diff --git a/app/src/main/res/drawable-v21/widget_button_no_bg.xml b/app/src/main/res/drawable-v21/widget_button_no_bg.xml
new file mode 100644
index 00000000..3fe76bfa
--- /dev/null
+++ b/app/src/main/res/drawable-v21/widget_button_no_bg.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<ripple xmlns:a="http://schemas.android.com/apk/res/android"
+    a:color="@color/button_material_dark">
+    <item>
+        <shape>
+            <solid a:color="@color/cpp_editor_bg" />
+        </shape>
+    </item>
+</ripple>
diff --git a/app/src/main/res/drawable-v21/widget_button_no_bg_light.xml b/app/src/main/res/drawable-v21/widget_button_no_bg_light.xml
new file mode 100644
index 00000000..2d3bcc9d
--- /dev/null
+++ b/app/src/main/res/drawable-v21/widget_button_no_bg_light.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<ripple xmlns:a="http://schemas.android.com/apk/res/android"
+    a:color="@color/button_material_light">
+    <item>
+        <shape>
+            <solid a:color="@color/cpp_bg_light" />
+        </shape>
+    </item>
+</ripple>
diff --git a/app/src/main/res/drawable/widget_button_no_bg.xml b/app/src/main/res/drawable/widget_button_no_bg.xml
new file mode 100644
index 00000000..e343e5c7
--- /dev/null
+++ b/app/src/main/res/drawable/widget_button_no_bg.xml
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<selector xmlns:a="http://schemas.android.com/apk/res/android">
+
+    <item a:drawable="@drawable/widget_button_no_bg_pressed" a:state_pressed="true" />
+    <item>
+        <shape>
+            <solid a:color="@android:color/transparent" />
+        </shape>
+    </item>
+
+</selector>
\ No newline at end of file
diff --git a/app/src/main/res/drawable/widget_button_no_bg_light.xml b/app/src/main/res/drawable/widget_button_no_bg_light.xml
new file mode 100644
index 00000000..e343e5c7
--- /dev/null
+++ b/app/src/main/res/drawable/widget_button_no_bg_light.xml
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<selector xmlns:a="http://schemas.android.com/apk/res/android">
+
+    <item a:drawable="@drawable/widget_button_no_bg_pressed" a:state_pressed="true" />
+    <item>
+        <shape>
+            <solid a:color="@android:color/transparent" />
+        </shape>
+    </item>
+
+</selector>
\ No newline at end of file
diff --git a/app/src/main/res/drawable/widget_button_no_bg_pressed.xml b/app/src/main/res/drawable/widget_button_no_bg_pressed.xml
new file mode 100644
index 00000000..84bc16fe
--- /dev/null
+++ b/app/src/main/res/drawable/widget_button_no_bg_pressed.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<shape xmlns:a="http://schemas.android.com/apk/res/android">
+    <solid a:color="#664d4d4d" />
+</shape>
diff --git a/app/src/main/res/layout/cpp_simple_button_clear_material.xml b/app/src/main/res/layout/cpp_simple_button_clear_material.xml
index 8ea12273..51c66f70 100644
--- a/app/src/main/res/layout/cpp_simple_button_clear_material.xml
+++ b/app/src/main/res/layout/cpp_simple_button_clear_material.xml
@@ -25,6 +25,6 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_clear"
-    style="@style/CppKeyboardButton.Material.Simple.Control"
+    style="@style/CppKeyboardButton.Material.Simple.Control.Highlighted"
     a:text="@string/c_clear"
     a:textStyle="bold" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_clear_material_light.xml b/app/src/main/res/layout/cpp_simple_button_clear_material_light.xml
index ed98c597..e7aad087 100644
--- a/app/src/main/res/layout/cpp_simple_button_clear_material_light.xml
+++ b/app/src/main/res/layout/cpp_simple_button_clear_material_light.xml
@@ -25,6 +25,6 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_clear"
-    style="@style/CppKeyboardButton.Material.Light.Simple.Control"
+    style="@style/CppKeyboardButton.Material.Light.Simple.Control.Highlighted"
     a:text="@string/c_clear"
     a:textStyle="bold" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_equals.xml b/app/src/main/res/layout/cpp_simple_button_equals.xml
index 367c15f4..240d3cd9 100644
--- a/app/src/main/res/layout/cpp_simple_button_equals.xml
+++ b/app/src/main/res/layout/cpp_simple_button_equals.xml
@@ -24,5 +24,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_equals"
-    style="@style/CppKeyboardButton.Metro.Simple.Control"
+    style="@style/CppKeyboardButton.Metro.Simple.NoBg"
     a:text="=" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_equals_material.xml b/app/src/main/res/layout/cpp_simple_button_equals_material.xml
index 7752b9ed..3321a2fa 100644
--- a/app/src/main/res/layout/cpp_simple_button_equals_material.xml
+++ b/app/src/main/res/layout/cpp_simple_button_equals_material.xml
@@ -24,5 +24,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_equals"
-    style="@style/CppKeyboardButton.Material.Simple.Control"
+    style="@style/CppKeyboardButton.Material.Simple.NoBg"
     a:text="=" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_equals_material_light.xml b/app/src/main/res/layout/cpp_simple_button_equals_material_light.xml
index 1e6b7308..4f4760d1 100644
--- a/app/src/main/res/layout/cpp_simple_button_equals_material_light.xml
+++ b/app/src/main/res/layout/cpp_simple_button_equals_material_light.xml
@@ -24,5 +24,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_equals"
-    style="@style/CppKeyboardButton.Material.Light.Simple.Control"
+    style="@style/CppKeyboardButton.Material.Light.Simple.NoBg"
     a:text="=" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_erase.xml b/app/src/main/res/layout/cpp_simple_button_erase.xml
