share_activity/components/topbar.wxss

/* components/topbar.wxss */

.topbar {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 999;
}

.topbar .back {
    width: 36rpx;
    height: 36rpx;
    position: absolute;
    left: 0;
    top: 0;
}
.topbar .back image {
    width: 20rpx;
    height: 36rpx;
}
.topbar .title {
    width: calc(100vw - 60rpx);
    height: 100%;
    text-align: center;
    font-size: 32rpx;
}