给item单独设置宽度，使滑块计算准确

::v-deep .u-scroll-box .u-tab-item {
    width: 80px !important;
    &:nth-child(3),
    &:nth-child(4),
    &:nth-child(5) {
        width: 60px !important;
    }
    flex: 1 1 0% !important;
}

效果如下：