.Topbar {
    position: fixed;
    top: 0;
    z-index: 10;
    width: 100vw;
    height: 0.88rem;
    box-sizing: border-box;
    -webkit-transition: background 0.3s;
    transition: background 0.3s;
}

.Topbar.showBg {
    background: #152a95;
}

.Topbar .bar-child {
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100vw;
    height: 0.88rem;
}

.Topbar .back {
    position: absolute;
    left: 0;
    bottom: 0;
    transform: translateZ(0);
    width: 1.08rem;
    height: 0.88rem;
}

.Topbar .back .back-icon {
    width: 100%;
    height: 100%;
    background: url('../img/back.png') center no-repeat;
    background-size: 0.4rem auto;
}

.Topbar .title {
    flex: 1;
    color: #fff;
    font-size: 0.34rem;
    text-align: center;
}