if you use like this your child content come with 100% height.you have to use "height: fit-content" and "display: flex;" along with "position:absolute;"

article {
    height: fit-content ; /* Add this line if its not working */
    display: flex;
    justify-content: space-between;
    flex-flow: row wrap;
    background: whitesmoke;
    position:absolute;
    top: 10px;
    left: 10px;
    bottom: 10px;
  
}

check this sample "https://codepen.io/kuttisenthil/pen/ZYELWaP"