diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index 88ea3aa..3cc336b 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -1,6 +1,22 @@
 <component name="ProjectCodeStyleConfiguration">
   <code_scheme name="Project" version="173">
     <JetCodeStyleSettings>
+      <option name="PACKAGES_TO_USE_STAR_IMPORTS">
+        <value>
+          <package name="java.util" alias="false" withSubpackages="false" />
+          <package name="kotlinx.android.synthetic" alias="false" withSubpackages="true" />
+          <package name="io.ktor" alias="false" withSubpackages="true" />
+        </value>
+      </option>
+      <option name="PACKAGES_IMPORT_LAYOUT">
+        <value>
+          <package name="" alias="false" withSubpackages="true" />
+          <package name="java" alias="false" withSubpackages="true" />
+          <package name="javax" alias="false" withSubpackages="true" />
+          <package name="kotlin" alias="false" withSubpackages="true" />
+          <package name="" alias="true" withSubpackages="true" />
+        </value>
+      </option>
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
     </JetCodeStyleSettings>
     <codeStyleSettings language="XML">
diff --git a/.idea/dictionaries/fabian.xml b/.idea/dictionaries/fabian.xml
index 92342ab..0fad81e 100644
--- a/.idea/dictionaries/fabian.xml
+++ b/.idea/dictionaries/fabian.xml
@@ -1,7 +1,9 @@
 <component name="ProjectDictionaryState">
   <dictionary name="fabian">
     <words>
+      <w>checkmark</w>
       <w>tichu</w>
+      <w>tichucounter</w>
       <w>zobrist</w>
     </words>
   </dictionary>
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 7bfef59..ae2bfea 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,44 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="NullableNotNullManager">
+    <option name="myDefaultNullable" value="androidx.annotation.Nullable" />
+    <option name="myDefaultNotNull" value="androidx.annotation.NonNull" />
+    <option name="myNullables">
+      <value>
+        <list size="12">
+          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
+          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
+          <item index="2" class="java.lang.String" itemvalue="javax.annotation.CheckForNull" />
+          <item index="3" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
+          <item index="4" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
+          <item index="5" class="java.lang.String" itemvalue="androidx.annotation.Nullable" />
+          <item index="6" class="java.lang.String" itemvalue="android.annotation.Nullable" />
+          <item index="7" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNullable" />
+          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
+          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
+          <item index="10" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
+          <item index="11" class="java.lang.String" itemvalue="com.android.annotations.Nullable" />
+        </list>
+      </value>
+    </option>
+    <option name="myNotNulls">
+      <value>
+        <list size="11">
+          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
+          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
+          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
+          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
+          <item index="4" class="java.lang.String" itemvalue="androidx.annotation.NonNull" />
+          <item index="5" class="java.lang.String" itemvalue="android.annotation.NonNull" />
+          <item index="6" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNonNull" />
+          <item index="7" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.NonNull" />
+          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullDecl" />
+          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullType" />
+          <item index="10" class="java.lang.String" itemvalue="com.android.annotations.NonNull" />
+        </list>
+      </value>
+    </option>
+  </component>
   <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
diff --git a/app/build.gradle b/app/build.gradle
index d57e2cd..335d9cc 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -34,12 +34,12 @@ android {
 dependencies {
     implementation fileTree(dir: "libs", include: ["*.jar"])
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-    implementation 'androidx.core:core-ktx:1.1.0'
-    implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'com.google.android.material:material:1.0.0'
+    implementation 'androidx.core:core-ktx:1.3.1'
+    implementation 'androidx.appcompat:appcompat:1.2.0'
+    implementation 'com.google.android.material:material:1.2.0'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
-    implementation 'androidx.navigation:navigation-fragment-ktx:2.1.0'
-    implementation 'androidx.navigation:navigation-ui-ktx:2.1.0'
+    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.0'
+    implementation 'androidx.navigation:navigation-ui-ktx:2.3.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
diff --git a/app/src/main/java/me/zobrist/tichucounter/History.kt b/app/src/main/java/me/zobrist/tichucounter/History.kt
index 556408c..9f2cd3a 100644
--- a/app/src/main/java/me/zobrist/tichucounter/History.kt
+++ b/app/src/main/java/me/zobrist/tichucounter/History.kt
@@ -1,3 +1,5 @@
+@file:Suppress("unused")
+
 package me.zobrist.tichucounter
 
 import android.os.Parcel
@@ -6,7 +8,7 @@ import android.os.Parcelable
 class History() : Parcelable {
     private var scores: ArrayList<Round> = ArrayList()
 
