@mixin span($start, $span) {
  grid-column: $start / span $span;
}

@mixin column-span($start, $span) {
  @include span($start, $span);
}

// ----

@mixin vertical-span($start, $span) {
  grid-row: $start / span $span;
}

@mixin row-span($start, $span) {
  @include vertical-span($start, $span);
}

@mixin span($span, $start: false) {
  @if $start {
    grid-column: $start / span $span;
  }
  @else {
    grid-column: span $span;
  }
}

@mixin column-span($span, $start: false) {
  @include span($span, $start);
}

// ----

@mixin vertical-span($span, $start: false) {
  @if $start {
    grid-row: $start / span $span;
  }
  @else {
    grid-row: span $span;
  }
}

@mixin row-span($span, $start: false) {
  @include vertical-span($span, $start);
}

Swap $span and $start in span mixins
:boom: Swap $span and $start in span mixins

Align with Singularity, number to span first, from where second
