Flexbox grid plugin with old iPhone fallback

_fallback.scss

/**
 * _fallback.scss
 *
 * Fallback grid for flexboxgrid.scss
 * Fixes iPhone 4 and 5 issues.
 */

.row {
  display: block;
  font-family: empty;
}
.col-xs,
.col-xs-1,
.col-xs-2,
.col-xs-3,
.col-xs-4,
.col-xs-5,
.col-xs-6,
.col-xs-7,
.col-xs-8,
.col-xs-9,
.col-xs-10,
.col-xs-11,
.col-xs-12 {
  display: inline-block;
  font-family: $body-font;
}
.col-xs {
  width: 100%;
}
@for $i from 1 through 12 {
  .col-xs-#{$i} {
    width: percentage($i/12);
  }
}

.start-xs {
  text-align: left;
}
.center-xs {
  text-align: center;
}
.end-xs {
  text-align: right;
}
.top-xs {
  vertical-align: top;
}
.middle-xs {
  vertical-align: middle;
}
.bottom-xs {
  vertical-align: bottom;
}

@media only screen and (min-width: $break-sm) {
  .col-sm,
  .col-sm-1,
  .col-sm-2,
  .col-sm-3,
  .col-sm-4,
  .col-sm-5,
  .col-sm-6,
  .col-sm-7,
  .col-sm-8,
  .col-sm-9,
  .col-sm-10,
  .col-sm-11,
  .col-sm-12 {
    display: inline-block;
    font-family: $body-font;
  }
  .col-sm {
    width: 100%;
  }
  @for $i from 1 through 12 {
    .col-sm-#{$i} {
      width: percentage($i/12);
    }
  }

  .start-sm {
    text-align: left;
  }
  .center-sm {
    text-align: center;
  }
  .end-sm {
    text-align: right;
  }
  .top-sm {
    vertical-align: top;
  }
  .middle-sm {
    vertical-align: middle;
  }
  .bottom-sm {
    vertical-align: bottom;
  }
}

@media only screen and (min-width: $break-md) {
  .col-md,
  .col-md-1,
  .col-md-2,
  .col-md-3,
  .col-md-4,
  .col-md-5,
  .col-md-6,
  .col-md-7,
  .col-md-8,
  .col-md-9,
  .col-md-10,
  .col-md-11,
  .col-md-12 {
    display: inline-block;
    font-family: $body-font;
  }
  .col-md {
    width: 100%;
  }
  @for $i from 1 through 12 {
    .col-md-#{$i} {
      width: percentage($i/12);
    }
  }

  .start-md {
    text-align: left;
  }
  .center-md {
    text-align: center;
  }
  .end-md {
    text-align: right;
  }
  .top-md {
    vertical-align: top;
  }
  .middle-md {
    vertical-align: middle;
  }
  .bottom-md {
    vertical-align: bottom;
  }
}

@media only screen and (min-width: $break-lg) {
  .col-lg,
  .col-lg-1,
  .col-lg-2,
  .col-lg-3,
  .col-lg-4,
  .col-lg-5,
  .col-lg-6,
  .col-lg-7,
  .col-lg-8,
  .col-lg-9,
  .col-lg-10,
  .col-lg-11,
  .col-lg-12 {
    display: inline-block;
    font-family: $body-font;
  }
  .col-lg {
    width: 100%;
  }
  @for $i from 1 through 12 {
    .col-lg-#{$i} {
      width: percentage($i/12);
    }
  }

  .start-lg {
    text-align: left;
  }
  .center-lg {
    text-align: center;
  }
  .end-lg {
    text-align: right;
  }
  .top-lg {
    vertical-align: top;
  }
  .middle-lg {
    vertical-align: middle;
  }
  .bottom-lg {
    vertical-align: bottom;
  }
}

flexboxgrid.scss

/**
 * flexboxgrid.scss
 */

/*
Variables
 */
$gutter-width: 1.25rem !default;

// set up container/rows
.container-fluid,
.container {
  margin-right: auto;
  margin-left: auto;
  padding-right: $gutter-width;
  padding-left: $gutter-width;
}
.row {
  box-sizing: border-box;
  display: flex;
  flex: 0 1 auto;
  flex-direction: row;
  flex-wrap: wrap;
  margin-right: -$gutter-width;
  margin-left: -$gutter-width;
}
.row.reverse {
  flex-direction: row-reverse;
}
.col.reverse {
  flex-direction: column-reverse;
}

.col-xs,
.col-xs-1,
.col-xs-2,
.col-xs-3,
.col-xs-4,
.col-xs-5,
.col-xs-6,
.col-xs-7,
.col-xs-8,
.col-xs-9,
.col-xs-10,
.col-xs-11,
.col-xs-12 {
  box-sizing: border-box;
  flex: 0 0 auto;
  padding-right: $gutter-width;
  padding-left: $gutter-width;
}
.col-xs {
  flex-grow: 1;
  flex-basis: 0;
  max-width: 100%;
}

@for $i from 1 through 12 {
  .col-xs-#{$i} {
    flex-basis: percentage($i/12);
    max-width: percentage($i/12);
  }
  .col-xs-offset-#{$i} {
    margin-left: percentage($i/12);
  }
}

