HarmonyOS 鸿蒙Next tabbar的样式和位置可以自己定义吗

可以的，参考demo:

[@Entry](/user/Entry)
[@Component](/user/Component)
struct TabsSample {
  [@State](/user/State) currentIndex: number = 0;

  [@Builder](/user/Builder) TabBuilder(index: number, name: string) {
    Text(name)
      .fontColor(this.currentIndex === index ? Color.White : Color.Black)
      .fontSize(this.currentIndex === index ? 18 : 16)
      .fontWeight(this.currentIndex === index ? 500 : 400)
      .textAlign(TextAlign.Center)
      .width(100)
      .height(48)
      .margin({ left: 4, right: 4 })
      .backgroundColor(this.currentIndex === index ? '#007DFF' : '#F1F3F5')
      .borderRadius(24)
  }

  build() {
    Column() {
      Tabs({ index: this.currentIndex }) {
        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#00CB87')
        }.tabBar(this.TabBuilder(0, 'green'))

        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#007DFF')
        }.tabBar(this.TabBuilder(1, 'blue'))

        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#FFBF00')
        }.tabBar(this.TabBuilder(2, 'yellow'))

        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#E67C92')
        }.tabBar(this.TabBuilder(3, 'pink'))
      }
      .height(300)
      .barMode(BarMode.Scrollable, { margin: 16 })
      .fadingEdge(false)
      .animationDuration(0)
      .onChange((index: number) => {
        this.currentIndex = index
      })
    }.width('100%')
  }
}