remove useless constraintlayout dep
diff --git a/app/build.gradle b/app/build.gradle
index db60a16..b30bfaf 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -56,5 +56,4 @@
 
 	implementation "androidx.annotation:annotation:1.6.0"
 	implementation "androidx.cardview:cardview:1.0.0"
-	implementation "androidx.constraintlayout:constraintlayout:2.1.4"
 }
diff --git a/app/src/main/Android.bp b/app/src/main/Android.bp
index d109a4e..fbcbd66 100644
--- a/app/src/main/Android.bp
+++ b/app/src/main/Android.bp
@@ -12,7 +12,6 @@
     static_libs: [
         "androidx.annotation_annotation",
         "androidx.cardview_cardview",
-        "androidx-constraintlayout_constraintlayout",
         "LMOFaceShared",
         "android.hardware.biometrics.face-V1.0-java",
     ],
diff --git a/app/src/main/res/layout/activity_enroll.xml b/app/src/main/res/layout/activity_enroll.xml
index d25d705..af18318 100644
--- a/app/src/main/res/layout/activity_enroll.xml
+++ b/app/src/main/res/layout/activity_enroll.xml
@@ -1,21 +1,18 @@
 <?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"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
 	android:layout_height="match_parent"
+	android:orientation="vertical"
+	android:gravity="center"
 	tools:context=".ScanActivity">
 
 	<ImageView
 		android:id="@+id/imageView"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
+		android:layout_marginTop="50dp"
 		android:tint="?android:attr/colorAccent"
-		app:layout_constraintBottom_toBottomOf="parent"
-		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toTopOf="parent"
-		app:layout_constraintVertical_bias="0.05"
 		android:src="@drawable/baseline_face_retouching_natural_24"
 		android:contentDescription="@null" />
 
@@ -25,10 +22,14 @@
 		android:layout_height="wrap_content"
 		android:text="@string/face_unlock"
 		android:textAppearance="@android:style/TextAppearance.DeviceDefault.Large"
-		android:textColor="?android:attr/colorAccent"
-		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toBottomOf="@+id/imageView" />
+		android:textColor="?android:attr/colorAccent" />
+
+	<FrameLayout
+		android:id="@+id/frameLayout"
+		android:layout_weight="1"
+		android:layout_width="match_parent"
+		android:layout_height="0dp"
+		android:layout_margin="30dp" />
 
 	<Button
 		android:id="@+id/button"
@@ -36,21 +37,8 @@
 		android:layout_height="wrap_content"
 		android:layout_margin="20dp"
 		android:background="@drawable/btn_bg"
+		android:layout_gravity="start"
 		android:shadowRadius="0"
 		android:textColor="?android:attr/textColorPrimaryInverse"
-		android:text="@string/cancel"
-		app:layout_constraintBottom_toBottomOf="parent"
-		app:layout_constraintStart_toStartOf="parent" />
-
-	<FrameLayout
-		android:id="@+id/frameLayout"
-		android:layout_width="0dp"
-		android:layout_height="0dp"
-		android:layout_margin="30dp"
-		app:layout_constraintBottom_toTopOf="@+id/button"
-		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toBottomOf="@+id/textView">
-
-	</FrameLayout>
-</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
+		android:text="@string/cancel" />
+</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/enroll_main.xml b/app/src/main/res/layout/enroll_main.xml
index 9f500ae..9c20737 100644
--- a/app/src/main/res/layout/enroll_main.xml
+++ b/app/src/main/res/layout/enroll_main.xml
@@ -30,7 +30,6 @@
 	<androidx.cardview.widget.CardView
 		android:layout_width="300dp"
 		android:layout_height="300dp"
-		android:orientation="vertical"
 		app:cardCornerRadius="360dp">
 
 		<com.libremobileos.yifan.face.AutoFitTextureView