.start-xs {
  justify-content: flex-start;
  text-align: start;
}
.center-xs {
  justify-content: center;
  text-align: center;
}
.end-xs {
  justify-content: flex-end;
  text-align: end;
}
.top-xs {
  align-items: flex-start;
}
.middle-xs {
  align-items: center;
}
.bottom-xs {
  align-items: flex-end;
}
.around-xs {
  justify-content: space-around;
}
.between-xs {
  justify-content: space-between;
}
.first-xs {
  order: -1;
}
.last-xs {
  order: 1;
}

@media only screen and (min-width: $break-sm) {
  .container {
    width: $break-sm - (2 * $gutter-width);
  }
  .col-sm,
  .col-sm-1,
  .col-sm-2,
  .col-sm-3,
  .col-sm-4,
  .col-sm-5,
  .col-sm-6,
  .col-sm-7,
  .col-sm-8,
  .col-sm-9,
  .col-sm-10,
  .col-sm-11,
  .col-sm-12 {
    box-sizing: border-box;
    flex: 0 0 auto;
    padding-right: $gutter-width;
    padding-left: $gutter-width;
  }
  .col-sm {
    flex-grow: 1;
    flex-basis: 0;
    max-width: 100%;
  }

  @for $i from 1 through 12 {
    .col-sm-#{$i} {
      flex-basis: percentage($i/12);
      max-width: percentage($i/12);
    }
    .col-sm-offset-#{$i} {
      margin-left: percentage($i/12);
    }
  }

  .start-sm {
    justify-content: flex-start;
    text-align: start;
  }
  .center-sm {
    justify-content: center;
    text-align: center;
  }
  .end-sm {
    justify-content: flex-end;
    text-align: end;
  }
  .top-sm {
    align-items: flex-start;
  }
  .middle-sm {
    align-items: center;
  }
  .bottom-sm {
    align-items: flex-end;
  }
  .around-sm {
    justify-content: space-around;
  }
  .between-sm {
    justify-content: space-between;
  }
  .first-sm {
    order: -1;
  }
  .last-sm {
    order: 1;
  }
}

@media only screen and (min-width: $break-md) {
  .container {
    width: $break-md - (2 * $gutter-width);
  }
  .col-md,
  .col-md-1,
  .col-md-2,
  .col-md-3,
  .col-md-4,
  .col-md-5,
  .col-md-6,
  .col-md-7,
  .col-md-8,
  .col-md-9,
  .col-md-10,
  .col-md-11,
  .col-md-12 {
    box-sizing: border-box;
    flex: 0 0 auto;
    padding-right: $gutter-width;
    padding-left: $gutter-width;
  }
  .col-md {
    flex-grow: 1;
    flex-basis: 0;
    max-width: 100%;
  }

  @for $i from 1 through 12 {
    .col-md-#{$i} {
      flex-basis: percentage($i/12);
      max-width: percentage($i/12);
    }
    .col-md-offset-#{$i} {
      margin-left: percentage($i/12);
    }
  }

  .start-md {
    justify-content: flex-start;
    text-align: start;
  }
  .center-md {
    justify-content: center;
    text-align: center;
  }
  .end-md {
    justify-content: flex-end;
    text-align: end;
  }
  .top-md {
    align-items: flex-start;
  }
  .middle-md {
    align-items: center;
  }
  .bottom-md {
    align-items: flex-end;
  }
  .around-md {
    justify-content: space-around;
  }
  .between-md {
    justify-content: space-between;
  }
  .first-md {
    order: -1;
  }
  .last-md {
    order: 1;
  }
}

@media only screen and (min-width: $break-lg) {
  .container {
    width: $break-lg - (2 * $gutter-width);
  }
  .col-lg,
  .col-lg-1,
  .col-lg-2,
  .col-lg-3,
  .col-lg-4,
  .col-lg-5,
  .col-lg-6,
  .col-lg-7,
  .col-lg-8,
  .col-lg-9,
  .col-lg-10,
  .col-lg-11,
  .col-lg-12 {
    box-sizing: border-box;
    flex: 0 0 auto;
    padding-right: $gutter-width;
    padding-left: $gutter-width;
  }
  .col-lg {
    flex-grow: 1;
    flex-basis: 0;
    max-width: 100%;
  }

  @for $i from 1 through 12 {
    .col-lg-#{$i} {
      flex-basis: percentage($i/12);
      max-width: percentage($i/12);
    }
    .col-lg-offset-#{$i} {
      margin-left: percentage($i/12);
    }
  }

  .start-lg {
    justify-content: flex-start;
    text-align: start;
  }
  .center-lg {
    justify-content: center;
    text-align: center;
  }
  .end-lg {
    justify-content: flex-end;
    text-align: end;
  }
  .top-lg {
    align-items: flex-start;
  }
  .middle-lg {
    align-items: center;
  }
  .bottom-lg {
    align-items: flex-end;
  }
  .around-lg {
    justify-content: space-around;
  }
  .between-lg {
    justify-content: space-between;
  }
  .first-lg {
    order: -1;
  }
  .last-lg {
    order: 1;
  }
}

/*
Fallback
 */
// targets iPhone 4 and 5 (portrait and landscape)
@media only screen and (min-device-width: 320px) and (max-device-width: 480px) and (-webkit-device-pixel-ratio: 2) and (device-aspect-ratio: 2/3), only screen and (min-device-width: 320px) and (max-device-width: 568px) and (-webkit-device-pixel-ratio: 2) and (device-aspect-ratio: 40/71) {
  @import "fallback";
}