.col-top {
    vertical-align: top;
}

.col-middle {
    position: relative;
}

.col-bottom {
    vertical-align: bottom;
}

/* columns of same height styles */

.row-full-height {
    height: 100%;
}

.col-full-height {
    height: 100%;
    vertical-align: middle;
}

.row-same-height {
    display: block;
    width: 100%;
    position: relative;
    /* fix overflow */
    /*table-layout: fixed;*/
}

.col-xs-height {
    display: block;
    float: none !important;
}

@media (min-width: 768px) {
    .col-sm-height {
        display: block;
        float: none !important;
    }
    .col-back-btn{
        position: absolute;
    }
    .col-middle{
        top: 50%;
        -webkit-transform: translateY(-50%);
        -ms-transform: translateY(-50%);
        transform: translateY(-50%);
    }
}

@media (min-width: 992px) {
    .col-md-height {
        display: block;
        float: none !important;
    }
}

@media (min-width: 1200px) {
    .col-lg-height {
        display: block;
        float: none !important;
    }
}

/* content styles */

.item {
    display: table;
}

.content {
    display: table-cell;
    vertical-align: middle;
    text-align: center;
}