index ff6964e8..6bed7330 100644
--- a/app/src/main/res/layout/cpp_simple_button_erase.xml
+++ b/app/src/main/res/layout/cpp_simple_button_erase.xml
@@ -25,6 +25,6 @@
 <ImageButton
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_erase"
-    style="@style/CppKeyboardButton.Metro.Simple.Control.Image"
+    style="@style/CppKeyboardButton.Metro.Simple.Operation.Image"
     a:contentDescription="Erase"
     a:src="@drawable/ic_backspace_white_48dp" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_erase_material.xml b/app/src/main/res/layout/cpp_simple_button_erase_material.xml
index be559021..a3de09bb 100644
--- a/app/src/main/res/layout/cpp_simple_button_erase_material.xml
+++ b/app/src/main/res/layout/cpp_simple_button_erase_material.xml
@@ -25,6 +25,6 @@
 <ImageButton
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_erase"
-    style="@style/CppKeyboardButton.Material.Simple.Control.Image"
+    style="@style/CppKeyboardButton.Material.Simple.Control.Image.Highlighted"
     a:contentDescription="Erase"
     a:src="@drawable/ic_backspace_white_48dp" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_erase_material_light.xml b/app/src/main/res/layout/cpp_simple_button_erase_material_light.xml
index 6431333b..f564402f 100644
--- a/app/src/main/res/layout/cpp_simple_button_erase_material_light.xml
+++ b/app/src/main/res/layout/cpp_simple_button_erase_material_light.xml
@@ -25,6 +25,6 @@
 <ImageButton
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_erase"
-    style="@style/CppKeyboardButton.Material.Light.Simple.Control.Image"
+    style="@style/CppKeyboardButton.Material.Light.Simple.Control.Image.Highlighted"
     a:contentDescription="Erase"
     a:src="@drawable/ic_backspace_white_48dp" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_percent.xml b/app/src/main/res/layout/cpp_simple_button_percent.xml
index 4e7104c8..53cfa9a6 100644
--- a/app/src/main/res/layout/cpp_simple_button_percent.xml
+++ b/app/src/main/res/layout/cpp_simple_button_percent.xml
@@ -25,5 +25,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_percent"
-    style="@style/CppKeyboardButton.Metro.Simple.Operation"
+    style="@style/CppKeyboardButton.Metro.Simple.Control"
     a:text="%" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_percent_material.xml b/app/src/main/res/layout/cpp_simple_button_percent_material.xml
index c90c2aea..15fe1ac3 100644
--- a/app/src/main/res/layout/cpp_simple_button_percent_material.xml
+++ b/app/src/main/res/layout/cpp_simple_button_percent_material.xml
@@ -25,5 +25,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_percent"
-    style="@style/CppKeyboardButton.Material.Simple.Operation"
+    style="@style/CppKeyboardButton.Material.Simple.Digit"
     a:text="%" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_percent_material_light.xml b/app/src/main/res/layout/cpp_simple_button_percent_material_light.xml
index 226109e3..8a3a5a39 100644
--- a/app/src/main/res/layout/cpp_simple_button_percent_material_light.xml
+++ b/app/src/main/res/layout/cpp_simple_button_percent_material_light.xml
@@ -25,5 +25,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_percent"
-    style="@style/CppKeyboardButton.Material.Light.Simple.Operation"
+    style="@style/CppKeyboardButton.Material.Light.Simple.Digit"
     a:text="%" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_power.xml b/app/src/main/res/layout/cpp_simple_button_power.xml
index c9ca18ea..45ee1346 100644
--- a/app/src/main/res/layout/cpp_simple_button_power.xml
+++ b/app/src/main/res/layout/cpp_simple_button_power.xml
@@ -25,5 +25,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_power"
-    style="@style/CppKeyboardButton.Metro.Simple.Operation"
+    style="@style/CppKeyboardButton.Metro.Simple.Control"
     a:text="^" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_power_material.xml b/app/src/main/res/layout/cpp_simple_button_power_material.xml
index f10ad35b..b377b28f 100644
--- a/app/src/main/res/layout/cpp_simple_button_power_material.xml
+++ b/app/src/main/res/layout/cpp_simple_button_power_material.xml
@@ -25,5 +25,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_power"
-    style="@style/CppKeyboardButton.Material.Simple.Operation"
+    style="@style/CppKeyboardButton.Material.Simple.Digit"
     a:text="^" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/cpp_simple_button_power_material_light.xml b/app/src/main/res/layout/cpp_simple_button_power_material_light.xml
index 7d10604a..ce3b2e44 100644
--- a/app/src/main/res/layout/cpp_simple_button_power_material_light.xml
+++ b/app/src/main/res/layout/cpp_simple_button_power_material_light.xml
@@ -25,5 +25,5 @@
 <Button
     xmlns:a="http://schemas.android.com/apk/res/android"
     a:id="@id/cpp_button_power"
-    style="@style/CppKeyboardButton.Material.Light.Simple.Operation"
+    style="@style/CppKeyboardButton.Material.Light.Simple.Digit"
     a:text="^" />
\ No newline at end of file
diff --git a/app/src/main/res/layout/onscreen_keyboard.xml b/app/src/main/res/layout/onscreen_keyboard.xml
deleted file mode 100644
index dde9613e..00000000
--- a/app/src/main/res/layout/onscreen_keyboard.xml
+++ /dev/null
@@ -1,75 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-    a:layout_width="match_parent"
-    a:layout_height="match_parent"
-    a:orientation="vertical">
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_7" />
-
-        <include layout="@layout/cpp_simple_button_8" />
-
-        <include layout="@layout/cpp_simple_button_9" />
