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You can support our Open Source software development in the following ways:

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Borders

Use border utilities to quickly style the border and border-radius of an element. Great for images, buttons, or any other element.

Border

Use border utilities to add or remove an element’s borders. Choose from all borders or one at a time.

Additive

<span class="border"></span>
<span class="border-top"></span>
<span class="border-end"></span>
<span class="border-bottom"></span>
<span class="border-start"></span>

Subtractive

Or remove borders:

<span class="border border-0"></span>
<span class="border border-top-0"></span>
<span class="border border-end-0"></span>
<span class="border border-bottom-0"></span>
<span class="border border-start-0"></span>

Color

Change the border color using utilities built on our theme colors.

<span class="border border-primary"></span>
<span class="border border-secondary"></span>
<span class="border border-success"></span>
<span class="border border-danger"></span>
<span class="border border-warning"></span>
<span class="border border-info"></span>
<span class="border border-light"></span>
<span class="border border-dark"></span>
<span class="border border-white"></span>

Using utilities you can change the border on one side only, or you can change all borders to make them different colors.

<span class="border-top border-top-primary"></span>
<span class="border-end border-end-primary"></span>
<span class="border-bottom border-bottom-primary"></span>
<span class="border-start border-start-primary"></span>
<span class="border-start border-start-primary border-end border-end-danger"></span>
<span class="border-top border-top-primary border-end border-end-danger border-bottom border-bottom-success"></span>
<span class="border border-top-primary border-end-danger border-bottom-success border-start-info"></span>

Border-width

Or modify the default border-color of a component:

Dangerous heading
Changing border color and width
<div class="mb-4">
  <label for="exampleFormControlInput1" class="form-label">Email address</label>
  <input type="email" class="form-control border-success" id="exampleFormControlInput1" placeholder="[email protected]">
</div>

<div class="h4 pb-2 mb-4 text-danger border-bottom border-danger">
  Dangerous heading
</div>

<div class="p-3 bg-info bg-opacity-10 border border-info border-start-0 rounded-end">
  Changing border color and width
</div>

Opacity

Added in v4.2.0

Bootstrap border-{color} utilities are generated with Sass using CSS variables. This allows for real-time color changes without compilation and dynamic alpha transparency changes.

How it works

Consider our default .border-success utility.

.border-success {
  --cui-border-opacity: 1;
  border-color: rgba(var(--cui-success-rgb), var(--cui-border-opacity)) !important;
}

We use an RGB version of our --cui-success (with the value of 25, 135, 84) CSS variable and attached a second CSS variable, --cui-border-opacity, for the alpha transparency (with a default value 1 thanks to a local CSS variable). That means anytime you use .border-success now, your computed color value is rgba(25, 135, 84, 1). The local CSS variable inside each .border-* class avoids inheritance issues so nested instances of the utilities don’t automatically have a modified alpha transparency.

Example

To change that opacity, override --cui-border-opacity via custom styles or inline styles.

This is default success border
This is 50% opacity success border
<div class="border border-success p-2 mb-2">This is default success border</div>
<div class="border border-success p-2" style="--cui-border-opacity: .5;">This is 50% opacity success border</div>

Or, choose from any of the .border-opacity utilities:

This is default success border
This is 75% opacity success border
This is 50% opacity success border
This is 25% opacity success border
This is 10% opacity success border
<div class="border border-success p-2 mb-2">This is default success border</div>
<div class="border border-success p-2 mb-2 border-opacity-75">This is 75% opacity success border</div>
<div class="border border-success p-2 mb-2 border-opacity-50">This is 50% opacity success border</div>
<div class="border border-success p-2 mb-2 border-opacity-25">This is 25% opacity success border</div>
<div class="border border-success p-2 border-opacity-10">This is 10% opacity success border</div>

Width

<span class="border border-1"></span>
<span class="border border-2"></span>
<span class="border border-3"></span>
<span class="border border-4"></span>
<span class="border border-5"></span>

<span class="border border-1 border-info"></span>
<span class="border border-2 border-info"></span>
<span class="border border-3 border-info"></span>
<span class="border border-4 border-info"></span>
<span class="border border-5 border-info"></span>

<span class="border-start border-start-1"></span>
<span class="border-start border-start-2"></span>
<span class="border-start border-start-3"></span>
<span class="border-start border-start-4"></span>
<span class="border-start border-start-5"></span>

<span class="border-start border-start-1 border-start-info"></span>
<span class="border-start border-start-2 border-start-info"></span>
<span class="border-start border-start-3 border-start-info"></span>
<span class="border-start border-start-4 border-start-info"></span>
<span class="border-start border-start-5 border-start-info"></span>

Radius

Add classes to an element to easily round its corners.

