html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    width: 100%;
    background: #f7f7f7;
    font-size: 12px;
}

.box {
    display: flex;
    display: -webkit-flex;
    height: 100%;
    flex-direction: column;
}

.roll {
    flex: 1;
    width: 100%;
    overflow-y: scroll;
    -webkit-overflow-scrolling: touch;
    height: auto;
}