Bootstrap-Notations
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

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

 

Example for understanding concept not for production.

 

Ex.

.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

.mx-auto use to show content div on center by horizontal.

​

Ex.

<div class="mx-auto" style="width: 200px;">

  Centered element

</div>

 

Negative margin

In this use n before the requested size(e.g. 1,2,3,4,5)

​

Ex.

<div class="row mx-md-n5">

  <div class="col px-md-5"><div class="p-3 border bg-light">Custom column padding</div></div>

  <div class="col px-md-5"><div class="p-3 border bg-light">Custom column padding</div></div>

</div>

 

Display two div into left and right and space   at breakpoint between these two div.