-
-        <include layout="@layout/cpp_simple_button_multiplication" />
-
-        <include layout="@layout/cpp_simple_button_erase" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_4" />
-
-        <include layout="@layout/cpp_simple_button_5" />
-
-        <include layout="@layout/cpp_simple_button_6" />
-
-        <include layout="@layout/cpp_simple_button_division" />
-
-        <include layout="@layout/cpp_simple_button_percent" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_1" />
-
-        <include layout="@layout/cpp_simple_button_2" />
-
-        <include layout="@layout/cpp_simple_button_3" />
-
-        <include layout="@layout/cpp_simple_button_plus" />
-
-        <include layout="@layout/cpp_simple_button_power" />
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_round_brackets" />
-
-        <include layout="@layout/cpp_simple_button_0" />
-
-        <include layout="@layout/cpp_simple_button_dot" />
-
-        <include layout="@layout/cpp_simple_button_minus" />
-
-        <include layout="@layout/cpp_simple_button_app" />
-
-    </LinearLayout>
-
-</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/onscreen_keyboard_material.xml b/app/src/main/res/layout/onscreen_keyboard_material.xml
deleted file mode 100644
index c7e15307..00000000
--- a/app/src/main/res/layout/onscreen_keyboard_material.xml
+++ /dev/null
@@ -1,75 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-    a:layout_width="match_parent"
-    a:layout_height="match_parent"
-    a:orientation="vertical">
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_7_material" />
-
-        <include layout="@layout/cpp_simple_button_8_material" />
-
-        <include layout="@layout/cpp_simple_button_9_material" />
-
-        <include layout="@layout/cpp_simple_button_multiplication_material" />
-
-        <include layout="@layout/cpp_simple_button_erase_material" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_4_material" />
-
-        <include layout="@layout/cpp_simple_button_5_material" />
-
-        <include layout="@layout/cpp_simple_button_6_material" />
-
-        <include layout="@layout/cpp_simple_button_division_material" />
-
-        <include layout="@layout/cpp_simple_button_percent_material" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_1_material" />
-
-        <include layout="@layout/cpp_simple_button_2_material" />
-
-        <include layout="@layout/cpp_simple_button_3_material" />
-
-        <include layout="@layout/cpp_simple_button_plus_material" />
-
-        <include layout="@layout/cpp_simple_button_power_material" />
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_round_brackets_material" />
-
-        <include layout="@layout/cpp_simple_button_0_material" />
-
-        <include layout="@layout/cpp_simple_button_dot_material" />
-
-        <include layout="@layout/cpp_simple_button_minus_material" />
-
-        <include layout="@layout/cpp_simple_button_app_material" />
-
-    </LinearLayout>
-
-</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/onscreen_keyboard_material_light.xml b/app/src/main/res/layout/onscreen_keyboard_material_light.xml
deleted file mode 100644
index 2f8e89b5..00000000
--- a/app/src/main/res/layout/onscreen_keyboard_material_light.xml
+++ /dev/null
@@ -1,75 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-    a:layout_width="match_parent"
-    a:layout_height="match_parent"
-    a:orientation="vertical">
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_7_material_light" />
-
-        <include layout="@layout/cpp_simple_button_8_material_light" />
-
-        <include layout="@layout/cpp_simple_button_9_material_light" />
-
-        <include layout="@layout/cpp_simple_button_multiplication_material_light" />
-
-        <include layout="@layout/cpp_simple_button_erase_material_light" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_4_material_light" />
-
-        <include layout="@layout/cpp_simple_button_5_material_light" />
-
-        <include layout="@layout/cpp_simple_button_6_material_light" />
-
-        <include layout="@layout/cpp_simple_button_division_material_light" />
-
-        <include layout="@layout/cpp_simple_button_percent_material_light" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_1_material_light" />
-
-        <include layout="@layout/cpp_simple_button_2_material_light" />
-
-        <include layout="@layout/cpp_simple_button_3_material_light" />
-
-        <include layout="@layout/cpp_simple_button_plus_material_light" />
-
-        <include layout="@layout/cpp_simple_button_power_material_light" />
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_round_brackets_material_light" />
-
-        <include layout="@layout/cpp_simple_button_0_material_light" />
-
-        <include layout="@layout/cpp_simple_button_dot_material_light" />
-
-        <include layout="@layout/cpp_simple_button_minus_material_light" />
-
-        <include layout="@layout/cpp_simple_button_app_material_light" />
-
-    </LinearLayout>
-
-</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/onscreen_layout.xml b/app/src/main/res/layout/onscreen_layout.xml
index af3d2101..18a0c004 100644
--- a/app/src/main/res/layout/onscreen_layout.xml
+++ b/app/src/main/res/layout/onscreen_layout.xml
@@ -35,15 +35,15 @@
                 layout="@layout/onscreen_display"
                 a:layout_width="0dp"
                 a:layout_height="match_parent"
-                a:layout_weight="4" />
+                a:layout_weight="5" />
 
