $gray-700, $gray-700, $black, $black);
  }
}

.btn-info,
.btn-dark {
  @include button-variant($black, $black, $white, $white, $black, $black);
  &.btn-inverse {
    @include button-variant($white, $white, $black, $black, $white, $white, $primary, $primary, $black, $gray-700, $gray-700, $black, $black);
  }
}

.btn-danger {
  @include button-variant($danger, $danger);
  &.btn-inverse {
    @include button-variant($danger, $danger, $black, $white, $white, $black, $primary, $primary, $black, $gray-700, $gray-700, $black, $black);
  }
}

Buttons

Examples

Conveying meaning to assistive technologies

With icon

Icon only

No outline

Social buttons

Dark variant

Disable text wrapping

Button tags

Sizes

Disabled state

Link functionality caveat

Block buttons

Button plugin

Toggle states

Methods

CSS

Variables

Sass variables

Sass mixins

Sass loops