-    constructor(parcel: Parcel) : this(){
+    constructor(parcel: Parcel) : this() {
         scores = parcel.readSerializable() as ArrayList<Round>
     }
 
diff --git a/app/src/main/java/me/zobrist/tichucounter/MainActivity.kt b/app/src/main/java/me/zobrist/tichucounter/MainActivity.kt
index c7b9b2f..ba064e1 100644
--- a/app/src/main/java/me/zobrist/tichucounter/MainActivity.kt
+++ b/app/src/main/java/me/zobrist/tichucounter/MainActivity.kt
@@ -237,7 +237,7 @@ class MainActivity : AppCompatActivity() {
                 inputTeamA.text.clear()
                 inputTeamB.text.clear()
 
-                scrolViewHistory.fullScroll(ScrollView.FOCUS_DOWN)
+                scrollViewHistory.fullScroll(ScrollView.FOCUS_DOWN)
 
             }
         }
diff --git a/app/src/main/java/me/zobrist/tichucounter/Round.kt b/app/src/main/java/me/zobrist/tichucounter/Round.kt
index 88fc5d4..fad6b61 100644
--- a/app/src/main/java/me/zobrist/tichucounter/Round.kt
+++ b/app/src/main/java/me/zobrist/tichucounter/Round.kt
@@ -14,8 +14,6 @@ class Round() {
         }
     }
 
-    constructor(score: String, isScoreA: Boolean): this(score.toInt(), isScoreA)
-
     constructor(scoreA: Int, scoreB: Int) : this() {
         this.scoreA = scoreA
         this.scoreB = scoreB
diff --git a/app/src/main/res/layout-land/content_main.xml b/app/src/main/res/layout-land/content_main.xml
index 3171189..0a2440a 100644
--- a/app/src/main/res/layout-land/content_main.xml
+++ b/app/src/main/res/layout-land/content_main.xml
@@ -75,7 +75,7 @@
         </LinearLayout>
 
         <ScrollView
-            android:id="@+id/scrolViewHistory"
+            android:id="@+id/scrollViewHistory"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_marginTop="16dp">
@@ -145,12 +145,14 @@
 
         <LinearLayout
             android:id="@+id/ButtonRow1"
+            style="?android:attr/buttonBarStyle"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="horizontal">
 
             <Button
                 android:id="@+id/button1"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -158,6 +160,7 @@
 
             <Button
                 android:id="@+id/button2"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -165,6 +168,7 @@
 
             <Button
                 android:id="@+id/button3"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -172,6 +176,7 @@
 
             <Button
                 android:id="@+id/buttonAdd100"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -180,12 +185,14 @@
 
         <LinearLayout
             android:id="@+id/ButtonRow2"
+            style="?android:attr/buttonBarStyle"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="horizontal">
 
             <Button
                 android:id="@+id/button4"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -193,6 +200,7 @@
 
             <Button
                 android:id="@+id/button5"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -200,6 +208,7 @@
 
             <Button
                 android:id="@+id/button6"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -207,6 +216,7 @@
 
             <Button
                 android:id="@+id/buttonSub100"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -215,12 +225,14 @@
 
         <LinearLayout
             android:id="@+id/ButtonRow3"
+            style="?android:attr/buttonBarStyle"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="horizontal">
 
             <Button
                 android:id="@+id/button7"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -228,6 +240,7 @@
 
