.container {
    width: 100%;
    height: 100%;
    position: absolute;    
    margin:auto;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: #FFFFFF;
    }
img {
    max-width: 80%;
    max-height: 80%;  
    position: absolute;
    margin:auto;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    }