.van-cell { display: block }
.nav {
    position: sticky;
    top:0;
    background-color: #2fa0ec;
    color: #fff;
    height: 1.2rem;
    line-height: 1.2rem;
    text-align: center;
    font-size: 0.4rem;
    box-shadow: 0 0.027rem 0.107rem 0 rgba(74,74,78,.18) }
.logo {
    width: 3rem;
    height: 3rem;
}