Spacing
Bootstrap 5 Spacing utilities
MDB 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.
    
      Note: If you want to add margin to the left side you must use the class
      ms-* (margin start) instead of ml-* (margin left).
    
      Likewise for the margin on the right: you have to use the class me-* (margin end) instead
      of mr-* (margin right).
    
Below is an example using classes for the right margin with a visual representation of their sizes. The same sizes apply to all directions (left, right, top, bottom) and for both margins and padding.
| Class name | Size | Visual representation | 
|---|---|---|
| .me-1 | 0.25rem | |
| .me-2 | 0.5rem | |
| .me-3 | 1rem | |
| .me-4 | 1.5rem | |
| .me-5 | 3rem | 
Notation
      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 setmargin-toporpadding-top
- 
        b- for classes that setmargin-bottomorpadding-bottom
- 
        s- (start) for classes that setmargin-leftorpadding-left
- 
        e- (end) for classes that setmargin-rightorpadding-right
- 
        x- for classes that set both*-leftand*-right
- 
        y- for classes that set both*-topand*-bottom
- 
        blank - for classes that set a marginorpaddingon all 4 sides of the element
Where size is one of:
- 
        0- for classes that eliminate themarginorpaddingby setting it to0
- 
        1- (by default) for classes that set themarginorpaddingto$spacer * .25
- 
        2- (by default) for classes that set themarginorpaddingto$spacer * .5
- 
        3- (by default) for classes that set themarginorpaddingto$spacer
- 
        4- (by default) for classes that set themarginorpaddingto$spacer * 1.5
- 
        5- (by default) for classes that set themarginorpaddingto$spacer * 3
- auto- for classes that set the- marginto auto
      (You can add more sizes by adding entries to the $spacers Sass map variable.)
    
Examples
Here are some representative examples of these classes:
        
            
          .mt-0 {
            margin-top: 0 !important;
          }
          .ms-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">Centered element</div>
          
        
    
Negative margin
        In CSS, margin properties can utilize negative values (padding
        cannot). These negative margins are disabled by default, but can be enabled
        in Sass by setting $enable-negative-margins: true.
      
        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:
      
        
            
            .mt-n1 {
              margin-top: -0.25rem !important;
            }
            
        
    
Gap
        When using display: grid, you can make use of gap utilities on the
        parent grid container. This can save on having to add margin utilities to individual grid
        items (children of a display: grid container). Gap utilities are responsive by
        default, and are generated via our utilities API, based on the $spacers Sass
        map.
      
        
            
            <div class="d-grid gap-3">
              <div class="p-2 bg-body-tertiary border">Grid item 1</div>
              <div class="p-2 bg-body-tertiary border">Grid item 2</div>
              <div class="p-2 bg-body-tertiary border">Grid item 3</div>
            </div>
          
        
    
        Support includes responsive options for all of Bootstrap’s grid breakpoints, as well as six
        sizes from the $spacers map (0–5). There is no
        .gap-auto utility class as it’s effectively the same as .gap-0.
      
Extra scale for the bottom margin
By default, MDB provides an additional scale for the bottom margin.
This allows for easier positioning of larger elements (such as sections or design blocks) in relation to each other and more comfortable creating a layout with a consistent composition.
Note:The standard scale with classes from .mb-1 to .mb-5 works as normal.
      The classes below are additional and only apply to the bottom margin.
.mb-6
        3.5rem
        .mb-7
        4rem
        .mb-8
        5rem
        .mb-9
        6rem
        .mb-10
        8rem
        .mb-11
        10rem
        .mb-12
        12rem
        .mb-13
        14rem
        .mb-14
        16rem
        