Align items to bottom while maintaining stretch in flexbox

I'm using flexbox to build the following layout of cards

.card {    flex-basis: calc(100% - 40px);    border-radius: 4px;}.card__content {    padding: 25px;}.card__footer {    display: flex;    justify-content: space-between;    padding: 10px 25px;}

I'm trying to achieve that the card__footer is always aligned to the bottom. When I try by adding the following code, I lose my stretch and the items are not the same height anymore

.card {margin-bottom: auto;}

Any idea in what direction I have to look for a solution?