webpack-bootstrap-ui-kit/src/scss/elements/grid.scss

.elemental-area {
  display: flex;
  flex-direction: column;
  --bs-gutter-x: 0.75rem;
  --bs-gutter-y: 0.5rem;

  > .element {
    &:first-child {
      margin-top: 0;
    }

    &:last-child {
      margin-bottom: 0;
    }
  }
}

.element {
  position: relative;

  margin-top: $element-spacer-y;
  margin-bottom: $element-spacer-y;
  padding-top: $element-spacer-y;
  padding-bottom: $element-spacer-y;

  // Sidebar-like elements
  &.secondary {
    padding-top: ($element-reduced-spacer-y);
    padding-bottom: ($element-reduced-spacer-y);
  }
}

// sub-elements
.element {
  .elemental-area {
    .element {
      .container,
      .container-fluid {
        padding: 0;
        width: auto;
      }
    }
  }
}