$spaceAmounts: (0, 2, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 48, 60, 80); // Adjust this to include the pixel amounts you need.
$sides: (top, bottom, left, right); // Leave this variable alone

@each $space in $spaceAmounts {

  .m-#{$space} {
    margin: #{$space}px !important;
  }

  .p-#{$space} {
    padding: #{$space}px !important;
  }

  .m-tb-#{$space} {
    margin-top: #{$space}px !important;
    margin-bottom: #{$space}px !important;
  }

  .m-rl-#{$space} {
    margin-right: #{$space}px !important;
    margin-left: #{$space}px !important;
  }

  .p-tb-#{$space} {
    padding-top: #{$space}px !important;
    padding-bottom: #{$space}px !important;
  }

  .p-rl-#{$space} {
    padding-right: #{$space}px !important;
    padding-left: #{$space}px !important;
  }

  .l-s-#{$space} {
    letter-spacing: #{$space}px !important;
    margin-right: -#{$space}px;
  }

  .l-h-#{$space} {
    line-height: #{$space}px !important;
  }

  @each $side in $sides {
    .m-#{str-slice($side, 0, 1)}-#{$space} {
      margin-#{$side}: #{$space}px !important;
    }

    .p-#{str-slice($side, 0, 1)}-#{$space} {
      padding-#{$side}: #{$space}px !important;
    }
  }
}