// ==================================================
// Columns
// ==================================================
@mixin columns($_columns: 1, $_position: default, $_max-width: false) {
  @if $_max-width == max or $_max-width == true {
    $_column-width: column-width($_columns, false);

    width: 100%;
    max-width: $_column-width;
  }
  @else { // $_max-width == default
    width: column-width($_columns);
  }

  @if $_position == center {
    margin-left: auto;
    margin-right: auto;
  }
  @else {
    $_float: left;
    $_margin: right;

    @if $grid-rtl == true {
      $_float: right;
      $_margin: left;
    }

    @if $_position != last and $grid-collapse == false {
      margin-#{$_margin}: gutter-width();
    }

    @if $grid-flexbox == false {
      float: $_float;
    }
  }
}

// ==================================================
// Columns
// ==================================================
@mixin columns($_columns: 1, $_position: default, $_max-width: false) {
  @if $_max-width == max or $_max-width == true {
    $_column-width: column-width($_columns, false);

    @if $grid-flexbox == true {
      width: 100%;
    }
    max-width: $_column-width;
  }
  @else { // $_max-width == default
    width: column-width($_columns);
  }

  @if $_position == center {
    margin-left: auto;
    margin-right: auto;
  }
  @else {
    $_float: left;
    $_margin: right;

    @if $grid-rtl == true {
      $_float: right;
      $_margin: left;
    }

    @if $_position != last and $grid-collapse == false {
      margin-#{$_margin}: gutter-width();
    }

    @if $grid-flexbox == false {
      float: $_float;
    }
  }
}

Adjust column mixin to only include width: 100%; when flexbox is enabled.
Adjust column mixin to only include width: 100%; when flexbox is enabled.
