papercss/src/flexbox.less

.center-all() {
    -webkit-align-items: center;
            align-items: center;
    -webkit-justify-content: center;
            justify-content: center;
}
.col-size(@percent) {
    -webkit-box-flex: 0;
    -webkit-flex: 0 0 @percent;
    -ms-flex: 0 0 @percent;
    flex: 0 0 @percent;
    max-width: @percent;
}
.generate-col(@n, @i: 1) when (@i =< @n) {
    @percent: (@i * 100% / @n);
    .col-@{i} {
        .col-size(@percent);
    }
    .generate-col(@n, (@i + 1));
}

.generate-sm(@n, @i: 1) when (@i =< @n) {
    @percent: (@i * 100% / @n);
    @media (min-width: 768px) {
        .sm-@{i} {
            .col-size(@percent);
        }
    }
    .generate-sm(@n, (@i + 1));
}
.generate-md(@n, @i: 1) when (@i =< @n) {
    @percent: (@i * 100% / @n);
    @media (min-width: 992px) {
        .md-@{i} {
            .col-size(@percent);
        }
    }
    .generate-md(@n, (@i + 1));
}
.generate-lg(@n, @i: 1) when (@i =< @n) {
    @percent: (@i * 100% / @n);
    @media (min-width: 1200px) {
        .lg-@{i} {
            .col-size(@percent);
        }
    }
    .generate-lg(@n, (@i + 1));
}
.generate-columns(@n) {
    .generate-col(@n);
    .generate-sm(@n);
    .generate-md(@n);
    .generate-lg(@n);
}
.row {
    margin-right: auto;
    margin-left: auto;
    display: -webkit-box;
    display: -webkit-flex;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: horizontal;
    -webkit-box-direction: normal;
    -webkit-flex-flow: row wrap;
    -ms-flex-flow: row wrap;
    flex-flow: row wrap;
    margin-bottom: 1rem;
    &.flex-right {
        -webkit-box-pack: end;
        -webkit-justify-content: flex-end;
        -ms-flex-pack: end;
        justify-content: flex-end;
    }
    &.flex-center {
        -webkit-box-pack: center;
        -webkit-justify-content: center;
        -ms-flex-pack: center;
        justify-content: center;
    }
    &.flex-edges {
        -webkit-box-pack: justify;
        -webkit-justify-content: space-between;
        -ms-flex-pack: justify;
        justify-content: space-between;
    }
    &.flex-spaces {
        -webkit-justify-content: space-around;
        -ms-flex-pack: distribute;
        justify-content: space-around;
    }
    &.flex-top {
        -webkit-box-align: start;
        -webkit-align-items: flex-start;
        -ms-flex-align: start;
        align-items: flex-start;
    }
    &.flex-middle {
        -webkit-box-align: center;
        -webkit-align-items: center;
        -ms-flex-align: center;
        align-items: center;
    }
    &.flex-bottom {
        -webkit-box-align: end;
        -webkit-align-items: flex-end;
        -ms-flex-align: end;
        align-items: flex-end;
    }
}
.col {
    padding: 1rem;
    @media (max-width: 767px) {
        // Stack for mobile
        .col-size(100%);
    }
}
.col-fill {
    width: auto;
    flex: 1 1 0px;
}
.generate-columns(12);
.align-top {
    -webkit-align-self: flex-start;
    -ms-flex-item-align: start;
    align-self: flex-start;
}
.align-middle {
    -webkit-align-self: center;
    -ms-flex-item-align: center;
    -ms-grid-row-align: center;
    align-self: center;
}
.align-bottom {
    -webkit-align-self: flex-end;
    -ms-flex-item-align: end;
    align-self: flex-end;
}