Bootstrap margin & padding (spacing)
Spacing utilities that apply to all breakpoints, from xs to xxl, 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, xl, and xxl.
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
- s - (start) for classes that set margin-left or padding-left in LTR, margin-right or padding-right in RTL
- e - (end) for classes that set margin-right or padding-right in LTR, margin-left or padding-left in RTL
- 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.)
https://getbootstrap.com/docs/5.3/utilities/spacing/#notation