Bootstrap includes a wide range of shorthand responsive margin and padding utility classes to modify an element's appearance.
How it works
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.
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 * .25
-
2 - (by default) for classes that set the
margin or
padding to
$spacer * .5
-
3 - (by default) for classes that set the
margin or
padding to
$spacer
-
4 - (by default) for classes that set the
margin or
padding to
$spacer * 1.5
-
5 - (by default) for classes that set the
margin or
padding to
$spacer * 3
-
auto - for classes that set the
margin to auto
Examples
Here are some representative examples of these classes:
.mt-0 {
margin-top: 0 !important;
}
.ml-1 {
margin-left: ($spacer * .25) !important;
}
.px-2 {
padding-left: ($spacer * .5) !important;
padding-right: ($spacer * .5) !important;
}
.p-3 {
padding: $spacer !important;
}
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.
<div class="mx-auto" style="width: 200px; background-color: rgba(86,61,124,.15);">
Centered element
</div>