Example rounded image75x75 Example top rounded image75x75 Example right rounded image75x75 Example bottom rounded image75x75 Example left rounded image75x75 Completely round image75x75 Rounded pill image150x75
<img src="..." class="rounded" alt="...">
<img src="..." class="rounded-top" alt="...">
<img src="..." class="rounded-end" alt="...">
<img src="..." class="rounded-bottom" alt="...">
<img src="..." class="rounded-start" alt="...">
<img src="..." class="rounded-circle" alt="...">
<img src="..." class="rounded-pill" alt="...">

Sizes

Use the scaling classes for larger or smaller rounded corners. Sizes range from 0 to 5, and can be configured by modifying the utilities API.

Example non-rounded image75x75 Example small rounded image75x75 Example default rounded image75x75 Example large rounded image75x75 Example larger rounded image75x75 Example extra large rounded image75x75
<img src="..." class="rounded-0" alt="...">
<img src="..." class="rounded-1" alt="...">
<img src="..." class="rounded-2" alt="...">
<img src="..." class="rounded-3" alt="...">
<img src="..." class="rounded-4" alt="...">
<img src="..." class="rounded-5" alt="...">

CSS

Variables

  --cui-border-width: #{$border-width};
  --cui-border-style: #{$border-style};
  --cui-border-color: #{$border-color};
  --cui-border-color-translucent: #{$border-color-translucent};

  --cui-border-radius: #{$border-radius};
  --cui-border-radius-sm: #{$border-radius-sm};
  --cui-border-radius-lg: #{$border-radius-lg};
  --cui-border-radius-xl: #{$border-radius-xl};
  --cui-border-radius-2xl: #{$border-radius-2xl};
  --cui-border-radius-pill: #{$border-radius-pill};
  

Sass variables

$border-width:                1px;
$border-widths: (
  1: 1px,
  2: 2px,
  3: 3px,
  4: 4px,
  5: 5px
);

$border-style:                solid;
$border-color:                $gray-200;
$border-color-translucent:    rgba($black, .175);
$border-radius:               .375rem;
$border-radius-sm:            .25rem;
$border-radius-lg:            .5rem;
$border-radius-xl:            1rem;
$border-radius-2xl:           2rem;
$border-radius-pill:          50rem;

Sass mixins

@mixin border-radius($radius: $border-radius, $fallback-border-radius: false) {
  @if $enable-rounded {
    border-radius: valid-radius($radius);
  }
  @else if $fallback-border-radius != false {
    border-radius: $fallback-border-radius;
  }
}

@mixin border-top-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-left-radius: valid-radius($radius);
    border-top-right-radius: valid-radius($radius);
  }
}

@mixin border-end-radius($radius: $border-radius) {
  @if $enable-rounded {
    @include ltr-rtl("border-top-right-radius", valid-radius($radius));
    @include ltr-rtl("border-bottom-right-radius", valid-radius($radius));
  }
}

@mixin border-bottom-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-bottom-right-radius: valid-radius($radius);
    border-bottom-left-radius: valid-radius($radius);
  }
}

@mixin border-start-radius($radius: $border-radius) {
  @if $enable-rounded {
    @include ltr-rtl("border-top-left-radius", valid-radius($radius));
    @include ltr-rtl("border-bottom-left-radius", valid-radius($radius));
  }
}

@mixin border-top-start-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-left-radius: valid-radius($radius);
  }
}

@mixin border-top-end-radius($radius: $border-radius) {
  @if $enable-rounded {
    @include ltr-rtl("border-top-right-radius", valid-radius($radius));
  }
}

@mixin border-bottom-end-radius($radius: $border-radius) {
  @if $enable-rounded {
    @include ltr-rtl("border-bottom-right-radius", valid-radius($radius));
  }
}

@mixin border-bottom-start-radius($radius: $border-radius) {
  @if $enable-rounded {
    @include ltr-rtl("border-bottom-left-radius", valid-radius($radius));
  }
}

Utilities API

Border utilities are declared in our utilities API in scss/_utilities.scss. Learn how to use the utilities API.

