.flex-columns {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
}

.flex-columns_item {
    text-align: center;
    width: calc(50% - 10px);
    padding: 0 5px;
    margin-bottom: 16px;
}

@media (min-width: 400px) {
    .flex-columns_item {
        width: calc(33% - 10px);
    }
}

@media (min-width: 720px) {
    .flex-columns_item {
        width: calc(25% - 10px);
    }
}

@media (min-width: 860px) {
    .flex-columns_item {
        width: calc(20% - 10px);
    }
}

@media (min-width: 915px) {
    .flex-columns_item {
        flex: 1 1 0;
    }
}