         </LinearLayout>
 
         <include
-            layout="@layout/onscreen_keyboard"
+            layout="@layout/widget_keyboard"
             a:layout_width="match_parent"
             a:layout_height="0dp"
-            a:layout_weight="4" />
+            a:layout_weight="5" />
     </LinearLayout>
 
 </LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/onscreen_layout_material.xml b/app/src/main/res/layout/onscreen_layout_material.xml
index 66e36675..1b5fa694 100644
--- a/app/src/main/res/layout/onscreen_layout_material.xml
+++ b/app/src/main/res/layout/onscreen_layout_material.xml
@@ -36,15 +36,15 @@
                 layout="@layout/onscreen_display"
                 a:layout_width="0dp"
                 a:layout_height="match_parent"
-                a:layout_weight="4" />
+                a:layout_weight="5" />
 
         </LinearLayout>
 
         <include
-            layout="@layout/onscreen_keyboard_material"
+            layout="@layout/widget_keyboard_material"
             a:layout_width="match_parent"
             a:layout_height="0dp"
-            a:layout_weight="4" />
+            a:layout_weight="5" />
     </LinearLayout>
 
 </LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/onscreen_layout_material_light.xml b/app/src/main/res/layout/onscreen_layout_material_light.xml
index f3249ef1..229de09a 100644
--- a/app/src/main/res/layout/onscreen_layout_material_light.xml
+++ b/app/src/main/res/layout/onscreen_layout_material_light.xml
@@ -35,15 +35,15 @@
                 layout="@layout/onscreen_display_light"
                 a:layout_width="0dp"
                 a:layout_height="match_parent"
-                a:layout_weight="4" />
+                a:layout_weight="5" />
 
         </LinearLayout>
 
         <include
-            layout="@layout/onscreen_keyboard_material_light"
+            layout="@layout/widget_keyboard_material_light"
             a:layout_width="match_parent"
             a:layout_height="0dp"
-            a:layout_weight="4" />
+            a:layout_weight="5" />
     </LinearLayout>
 
