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

.roll {
    flex: 1;
    width: 100%;
    overflow-y: scroll;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    height: auto;
}
.nav-footer {
    color: #8d8d9c;
    background: #fbfcfc;
    border-top: 1px solid #e5e5e5;
    width: 100%;
    height: 4rem;
    font-size: 14px;
}
.nav-item {
    display: flex;
    flex-direction: column;
    flex: 1;
    justify-content: center;
    align-content: stretch;
    align-items: center;
    font-size: 14px;
}
.nav-active {
    color: #ff4545;
}
a.nav-active {
    color: #ff4545;
}