.flex{
    display: -webkit-flex;
    display: flex;
    flex-basis : auto;
}

.flex-middle{
    vertical-align: middle;
    -webkit-align-items: center;
            align-items: center;
}

.spacer{
    box-flex: 1!important;
    -webkit-box-flex: 1!important;
    -ms-flex-positive: 1!important;
    flex-grow : 1 !important;
}

.fill{
    height: 100%;
    overflow-y: auto;
}