taro/src/custom-tab-bar/index.scss

.tabbar{
    display: flex;
    flex-direction: row;
    justify-content: space-around;
    background-color: #000;
    // background-color: red;
    padding-bottom: constant(safe-area-inset-bottom);
    /* 兼容 iOS < 11.2 */
    padding-bottom: env(safe-area-inset-bottom);
}

.tabbar-item{
    color: #fff;
    padding-top: 25px;
}