div.hidden {
    display: none
}

.row.equal-cols {
    display: -webkit-flex;
    display: -ms-flexbox;
    display: flex;
    -webkit-flex-wrap: wrap;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
}

.row.equal-cols:before,
.row.equal-cols:after {
    display: block;
}

.row.equal-cols > [class*='col-'] {
    display: -webkit-flex;
    display: -ms-flexbox;
    display: flex;
    -webkit-flex-direction: column;
    -ms-flex-direction: column;
    flex-direction: column;
}

.row.equal-cols > [class*='col-'] > * {
    -webkit-flex: 1 1 auto;
    -ms-flex: 1 1 auto;
    flex: 1 1 auto;
}