Feat: 添加跳转计算 BMI 按钮

entry/src/main/ets/pages/Hello.ets

@@ -29,7 +29,7 @@ struct Hello {
           let uiContext: UIContext = this.getUIContext();
           let router = uiContext.getRouter();
           router.pushUrl({
-            url: 'pages/Second'
+            url: 'pages/Text'
           }).then(() => {
             console.log('系统提示：跳转成功')
           })

entry/src/main/ets/pages/Index.ets

@@ -7,18 +7,38 @@ struct Index {
   private scroller: Scroller = new Scroller();
 
   build() {
-    Scroll(this.scroller) {
+    Stack() {
+      Scroll(this.scroller) {
+        Column() {
+          Module0()
+          Module1()
+        }
+        .width('100%')
+      }
+      .scrollable(ScrollDirection.Vertical)
+      .scrollBar(BarState.Off)
+      .width('100%')
+      .height('100%')
+      .align(Alignment.Top)
+      .backgroundColor($r('app.color.page_bg_color'))
+
+      // 底部按钮
       Column() {
-        Module0()
-        Module1()
+        Button('[前往] 计算我的 BMI')
+          .width('80%')
+          .height(50)
+          .type(ButtonType.Capsule)
+          .fontSize(18)
+          .fontWeight(FontWeight.Medium)
+          .backgroundColor('#4C61E4')
+          .margin({ bottom: 20 })
       }
       .width('100%')
+      .height('100%')
+      .justifyContent(FlexAlign.End)
+      .alignItems(HorizontalAlign.Center)
     }
-    .scrollable(ScrollDirection.Vertical)
-    .scrollBar(BarState.Off)
     .width('100%')
     .height('100%')
-    .align(Alignment.Top)
-    .backgroundColor($r('app.color.page_bg_color'))
   }
 }