style.css

.coin {
    height: 50px;
    width: 50px;
    border-radius: 25px;
    background-color: grey;
    text-align: center;
    font-weight: bold;
    font-family: sans-serif;
    color: white;
    margin: 10px;
    display: inline-block;
    line-height: 50px;
    font-size: 20px;
}