.u-border {
    directions  = top bottom left right;
    colors      = 'blue' 'green' 'pink' 'purple' 'red' 'white' 'yellow';

    border: solid 1px $color--gray-2 !important;

    &--remove {
        border: none !important;
    }

    for dir in directions {
        &--{dir} {
            border-{dir}: @border;

            &-remove {
                border-{dir}: none !important;
            }
        }
    }

    for color in colors {
        &--{color} {
            if color == 'white' {
                border-color: #fff !important;
            }
            else {
                border-color: lookup('$color--ls-' + color) !important;
            }
        }
    }
}