.app-navback {
    position: fixed;
    left: 0;
    top: 0;
    z-index: 1;
    display: inline-flex;

    &:empty {
        display: none;
    }

    >.van-icon {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        height: var(--navbar-height);
        line-height: 1;
        font-size: .36rem;
        color: var(--navbar-backbutton-color);
        cursor: pointer;
        padding: 0 .28rem;
    }
}