 </LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/widget_keyboard.xml b/app/src/main/res/layout/widget_keyboard.xml
index 22cf77d8..c7b7734e 100644
--- a/app/src/main/res/layout/widget_keyboard.xml
+++ b/app/src/main/res/layout/widget_keyboard.xml
@@ -32,16 +32,16 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_7" />
-
-        <include layout="@layout/cpp_simple_button_8" />
-
-        <include layout="@layout/cpp_simple_button_9" />
-
-        <include layout="@layout/cpp_simple_button_multiplication" />
-
         <include layout="@layout/cpp_simple_button_percent" />
 
+        <include layout="@layout/cpp_simple_button_left" />
+
+        <include layout="@layout/cpp_simple_button_right" />
+
+        <include layout="@layout/cpp_simple_button_settings" />
+
+        <include layout="@layout/cpp_simple_button_erase" />
+
         <include layout="@layout/cpp_simple_button_clear" />
 
     </LinearLayout>
@@ -51,35 +51,16 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_4" />
+        <include layout="@layout/cpp_simple_button_functions" />
 
-        <include layout="@layout/cpp_simple_button_5" />
+        <include layout="@layout/cpp_simple_button_7" />
 
-        <include layout="@layout/cpp_simple_button_6" />
+        <include layout="@layout/cpp_simple_button_8" />
+
+        <include layout="@layout/cpp_simple_button_9" />
 
         <include layout="@layout/cpp_simple_button_division" />
 
-        <include layout="@layout/cpp_simple_button_power" />
-
-        <include layout="@layout/cpp_simple_button_erase" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_1" />
-
-        <include layout="@layout/cpp_simple_button_2" />
-
-        <include layout="@layout/cpp_simple_button_3" />
-
-        <include layout="@layout/cpp_simple_button_plus" />
-
-        <include layout="@layout/cpp_simple_button_settings" />
-
         <include layout="@layout/cpp_simple_button_copy" />
 
     </LinearLayout>
@@ -89,36 +70,54 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_round_brackets" />
+        <include layout="@layout/cpp_simple_button_vars" />
 
-        <include layout="@layout/cpp_simple_button_0" />
+        <include layout="@layout/cpp_simple_button_4" />
 
-        <include layout="@layout/cpp_simple_button_dot" />
+        <include layout="@layout/cpp_simple_button_5" />
 
-        <include layout="@layout/cpp_simple_button_minus" />
+        <include layout="@layout/cpp_simple_button_6" />
 
-        <include layout="@layout/cpp_simple_button_app" />
+        <include layout="@layout/cpp_simple_button_multiplication" />
 
         <include layout="@layout/cpp_simple_button_paste" />
 
     </LinearLayout>
 
-
     <LinearLayout
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_left" />
-
-        <include layout="@layout/cpp_simple_button_right" />
-
-        <include layout="@layout/cpp_simple_button_vars" />
-
-        <include layout="@layout/cpp_simple_button_functions" />
-
         <include layout="@layout/cpp_simple_button_operators" />
 
+        <include layout="@layout/cpp_simple_button_1" />
+
+        <include layout="@layout/cpp_simple_button_2" />
+
+        <include layout="@layout/cpp_simple_button_3" />
+
+        <include layout="@layout/cpp_simple_button_minus" />
+
+        <include layout="@layout/cpp_simple_button_app" />
+
+    </LinearLayout>
+
+    <LinearLayout
+        a:layout_width="match_parent"
+        a:layout_height="0dp"
+        a:layout_weight="1">
+
+        <include layout="@layout/cpp_simple_button_power" />
+
+        <include layout="@layout/cpp_simple_button_0" />
+
+        <include layout="@layout/cpp_simple_button_dot" />
+
+        <include layout="@layout/cpp_simple_button_round_brackets" />
+
+        <include layout="@layout/cpp_simple_button_plus" />
+
         <include layout="@layout/cpp_simple_button_history" />
 
     </LinearLayout>
diff --git a/app/src/main/res/layout/widget_keyboard_material.xml b/app/src/main/res/layout/widget_keyboard_material.xml
index a63cc31a..a6852bf8 100644
--- a/app/src/main/res/layout/widget_keyboard_material.xml
+++ b/app/src/main/res/layout/widget_keyboard_material.xml
@@ -12,7 +12,8 @@
   ~ Unless required by applicable law or agreed to in writing, software
   ~ distributed under the License is distributed on an "AS IS" BASIS,
   ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
+  ~ See the Licens        <item name="android:background">@drawable/material_button_light_darker</item>
+e for the specific language governing permissions and
   ~ limitations under the License.
   ~
   ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -32,16 +33,16 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_7_material" />
-
-        <include layout="@layout/cpp_simple_button_8_material" />
-
-        <include layout="@layout/cpp_simple_button_9_material" />
-
-        <include layout="@layout/cpp_simple_button_multiplication_material" />
-
         <include layout="@layout/cpp_simple_button_percent_material" />
 
