.grid-section {
  $gridItemSpace: 15%;

  @mixin gridCol($numOfCols, $flexBasis) {
    .#{grid-col- + $numOfCols} {
      @extend %grid-col-base;
      flex-basis:  $flexBasis;
      &:not(.last-col-in-row):after {
        flex-basis: $gridItemSpace / $numOfCols;
        content: ' ';
      }
    }
  }

  @mixin gridColWithLastColumn($numOfCols, $flexBasis, $flexBasisLast) {
    .#{grid-col- + $numOfCols} {
      @extend %grid-col-base;
      &:not(.last-col-in-row) {
        flex-basis:  $flexBasis;
        margin-right: 5%;
      }
      &.last-col-in-row {
        flex-basis:  $flexBasisLast;
      }
    }
  }

  &:not(:last-of-type) {
    padding-bottom: 30px;
  }

  .grid-items {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
  }

  %grid-col-base {
    flex-shrink: 0;
    display: flex;
  }

  .grid-item {
    flex: 1;
    display: flex;
    flex-direction: column;
  }

  .grid-item-stretch {
    @extend .grid-item;
    & *:last-child {
      flex: 1;
      display: flex;
      flex-direction: column;
    }
  }

  &.has-last-col-set {
    @include gridColWithLastColumn(1, 21%, 22%);
    @include gridColWithLastColumn(2, 47%, 48%);
    @include gridColWithLastColumn(3, 73%, 74%);
    @include gridColWithLastColumn(4, 100%, 100%);
  }

  &:not(.has-last-col-set) {
    @include gridCol(1, 25%);
    @include gridCol(2, 50%);
    @include gridCol(3, 75%);
    @include gridCol(4, 100%);
  }
}