diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index f79dc36..690d610 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,29 +1,25 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout 
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:orientation="vertical"
     android:background="@drawable/bg_gradient">
 
-    <!-- 顶部菜单按钮 -->
+    <!-- 顶部栏 -->
     <LinearLayout
-        android:id="@+id/headerMenu"
-        android:layout_width="wrap_content"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         android:padding="16dp"
-        app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        android:gravity="end">
 
         <ImageView
             android:id="@+id/btnMore"
             android:layout_width="40dp"
             android:layout_height="40dp"
             android:src="@drawable/ic_more"
-            android:padding="8dp"
             android:background="@drawable/bg_menu_button"
+            android:padding="8dp"
             android:contentDescription="更多"/>
 
         <ImageView
@@ -31,8 +27,8 @@
             android:layout_width="40dp"
             android:layout_height="40dp"
             android:src="@drawable/ic_scan"
-            android:padding="8dp"
             android:background="@drawable/bg_menu_button"
+            android:padding="8dp"
             android:layout_marginStart="8dp"
             android:contentDescription="扫描"/>
     </LinearLayout>
@@ -40,17 +36,13 @@
     <!-- 搜索栏 -->
     <LinearLayout
         android:id="@+id/searchBar"
-        android:layout_width="0dp"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         android:background="@drawable/bg_search"
         android:padding="12dp"
-        android:layout_marginStart="16dp"
-        android:layout_marginEnd="16dp"
-        android:layout_marginTop="16dp"
-        app:layout_constraintTop_toBottomOf="@id/headerMenu"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        android:layout_margin="16dp"
+        android:gravity="center_vertical">
 
         <ImageView
             android:layout_width="24dp"
@@ -64,21 +56,16 @@
             android:text="@string/search_hint"
             android:textColor="#999999"
             android:textSize="16sp"
-            android:layout_marginStart="12dp"
-            android:layout_gravity="center_vertical"/>
+            android:layout_marginStart="12dp"/>
     </LinearLayout>
 
     <!-- 功能网格 -->
     <GridLayout
         android:id="@+id/functionGrid"
-        android:layout_width="0dp"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:columnCount="4"
-        android:rowCount="2"
-        android:padding="16dp"
-        app:layout_constraintTop_toBottomOf="@id/searchBar"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        android:padding="16dp">
 
         <!-- 备忘录 -->
         <LinearLayout
@@ -86,10 +73,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -113,10 +99,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -140,10 +125,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -167,10 +151,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -194,10 +177,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -221,10 +203,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -248,10 +229,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -275,10 +255,9 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_columnWeight="1"
-            android:layout_rowWeight="1"
             android:orientation="vertical"
             android:gravity="center"
-            android:padding="12dp">
+            android:padding="8dp">
 
             <ImageView
                 android:layout_width="48dp"
@@ -300,15 +279,13 @@
     <!-- 消息提示 -->
     <LinearLayout
         android:id="@+id/messageBanner"
-        android:layout_width="0dp"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         android:background="@drawable/bg_message"
         android:padding="12dp"
         android:layout_margin="16dp"
-        app:layout_constraintTop_toBottomOf="@id/functionGrid"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        android:gravity="center_vertical">
 
         <ImageView
             android:layout_width="24dp"
@@ -322,22 +299,18 @@
             android:text="@string/message_hint"
             android:textColor="#666666"
             android:textSize="14sp"
-            android:layout_marginStart="12dp"
-            android:layout_gravity="center_vertical"/>
+            android:layout_marginStart="12dp"/>
     </LinearLayout>
 
     <!-- 博客卡片 -->
     <LinearLayout
         android:id="@+id/blogCard"
-        android:layout_width="0dp"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="vertical"
         android:background="@drawable/bg_card"
         android:padding="16dp"
-        android:layout_margin="16dp"
-        app:layout_constraintTop_toBottomOf="@id/messageBanner"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        android:layout_margin="16dp">
 
         <TextView
             android:layout_width="wrap_content"
@@ -359,14 +332,12 @@
     <!-- 底部导航 -->
     <LinearLayout
         android:id="@+id/bottomNav"
-        android:layout_width="0dp"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         android:background="@android:color/white"
         android:elevation="8dp"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        android:layout_marginTop="0dp">
 
         <!-- 首页 -->
         <LinearLayout
@@ -436,4 +407,4 @@
         </LinearLayout>
     </LinearLayout>
 
-</androidx.constraintlayout.widget.ConstraintLayout>
+</LinearLayout>