+        <include layout="@layout/cpp_simple_button_left_material" />
+
+        <include layout="@layout/cpp_simple_button_right_material" />
+
+        <include layout="@layout/cpp_simple_button_settings_material" />
+
+        <include layout="@layout/cpp_simple_button_erase_material" />
+
         <include layout="@layout/cpp_simple_button_clear_material" />
 
     </LinearLayout>
@@ -51,35 +52,16 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_4_material" />
+        <include layout="@layout/cpp_simple_button_functions_material" />
 
-        <include layout="@layout/cpp_simple_button_5_material" />
+        <include layout="@layout/cpp_simple_button_7_material" />
 
-        <include layout="@layout/cpp_simple_button_6_material" />
+        <include layout="@layout/cpp_simple_button_8_material" />
+
+        <include layout="@layout/cpp_simple_button_9_material" />
 
         <include layout="@layout/cpp_simple_button_division_material" />
 
-        <include layout="@layout/cpp_simple_button_power_material" />
-
-        <include layout="@layout/cpp_simple_button_erase_material" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_1_material" />
-
-        <include layout="@layout/cpp_simple_button_2_material" />
-
-        <include layout="@layout/cpp_simple_button_3_material" />
-
-        <include layout="@layout/cpp_simple_button_plus_material" />
-
-        <include layout="@layout/cpp_simple_button_settings_material" />
-
         <include layout="@layout/cpp_simple_button_copy_material" />
 
     </LinearLayout>
@@ -89,36 +71,54 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_round_brackets_material" />
+        <include layout="@layout/cpp_simple_button_vars_material" />
 
-        <include layout="@layout/cpp_simple_button_0_material" />
+        <include layout="@layout/cpp_simple_button_4_material" />
 
-        <include layout="@layout/cpp_simple_button_dot_material" />
+        <include layout="@layout/cpp_simple_button_5_material" />
 
-        <include layout="@layout/cpp_simple_button_minus_material" />
+        <include layout="@layout/cpp_simple_button_6_material" />
 
-        <include layout="@layout/cpp_simple_button_app_material" />
+        <include layout="@layout/cpp_simple_button_multiplication_material" />
 
         <include layout="@layout/cpp_simple_button_paste_material" />
 
     </LinearLayout>
 
-
     <LinearLayout
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_left_material" />
-
-        <include layout="@layout/cpp_simple_button_right_material" />
-
-        <include layout="@layout/cpp_simple_button_vars_material" />
-
-        <include layout="@layout/cpp_simple_button_functions_material" />
-
         <include layout="@layout/cpp_simple_button_operators_material" />
 
+        <include layout="@layout/cpp_simple_button_1_material" />
+
+        <include layout="@layout/cpp_simple_button_2_material" />
+
+        <include layout="@layout/cpp_simple_button_3_material" />
+
+        <include layout="@layout/cpp_simple_button_minus_material" />
+
+        <include layout="@layout/cpp_simple_button_app_material" />
+
+    </LinearLayout>
+
+    <LinearLayout
+        a:layout_width="match_parent"
+        a:layout_height="0dp"
+        a:layout_weight="1">
+
+        <include layout="@layout/cpp_simple_button_power_material" />
+
+        <include layout="@layout/cpp_simple_button_0_material" />
+
+        <include layout="@layout/cpp_simple_button_dot_material" />
+
+        <include layout="@layout/cpp_simple_button_round_brackets_material" />
+
+        <include layout="@layout/cpp_simple_button_plus_material" />
+
         <include layout="@layout/cpp_simple_button_history_material" />
 
     </LinearLayout>
diff --git a/app/src/main/res/layout/widget_keyboard_material_light.xml b/app/src/main/res/layout/widget_keyboard_material_light.xml
index cc40e6bc..445c9d70 100644
--- a/app/src/main/res/layout/widget_keyboard_material_light.xml
+++ b/app/src/main/res/layout/widget_keyboard_material_light.xml
@@ -12,7 +12,8 @@
   ~ Unless required by applicable law or agreed to in writing, software
   ~ distributed under the License is distributed on an "AS IS" BASIS,
   ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
+  ~ See the Licens        <item name="android:background">@drawable/material_button_light_darker</item>
+e for the specific language governing permissions and
   ~ limitations under the License.
   ~
   ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -32,16 +33,16 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_7_material_light" />
-
-        <include layout="@layout/cpp_simple_button_8_material_light" />
-
-        <include layout="@layout/cpp_simple_button_9_material_light" />
-
-        <include layout="@layout/cpp_simple_button_multiplication_material_light" />
-
         <include layout="@layout/cpp_simple_button_percent_material_light" />
 
