.container {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    -webkit-flex-flow: column;
    flex-flow: column;
    -webkit-flex-wrap: nowrap;
    flex-wrap: nowrap;
}

header {
    -webkit-flex-shrink: 0;
    flex-shrink: 0;
    overflow: hidden
}
.body{
    -webkit-flex-grow: 1;
    flex-grow: 1;
    overflow: auto;
    min-height: 2em;
    position: relative;
}
footer{
    -webkit-flex-shrink: 0;
    flex-shrink: 0;
    overflow: hidden
}