body{display:center;align-items:center;display:flex;flex-direction:column;padding:100px}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.row{display:flex;flex-direction:row;gap:10px}.card{width:30px;height:50px;border:1px solid gray}.front{background-color:white}.back{background-color:gray}