twbs--bootstrap/docs/utilities/spacing.md

layout	title	group
docs	Spacing	utilities

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.

Contents

• Will be replaced with the ToC, excluding the "Contents" header {:toc}

Notation

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.

The classes are named using the format {property}{sides}-{size} for xs and {property}{sides}-{breakpoint}-{size} for sm, md, lg, and xl.

Where property is one of:

• m - for classes that set margin
• p - for classes that set padding

Where sides is one of:

• t - for classes that set margin-top or padding-top
• b - for classes that set margin-bottom or padding-bottom
• l - for classes that set margin-left or padding-left
• r - for classes that set margin-right or padding-right
• x - for classes that set both *-left and *-right
• y - for classes that set both *-top and *-bottom
• blank - for classes that set a margin or padding on all 4 sides of the element

Where size is one of:

• 0 - for classes that eliminate the margin or padding by setting it to 0
• 1 - (by default) for classes that set the margin or padding to $spacer-x * .25 or $spacer-y * .25
• 2 - (by default) for classes that set the margin or padding to $spacer-x * .5 or $spacer-y * .5
• 3 - (by default) for classes that set the margin or padding to $spacer-x or $spacer-y
• 4 - (by default) for classes that set the margin or padding to $spacer-x * 1.5 or $spacer-y * 1.5
• 5 - (by default) for classes that set the margin or padding to $spacer-x * 3 or $spacer-y * 3

(You can add more sizes by adding entries to the $spacers Sass map variable.)

Examples

Here are some representative examples of these classes:

{% highlight scss %} .mt-0 { margin-top: 0 !important; }

.ml-1 { margin-left: ($spacer-x * .25) !important; }

.px-2 { padding-left: ($spacer-x * .5) !important; padding-right: ($spacer-x * .5) !important; }

.p-3 { padding: $spacer-y $spacer-x !important; } {% endhighlight %}

Horizontal centering

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.

Centered element

{% highlight html %}

Centered element

{% endhighlight %}