.avatar {
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
    border-radius: 50%;
    height: 8rem;
    width: 8rem;
    background: #181;
    color: #fff;
    font-family: 'Microsoft JhengHei';
    margin: .3rem 0;
}

    .avatar .em1,
    .avatar .em2 {
        font-size: 3.5rem;
    }

    .avatar .em3 {
        font-size: 2.5rem;
    }

    .avatar .em4 {
        font-size: 2rem;
    }

.flex-center {
    display: flex;
    justify-content: center;
}