+        <include layout="@layout/cpp_simple_button_left_material_light" />
+
+        <include layout="@layout/cpp_simple_button_right_material_light" />
+
+        <include layout="@layout/cpp_simple_button_settings_material_light" />
+
+        <include layout="@layout/cpp_simple_button_erase_material_light" />
+
         <include layout="@layout/cpp_simple_button_clear_material_light" />
 
     </LinearLayout>
@@ -51,35 +52,16 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_4_material_light" />
+        <include layout="@layout/cpp_simple_button_functions_material_light" />
 
-        <include layout="@layout/cpp_simple_button_5_material_light" />
+        <include layout="@layout/cpp_simple_button_7_material_light" />
 
-        <include layout="@layout/cpp_simple_button_6_material_light" />
+        <include layout="@layout/cpp_simple_button_8_material_light" />
+
+        <include layout="@layout/cpp_simple_button_9_material_light" />
 
         <include layout="@layout/cpp_simple_button_division_material_light" />
 
-        <include layout="@layout/cpp_simple_button_power_material_light" />
-
-        <include layout="@layout/cpp_simple_button_erase_material_light" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        a:layout_width="match_parent"
-        a:layout_height="0dp"
-        a:layout_weight="1">
-
-        <include layout="@layout/cpp_simple_button_1_material_light" />
-
-        <include layout="@layout/cpp_simple_button_2_material_light" />
-
-        <include layout="@layout/cpp_simple_button_3_material_light" />
-
-        <include layout="@layout/cpp_simple_button_plus_material_light" />
-
-        <include layout="@layout/cpp_simple_button_settings_material_light" />
-
         <include layout="@layout/cpp_simple_button_copy_material_light" />
 
     </LinearLayout>
@@ -89,36 +71,54 @@
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_round_brackets_material_light" />
+        <include layout="@layout/cpp_simple_button_vars_material_light" />
 
-        <include layout="@layout/cpp_simple_button_0_material_light" />
+        <include layout="@layout/cpp_simple_button_4_material_light" />
 
-        <include layout="@layout/cpp_simple_button_dot_material_light" />
+        <include layout="@layout/cpp_simple_button_5_material_light" />
 
-        <include layout="@layout/cpp_simple_button_minus_material_light" />
+        <include layout="@layout/cpp_simple_button_6_material_light" />
 
-        <include layout="@layout/cpp_simple_button_app_material_light" />
+        <include layout="@layout/cpp_simple_button_multiplication_material_light" />
 
         <include layout="@layout/cpp_simple_button_paste_material_light" />
 
     </LinearLayout>
 
-
     <LinearLayout
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1">
 
-        <include layout="@layout/cpp_simple_button_left_material_light" />
-
-        <include layout="@layout/cpp_simple_button_right_material_light" />
-
-        <include layout="@layout/cpp_simple_button_vars_material_light" />
-
-        <include layout="@layout/cpp_simple_button_functions_material_light" />
-
         <include layout="@layout/cpp_simple_button_operators_material_light" />
 
+        <include layout="@layout/cpp_simple_button_1_material_light" />
+
+        <include layout="@layout/cpp_simple_button_2_material_light" />
+
+        <include layout="@layout/cpp_simple_button_3_material_light" />
+
+        <include layout="@layout/cpp_simple_button_minus_material_light" />
+
+        <include layout="@layout/cpp_simple_button_app_material_light" />
+
+    </LinearLayout>
+
+    <LinearLayout
+        a:layout_width="match_parent"
+        a:layout_height="0dp"
+        a:layout_weight="1">
+
+        <include layout="@layout/cpp_simple_button_power_material_light" />
+
+        <include layout="@layout/cpp_simple_button_0_material_light" />
+
+        <include layout="@layout/cpp_simple_button_dot_material_light" />
+
+        <include layout="@layout/cpp_simple_button_round_brackets_material_light" />
+
+        <include layout="@layout/cpp_simple_button_plus_material_light" />
+
         <include layout="@layout/cpp_simple_button_history_material_light" />
 
     </LinearLayout>
diff --git a/app/src/main/res/values/theme_material.xml b/app/src/main/res/values/theme_material.xml
index fd8d299f..6d2c404d 100644
--- a/app/src/main/res/values/theme_material.xml
+++ b/app/src/main/res/values/theme_material.xml
@@ -56,10 +56,22 @@
         <item name="android:textSize">@dimen/cpp_widget_keyboard_button_text_size</item>
     </style>
 
