css/docs/content/utilities/margin.md

title	path	status	source	bundle
Margin	utilities/margin	Stable	https://github.com/primer/css/blob/main/src/utilities/margin.scss	utilities

Margin utilities are based on a global spacing scale which helps keep horizontal and vertical spacing consistent. These utilities help us reduce the amount of custom CSS that share the same properties, and allows to achieve many different page layouts using the same styles.

Naming convention

Since margin utilities have many variations and will be used in many places, we use a shorthand naming convention to help keep class names succinct.

Shorthand	Description
m	margin
t	top
r	right
b	bottom
l	left
x	horizontal, left & right
y	vertical, top & bottom
0	0
1	4px
2	8px
3	16px
4	24px
5	32px
6	40px
7	48px
8	64px
9	80px
10	96px
11	112px
12	128px

Uniform margins

Use uniform spacing utilities to apply equal margin to all sides of an element. These utilities can change or override default margins, and can be used with a spacing scale from 0-6.

<div class="d-flex flex-items-baseline flex-justify-around">
  <div class="color-bg-warning"><div class="m-0 p-1 color-bg-secondary">.m-0</div></div>
  <div class="color-bg-warning"><div class="m-1 p-1 color-bg-secondary">.m-1</div></div>
  <div class="color-bg-warning"><div class="m-2 p-1 color-bg-secondary">.m-2</div></div>
  <div class="color-bg-warning"><div class="m-3 p-1 color-bg-secondary">.m-3</div></div>
  <div class="color-bg-warning"><div class="m-4 p-1 color-bg-secondary">.m-4</div></div>
  <div class="color-bg-warning"><div class="m-5 p-1 color-bg-secondary">.m-5</div></div>
  <div class="color-bg-warning"><div class="m-6 p-1 color-bg-secondary">.m-6</div></div>
</div>

Directional margins

Use directional utilities to apply margin to an individual side, or the X and Y axis of an element. Directional utilities can change or override default margins, and can be used with a spacing scale of 0-6.

<div class="d-flex flex-items-baseline flex-justify-around">
  <div class="color-bg-warning"><div class="mt-3 p-1 color-bg-secondary">.mt-3</div></div>
  <div class="color-bg-warning"><div class="mr-3 p-1 color-bg-secondary">.mr-3</div></div>
  <div class="color-bg-warning"><div class="mb-3 p-1 color-bg-secondary">.mb-3</div></div>
  <div class="color-bg-warning"><div class="ml-3 p-1 color-bg-secondary">.ml-3</div></div>
  <div class="color-bg-warning"><div class="mx-3 p-1 color-bg-secondary">.mx-3</div></div>
  <div class="color-bg-warning"><div class="my-3 p-1 color-bg-secondary">.my-3</div></div>
</div>

Extended vertical margins

The extended scale starts from spacer 7 up to 12. Note: Only the y-axis (mt, mb and my) and its responsive variants are supported.

<div class="color-bg-warning d-inline-block"><div class="mt-7  p-1 color-bg-secondary">.mb-7</div></div>
<div class="color-bg-warning d-inline-block"><div class="mt-8  p-1 color-bg-secondary">.mb-8</div></div>
<div class="color-bg-warning d-inline-block"><div class="mt-9  p-1 color-bg-secondary">.mb-9</div></div>
<div class="color-bg-warning d-inline-block"><div class="mt-10 p-1 color-bg-secondary">.mb-10</div></div>
<div class="color-bg-warning d-inline-block"><div class="mt-11 p-1 color-bg-secondary">.mb-11</div></div>
<div class="color-bg-warning d-inline-block"><div class="mt-12 p-1 color-bg-secondary">.mb-12</div></div>

Center elements

Use mx-autoto center block elements with a set width.

<div class="color-bg-warning">
  <div class="mx-auto color-bg-secondary text-center" style="max-width: 500px;">.mx-auto</div>
</div>

We also provide directional margin auto. mt-auto, mr-auto, mb-auto, ml-auto

<div class="d-flex border mb-4">
  <div style="height:100px;"></div>
  <div class="border mt-auto">`mt-auto` will push this box to the bottom.</div>
  <div class="border mb-auto">`mb-auto` will push this box to the top.</div>
</div>
<div class="d-flex flex-column border">
  <div class="border ml-auto">`ml-auto` will push this box to the right.</div>
  <div class="border mr-auto">`mr-auto` will push this box to the left.</div>
</div>

Reset margins

Reset margins built into typography elements or other components with m-0, mt-0, mr-0, mb-0, ml-0, mx-0, and my-0.

<div class="color-bg-warning border">
  <p class="mb-0 color-bg-secondary p-1">No bottom margin on this paragraph.</p>
</div>

Responsive margins

All margin utilities can be adjusted per breakpoint using the following formula: m[direction]-[breakpoint]-[spacer]. Each responsive style is applied to the specified breakpoint and up.

<div class="color-bg-warning d-inline-block">
  <div class="mx-sm-2 mx-md-4 color-bg-secondary p-1">
    .mx-sm-2 .mx-md-4
  </div>
</div>

Negative margins

You can add negative margins to the top, right, bottom, or left of an item by adding a negative margin utility. The formula for this is: m[direction]-n[spacer], where spacer runs from 1 to 6. This also works responsively, with the following formula: m[direction]-[breakpoint]-n[spacer].

<div class="d-flex flex-justify-center">
  <div class="color-bg-warning">
    <div class="m-3 ml-n4 ml-md-n6 border-left color-border-danger color-bg-secondary p-2">
      .m-3 .ml-n4 .ml-md-n6
    </div>
  </div>
</div>

Extended negative margins

You can use the extended spacing scale for top and bottom margins, ranging from 1 to 12.

<div class="d-flex flex-justify-center">
  <div class="py-6 px-3 color-bg-warning">
    <div class="mt-n8 border-left color-border-danger color-bg-tertiary p-2">
      .mt-n8
    </div>
  </div>
</div>