             <Button
                 android:id="@+id/button8"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -235,6 +248,7 @@
 
             <Button
                 android:id="@+id/button9"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
@@ -242,6 +256,7 @@
 
             <ImageButton
                 android:id="@+id/buttonBack"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="match_parent"
                 android:layout_weight="1"
@@ -255,12 +270,14 @@
 
         <LinearLayout
             android:id="@+id/ButtonRow4"
+            style="?android:attr/buttonBarStyle"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="horizontal">
 
             <Button
                 android:id="@+id/buttonInv"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1.0"
@@ -268,6 +285,7 @@
 
             <Button
                 android:id="@+id/button0"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1.0"
@@ -280,6 +298,7 @@
 
             <ImageButton
                 android:id="@+id/submit"
+                style='style="?android:attr/buttonBarButtonStyle'
                 android:layout_width="0dp"
                 android:layout_height="match_parent"
                 android:layout_weight="1.0"
diff --git a/app/src/main/res/layout/content_main.xml b/app/src/main/res/layout/content_main.xml
index fef7c44..844ea9c 100644
--- a/app/src/main/res/layout/content_main.xml
+++ b/app/src/main/res/layout/content_main.xml
@@ -71,10 +71,10 @@
         android:layout_width="match_parent"
         android:layout_height="1dp"
         android:background="?android:attr/listDivider"
-        app:layout_constraintBottom_toBottomOf="@+id/scrolViewHistory" />
+        app:layout_constraintBottom_toBottomOf="@+id/scrollViewHistory" />
 
     <ScrollView
-        android:id="@+id/scrolViewHistory"
+        android:id="@+id/scrollViewHistory"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_marginTop="16dp"
@@ -144,6 +144,7 @@
 
     <LinearLayout
         android:id="@+id/ButtonRow1"
+        style="?android:attr/buttonBarStyle"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:orientation="horizontal"
@@ -151,6 +152,7 @@
 
         <Button
             android:id="@+id/button1"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -158,6 +160,7 @@
 
         <Button
             android:id="@+id/button2"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -165,6 +168,7 @@
 
         <Button
             android:id="@+id/button3"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -172,6 +176,7 @@
 
         <Button
             android:id="@+id/buttonAdd100"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -180,6 +185,7 @@
 
     <LinearLayout
         android:id="@+id/ButtonRow2"
+        style="?android:attr/buttonBarStyle"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:orientation="horizontal"
@@ -187,6 +193,7 @@
 
         <Button
             android:id="@+id/button4"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -194,6 +201,7 @@
 
         <Button
             android:id="@+id/button5"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -201,6 +209,7 @@
 
         <Button
             android:id="@+id/button6"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -208,6 +217,7 @@
 
         <Button
             android:id="@+id/buttonSub100"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -216,6 +226,7 @@
 
     <LinearLayout
         android:id="@+id/ButtonRow3"
+        style="?android:attr/buttonBarStyle"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:orientation="horizontal"
@@ -223,6 +234,7 @@
 
         <Button
             android:id="@+id/button7"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -230,6 +242,7 @@
 
         <Button
             android:id="@+id/button8"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -237,6 +250,7 @@
 
         <Button
             android:id="@+id/button9"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
@@ -244,6 +258,7 @@
 
         <ImageButton
             android:id="@+id/buttonBack"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="match_parent"
             android:layout_weight="1"
@@ -257,6 +272,7 @@
 
     <LinearLayout
         android:id="@+id/ButtonRow4"
+        style="?android:attr/buttonBarStyle"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:orientation="horizontal"
@@ -266,6 +282,7 @@
 
         <Button
             android:id="@+id/buttonInv"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1.0"
@@ -273,6 +290,7 @@
 
         <Button
             android:id="@+id/button0"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1.0"
@@ -285,6 +303,7 @@
 
         <ImageButton
             android:id="@+id/submit"
+            style='style="?android:attr/buttonBarButtonStyle'
             android:layout_width="0dp"
             android:layout_height="match_parent"
             android:layout_weight="1.0"