HarmonyOS scroll 内控件布局问题

@Entry  
@Component  
struct Index {  
  build() {  
    Column() {  
      Column().backgroundColor(Color.Green)  
        .height('10%')  
        .width('100%')  
      Flex({ direction: FlexDirection.Column }) {  
        Scroll() {  
          Column() {  
            Column().width('100%').height("500vp")  
              .justifyContent(FlexAlign.Start)  
              .backgroundColor(Color.Blue)  
          }  
        }  
      }  
      .height('80%')  
      Column().backgroundColor(Color.Green)  
        .height('10%')  
        .width('100%')  
    }.width('100%')  
    .height('100%')  
    .backgroundColor('#F6F6F6')  
  }  
}