Position

Shorthand utilities for the CSS position property, edge placement, and transform-based centering.

@layer utilities

Position values

Position utilities set the CSS position property directly. Responsive variants are not included.

<div class="position-static">...</div>
<div class="position-relative">...</div>
<div class="position-absolute">...</div>
<div class="position-fixed">...</div>
<div class="position-sticky">...</div>

Arrange elements

Edge placement utilities set top, start, bottom, and end CSS properties on positioned elements. The class format is {property}-{position}.

Where property is one of:

top - for the vertical top position
start - for the horizontal left position (in LTR)
bottom - for the vertical bottom position
end - for the horizontal right position (in LTR)

Where position is one of:

0 - for 0 edge position
50 - for 50% edge position
100 - for 100% edge position

Additional position values can be added by adding entries to the $position-values Sass map.

<div class="position-relative">
  <div class="position-absolute top-0 start-0"></div>
  <div class="position-absolute top-0 end-0"></div>
  <div class="position-absolute top-50 start-50"></div>
  <div class="position-absolute bottom-50 end-50"></div>
  <div class="position-absolute bottom-0 start-0"></div>
  <div class="position-absolute bottom-0 end-0"></div>
</div>

Center elements

.translate-middle applies translateX(-50%) translateY(-50%), centering an absolutely positioned element relative to its edge placement values. Combined with top-50 start-50, this achieves true absolute centering.

<div class="position-relative">
  <div class="position-absolute top-0 start-0 translate-middle"></div>
  <div class="position-absolute top-0 start-50 translate-middle"></div>
  <div class="position-absolute top-0 start-100 translate-middle"></div>
  <div class="position-absolute top-50 start-0 translate-middle"></div>
  <div class="position-absolute top-50 start-50 translate-middle"></div>
  <div class="position-absolute top-50 start-100 translate-middle"></div>
  <div class="position-absolute top-100 start-0 translate-middle"></div>
  <div class="position-absolute top-100 start-50 translate-middle"></div>
  <div class="position-absolute top-100 start-100 translate-middle"></div>
</div>

.translate-middle-x restricts the transform to the horizontal axis; .translate-middle-y restricts it to the vertical axis.

<div class="position-relative">
  <div class="position-absolute top-0 start-0"></div>
  <div class="position-absolute top-0 start-50 translate-middle-x"></div>
  <div class="position-absolute top-0 end-0"></div>
  <div class="position-absolute top-50 start-0 translate-middle-y"></div>
  <div class="position-absolute top-50 start-50 translate-middle"></div>
  <div class="position-absolute top-50 end-0 translate-middle-y"></div>
  <div class="position-absolute bottom-0 start-0"></div>
  <div class="position-absolute bottom-0 start-50 translate-middle-x"></div>
  <div class="position-absolute bottom-0 end-0"></div>
</div>

Examples

Practical combinations using position, translate, and badge utilities:

Marker

<button type="button" class="button primary position-relative">
  Mails <span class="position-absolute top-0 start-100 translate-middle badge rounded-full bg-contrast fg-secondary">+99 <span class="visually-hidden">unread messages</span></span>
</button>

<div class="position-relative py-xsmall px-large bg-inverse fg-inverse border rounded-full">
  Marker <svg width="1em" height="1em" viewBox="0 0 16 16" class="position-absolute top-100 start-50 translate-middle mt-2xsmall" fill="var(--cx-bg-inverse)" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"><path d="M7.247 11.14L2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z"/></svg>
</div>

<button type="button" class="button primary position-relative">
  Alerts <span class="position-absolute top-0 start-100 translate-middle badge border border-light rounded-full bg-danger p-xsmall"><span class="visually-hidden">unread messages</span></span>
</button>

The $position-values Sass map controls available position values.

<div class="position-relative m-large">
  <div class="progress" role="progressbar" aria-label="Progress" aria-valuenow="50" aria-valuemin="0" aria-valuemax="100" style="height: 1px;">
    <div class="progress-bar" style="width: 50%"></div>
  </div>
  <button type="button" class="position-absolute top-0 start-0 translate-middle button small primary rounded-full" style="width: 2rem; height:2rem;">1</button>
  <button type="button" class="position-absolute top-0 start-50 translate-middle button small primary rounded-full" style="width: 2rem; height:2rem;">2</button>
  <button type="button" class="position-absolute top-0 start-100 translate-middle button small secondary rounded-full" style="width: 2rem; height:2rem;">3</button>
</div>

CSS

Position utilities are generated from Sass maps via the utilities API.

Reference

Class	Properties
`.fixed-top`	`position: fixed; inset: 0 0 auto; z-index: 1030;`
`.fixed-bottom`	`position: fixed; inset: auto 0 0; z-index: 1030;`
`.sticky-top`	`position: sticky; inset-block-start: 0; z-index: 1020;`
`.sticky-bottom`	`position: sticky; inset-block-end: 0; z-index: 1020;`
`.position-static`	`position: static;`
`.position-relative`	`position: relative;`
`.position-absolute`	`position: absolute;`
`.position-fixed`	`position: fixed;`
`.position-sticky`	`position: sticky;`
`.top-0`	`inset-block-start: 0;`
`.top-25`	`inset-block-start: 25%;`
`.top-50`	`inset-block-start: 50%;`
`.top-75`	`inset-block-start: 75%;`
`.top-100`	`inset-block-start: 100%;`
`.bottom-0`	`inset-block-end: 0;`
`.bottom-25`	`inset-block-end: 25%;`
`.bottom-50`	`inset-block-end: 50%;`
`.bottom-75`	`inset-block-end: 75%;`
`.bottom-100`	`inset-block-end: 100%;`
`.start-0`	`inset-inline-start: 0;`
`.start-25`	`inset-inline-start: 25%;`
`.start-50`	`inset-inline-start: 50%;`
`.start-75`	`inset-inline-start: 75%;`
`.start-100`	`inset-inline-start: 100%;`
`.end-0`	`inset-inline-end: 0;`
`.end-25`	`inset-inline-end: 25%;`
`.end-50`	`inset-inline-end: 50%;`
`.end-75`	`inset-inline-end: 75%;`
`.end-100`	`inset-inline-end: 100%;`
`.translate-middle`	`transform: translate(-50%, -50%);`
`.translate-middle-x`	`transform: translateX(-50%);`
`.translate-middle-y`	`transform: translateY(-50%);`

Sass maps

Position utilities are generated from Sass maps in scss/config/_defaults.scss.

$position-values: (
  0: 0,
  25: 25%,
  50: 50%,
  75: 75%,
  100: 100%
);

Utilities API

Position utilities are declared in scss/utilities/_position.scss using the utilities API.

"position": (
  property: position,
  values: static relative absolute fixed sticky
),
"top": (
  property: inset-block-start,
  class: top,
  values: $position-values
),
"bottom": (
  property: inset-block-end,
  class: bottom,
  values: $position-values
),
"start": (
  property: inset-inline-start,
  class: start,
  values: $position-values
),
"end": (
  property: inset-inline-end,
  class: end,
  values: $position-values
),
"translate-middle": (
  property: transform,
  class: translate-middle,
  values: (
    null: translate(-50%, -50%),
    x: translateX(-50%),
    y: translateY(-50%),
  )
),