body{ 
    text-align: center;
    background : #eef; color: #222; display: flex; 
    flex-flow: column nowrap;justify-content: space-between; 
}


.header-container {background: #666; height: 60px;
    display: flex; flex-flow: row nowrap; justify-content: space-around; align-items: center;
}

.footer-container {background: #111;}