    "border": (
      property: border,
      values: (
        null: var(--cui-border-width) var(--cui-border-style) var(--cui-border-color),
        0: 0,
      ),
    ),
    "border-top": (
      property: border-top,
      values: (
        null: var(--cui-border-width) var(--cui-border-style) var(--cui-border-color),
        0: 0,
      )
    ),
    "border-end": (
      property: border-right,
      class: border-end,
      values: (
        null: var(--cui-border-width) var(--cui-border-style) var(--cui-border-color),
        0: 0,
      ),
      rtl: true
    ),
    "border-bottom": (
      property: border-bottom,
      values: (
        null: var(--cui-border-width) var(--cui-border-style) var(--cui-border-color),
        0: 0,
      )
    ),
    "border-start": (
      property: border-left,
      class: border-start,
      values: (
        null: var(--cui-border-width) var(--cui-border-style) var(--cui-border-color),
        0: 0,
      ),
      rtl: true
    ),
    "border-color": (
      property: border-color,
      class: border,
      local-vars: (
        "border-opacity": 1
      ),
      values: $utilities-border-colors
    ),
    "border-top-color": (
      property: border-top-color,
      class: border-top,
      values: map-merge($theme-colors, ("white": $white)),
      vars: true
    ),
    "border-end-color": (
      property: border-right-color,
      class: border-end,
      values: map-merge($theme-colors, ("white": $white)),
      vars: true,
      rtl: true
    ),
    "border-bottom-color": (
      property: border-bottom-color,
      class: border-bottom,
      values: map-merge($theme-colors, ("white": $white)),
      vars: true
    ),
    "border-start-color": (
      property: border-left-color,
      class: border-start,
      values: map-merge($theme-colors, ("white": $white)),
      vars: true,
      rtl: true
    ),
    "border-width": (
      css-var: true,
      css-variable-name: border-width,
      class: border,
      values: $border-widths
    ),
    "border-top-width": (
      property: border-top-width,
      class: border-top,
      values: $border-widths
    ),
    "border-end-width": (
      property: border-right-width,
      class: border-end,
      values: $border-widths,
      rtl: true
    ),
    "border-bottom-width": (
      property: border-bottom-width,
      class: border-bottom,
      values: $border-widths
    ),
    "border-start-width": (
      property: border-left-width,
      class: border-start,
      values: $border-widths,
      rtl: true
    ),
    "border-opacity": (
      css-var: true,
      class: border-opacity,
      values: (
        10: .1,
        25: .25,
        50: .5,
        75: .75,
        100: 1
      )
    ),
    
    "rounded": (
      property: border-radius,
      class: rounded,
      values: (
        null: var(--cui-border-radius),
        0: 0,
        1: var(--cui-border-radius-sm),
        2: var(--cui-border-radius),
        3: var(--cui-border-radius-lg),
        4: var(--cui-border-radius-xl),
        5: var(--cui-border-radius-2xl),
        circle: 50%,
        pill: var(--cui-border-radius-pill)
      )
    ),
    "rounded-top": (
      property: border-top-left-radius border-top-right-radius,
      class: rounded-top,
      values: (null: var(--cui-border-radius))
    ),
    "rounded-end": (
      property: border-top-right-radius border-bottom-right-radius,
      class: rounded-end,
      values: (null: var(--cui-border-radius)),
      rtl: true
    ),
    "rounded-bottom": (
      property: border-bottom-right-radius border-bottom-left-radius,
      class: rounded-bottom,
      values: (null: var(--cui-border-radius))
    ),
    "rounded-start": (
      property: border-bottom-left-radius border-top-left-radius,
      class: rounded-start,
      values: (null: var(--cui-border-radius)),
      rtl: true
    ),