diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 324d225..618ee71 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -7,6 +7,7 @@
     tools:context=".MainActivity">
 
     <TextView
+        android:id="@+id/textView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Hello World!"
@@ -19,8 +20,12 @@
         android:id="@+id/start_button"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:layout_marginEnd="8dp"
         android:text="Button"
-        tools:layout_editor_absoluteX="161dp"
-        tools:layout_editor_absoluteY="375dp" />
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView" />
 
 </android.support.constraint.ConstraintLayout>
\ No newline at end of file