twong329/view/xcx/pages/user_bill/index.wxss

.bill-details .nav {
    background-color: #fff;
    height: 90rpx;
    width: 100%;
    line-height: 90rpx;
}

.bill-details .nav .item {
    flex: 1;
    text-align: center;
    font-size: 30rpx;
    color: #282828;
}

.bill-details .nav .item.on {
    color: #e93323;
    border-bottom: 3rpx solid #e93323;
}