+    <style name="CppKeyboardButton.Material.Simple.NoBg" parent="CppKeyboardButton.Material.Simple.Control">
+        <item name="android:background">@drawable/widget_button_no_bg</item>
+    </style>
+
+    <style name="CppKeyboardButton.Material.Simple.Control.Highlighted" parent="CppKeyboardButton.Material.Simple.Control">
+        <item name="android:background">@drawable/material_button_light</item>
+    </style>
+
     <style name="CppKeyboardButton.Material.Simple.Control.Image" parent="CppKeyboardButton.Material.Control">
         <item name="android:padding">@dimen/cpp_keyboard_simple_image_button_padding</item>
     </style>
 
+    <style name="CppKeyboardButton.Material.Simple.Control.Image.Highlighted" parent="CppKeyboardButton.Material.Simple.Control.Image">
+        <item name="android:background">@drawable/material_blue_button_lighter</item>
+    </style>
+
     <style name="CppKeyboardButton.Material.Simple.Operation" parent="CppKeyboardButton.Material.Operation">
         <item name="android:textSize">@dimen/cpp_widget_keyboard_button_text_size</item>
     </style>
diff --git a/app/src/main/res/values/theme_material_light.xml b/app/src/main/res/values/theme_material_light.xml
index e9a3affd..9f2d1e42 100644
--- a/app/src/main/res/values/theme_material_light.xml
+++ b/app/src/main/res/values/theme_material_light.xml
@@ -57,10 +57,23 @@
         <item name="android:textSize">@dimen/cpp_widget_keyboard_button_text_size</item>
     </style>
 
+    <style name="CppKeyboardButton.Material.Light.Simple.Control.Highlighted" parent="CppKeyboardButton.Material.Light.Simple.Control">
+        <item name="android:background">@drawable/material_button_light_darker</item>
+    </style>
+
+    <style name="CppKeyboardButton.Material.Light.Simple.NoBg" parent="CppKeyboardButton.Material.Light.Control">
+        <item name="android:background">@drawable/widget_button_no_bg_light</item>
+        <item name="android:textColor">@color/cpp_text_inverse</item>
+    </style>
+
     <style name="CppKeyboardButton.Material.Light.Simple.Control.Image" parent="CppKeyboardButton.Material.Light.Control">
         <item name="android:padding">@dimen/cpp_keyboard_simple_image_button_padding</item>
     </style>
 
+    <style name="CppKeyboardButton.Material.Light.Simple.Control.Image.Highlighted" parent="CppKeyboardButton.Material.Light.Simple.Control.Image">
+        <item name="android:background">@drawable/material_button_light_primary_darker</item>
+    </style>
+
     <style name="CppKeyboardButton.Material.Light.Simple.Operation" parent="CppKeyboardButton.Material.Light.Operation">
         <item name="android:textSize">@dimen/cpp_widget_keyboard_button_text_size</item>
     </style>
diff --git a/app/src/main/res/values/theme_metro_blue.xml b/app/src/main/res/values/theme_metro_blue.xml
index b9d29c4a..4f006d40 100644
--- a/app/src/main/res/values/theme_metro_blue.xml
+++ b/app/src/main/res/values/theme_metro_blue.xml
@@ -53,11 +53,20 @@
         <item name="android:background">@drawable/metro_widget_button_light</item>
     </style>
 
+    <style name="CppKeyboardButton.Metro.Simple.NoBg" parent="CppKeyboardButton.Metro.Simple.Control">
+        <item name="android:background">@drawable/widget_button_no_bg</item>
+    </style>
+
     <style name="CppKeyboardButton.Metro.Simple.Operation" parent="CppKeyboardButton.Metro.Blue.Operation">
         <item name="android:textSize">@dimen/cpp_widget_keyboard_button_text_size</item>
         <item name="android:background">@drawable/metro_widget_button</item>
     </style>
 
+    <style name="CppKeyboardButton.Metro.Simple.Operation.Image" parent="CppKeyboardButton.Metro.Simple.Operation">
+        <item name="android:background">@drawable/metro_widget_button</item>
+        <item name="android:padding">@dimen/cpp_keyboard_simple_image_button_padding</item>
+    </style>
+
     <style name="CppKeyboardButton.Metro.Simple.Control.Image" parent="CppKeyboardButton.Metro.Blue.Control">
         <item name="android:background">@drawable/metro_widget_button_light</item>
         <item name="android:padding">@dimen/cpp_keyboard_simple_image_button_padding</item>