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---
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layout: docs
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title: Spacing
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description: Bootstrap includes a wide range of shorthand responsive margin and padding utility classes to modify an element's appearance.
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group: utilities
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toc: true
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---
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## How it works
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Assign responsive-friendly `margin` or `padding` values to an element or a subset of its sides with shorthand classes. Includes support for individual properties, all properties, and vertical and horizontal properties. Classes are built from a default Sass map ranging from `.25rem` to `3rem`.
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## Notation
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Spacing utilities that apply to all breakpoints, from `xs` to `xl`, have no breakpoint abbreviation in them. This is because those classes are applied from `min-width: 0` and up, and thus are not bound by a media query. The remaining breakpoints, however, do include a breakpoint abbreviation.
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The classes are named using the format `{property}{sides}-{size}` for `xs` and `{property}{sides}-{breakpoint}-{size}` for `sm`, `md`, `lg`, and `xl`.
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Where *property* is one of:
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* `m` - for classes that set `margin`
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* `p` - for classes that set `padding`
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Where *sides* is one of:
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* `t` - for classes that set `margin-top` or `padding-top`
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* `b` - for classes that set `margin-bottom` or `padding-bottom`
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* `l` - for classes that set `margin-left` or `padding-left`
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* `r` - for classes that set `margin-right` or `padding-right`
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* `x` - for classes that set both `*-left` and `*-right`
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* `y` - for classes that set both `*-top` and `*-bottom`
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* blank - for classes that set a `margin` or `padding` on all 4 sides of the element
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Where *size* is one of:
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* `0` - for classes that eliminate the `margin` or `padding` by setting it to `0`
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* `1` - (by default) for classes that set the `margin` or `padding` to `$spacer * .25`
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* `2` - (by default) for classes that set the `margin` or `padding` to `$spacer * .5`
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* `3` - (by default) for classes that set the `margin` or `padding` to `$spacer`
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* `4` - (by default) for classes that set the `margin` or `padding` to `$spacer * 1.5`
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* `5` - (by default) for classes that set the `margin` or `padding` to `$spacer * 3`
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* `auto` - for classes that set the `margin` to auto
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(You can add more sizes by adding entries to the `$spacers` Sass map variable.)
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## Examples
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Here are some representative examples of these classes:
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```scss
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.mt-0 {
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  margin-top: 0 !important;
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}
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.ml-1 {
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  margin-left: ($spacer * .25) !important;
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}
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.px-2 {
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  padding-left: ($spacer * .5) !important;
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  padding-right: ($spacer * .5) !important;
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}
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.p-3 {
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  padding: $spacer !important;
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}
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```
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### Horizontal centering
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Additionally, Bootstrap also includes an `.mx-auto` class for horizontally centering fixed-width block level content—that is, content that has `display: block` and a `width` set—by setting the horizontal margins to `auto`.
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<div class="bd-example">
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  <div class="mx-auto" style="width: 200px; background-color: rgba(86,61,124,.15);">
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    Centered element
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  </div>
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</div>
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```html
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<div class="mx-auto" style="width: 200px;">
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  Centered element
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</div>
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```
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### Negative margin
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In CSS, `margin` properties can utilize negative values (`padding` cannot). As of 4.2, we've added negative margin utilities for every non-zero integer size listed above (e.g., `1`, `2`, `3`, `4`, `5`). These utilities are ideal for customizing grid column gutters across breakpoints.
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The syntax is nearly the same as the default, positive margin utilities, but with the addition of `n` before the requested size. Here's an example class that's the opposite of `.mt-1`:
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```scss
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.mt-n1 {
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  margin-top: -0.25rem !important;
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}
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```
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Here's an example of customizing the Bootstrap grid at the medium (`md`) breakpoint and above. We've increased the `.col` padding with `.px-md-5` and then counteracted that with `.mx-md-n5` on the parent `.row`.
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{{< example >}}
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<div class="row mx-md-n5">
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  <div class="col px-md-5"><div class="p-3 border bg-light">Custom column padding</div></div>
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  <div class="col px-md-5"><div class="p-3 border bg-light">Custom column padding</div></div>
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</div>
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{{< /example >}}