feat: improve header ui

app/src/main/res/layout/fragment_header.xml

@@ -13,6 +13,8 @@
         android:layout_height="wrap_content"
         android:layout_alignParentTop="true"
         android:text="Hello Blank Fragment"
+        android:textColor="@color/black"
+        android:fontFamily="@font/open_sans_bold"
         android:textAlignment="center"
         android:textSize="24sp"
         app:layout_constraintEnd_toEndOf="parent"