$count: 12

$box-width: 7 / 120 * 100%
$box-margin: 1 / 80 * 100%

$full-width: 25 / 3 / 100 * 100%
$full-margin: 0

.row
    @include clearfix()

.box
    float: left
    margin-left: $box-margin
    margin-right: $box-margin
    @include bottom-margin()

    @media (max-width: $breakpoint-width)
        width: 100% !important
        margin-left: auto
        margin-right: auto
        display: block
        float: none

.full
    float: left
    @include bottom-margin()

    @media (max-width: $breakpoint-width)
        width: 100% !important
        display: block
        float: none

@for $i from 1 through $count
    .box.col-#{$i}
        width: $box-width * $i + $box-margin * 2 * ($i - 1)

    .full.col-#{$i}
        width: $full-width * $i + $full-margin * 2 * ($i - 1)