Created landscape layout for activity_main

app/src/main/res/layout-land/activity_main.xml

+<?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"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="@drawable/gradient">
+
+    <TextView
+        android:id="@+id/tv_how_many_digits"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="16dp"
+        android:layout_marginEnd="16dp"
+        android:gravity="center"
+        android:text="@string/how_many_digits"
+        android:textAppearance="@style/TextAppearance.MaterialComponents.Headline4"
+        android:textColor="@android:color/white"
+        app:layout_constraintBottom_toTopOf="@+id/layout_num_digits"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_chainStyle="packed" />
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:id="@+id/layout_num_digits"
+        android:layout_width="0dp"
+        android:layout_height="100dp"
+        android:layout_marginTop="16dp"
+        app:layout_constraintEnd_toEndOf="@+id/tv_how_many_digits"
+        app:layout_constraintStart_toStartOf="@+id/tv_how_many_digits"
+        app:layout_constraintTop_toBottomOf="@+id/tv_how_many_digits"
+        app:layout_constraintBottom_toTopOf="@+id/seek_bar">
+
+        <com.google.android.material.card.MaterialCardView
+            android:id="@+id/card_2_digits"
+            style="@style/MyCard"
+            android:foreground="?android:attr/selectableItemBackground"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toStartOf="@+id/card_3_digits"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <TextView
+                style="@style/AnswerCardText"
+                android:text="@string/number_digits_2" />
+        </com.google.android.material.card.MaterialCardView>
+
+        <com.google.android.material.card.MaterialCardView
+            android:id="@+id/card_3_digits"
+            style="@style/MyCard"
+            android:foreground="?android:attr/selectableItemBackground"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toStartOf="@+id/card_4_digits"
+            app:layout_constraintStart_toEndOf="@+id/card_2_digits"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <TextView
+                style="@style/AnswerCardText"
+                android:text="@string/number_digits_3" />
+        </com.google.android.material.card.MaterialCardView>
+
+        <com.google.android.material.card.MaterialCardView
+            android:id="@+id/card_4_digits"
+            style="@style/MyCard"
+            android:foreground="?android:attr/selectableItemBackground"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toEndOf="@id/card_3_digits"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <TextView
+                style="@style/AnswerCardText"
+                android:text="@string/number_digits_4" />
+        </com.google.android.material.card.MaterialCardView>
+    </androidx.constraintlayout.widget.ConstraintLayout>
+
+    <com.crystal.crystalrangeseekbar.widgets.CrystalSeekbar
+        android:id="@+id/seek_bar"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="16dp"
+        app:bar_color="@android:color/white"
+        app:bar_highlight_color="@color/colorPrimary"
+        app:corner_radius="10"
+        app:data_type="_integer"
+        app:layout_constraintEnd_toEndOf="@+id/layout_num_digits"
+        app:layout_constraintStart_toStartOf="@+id/layout_num_digits"
+        app:layout_constraintTop_toBottomOf="@+id/layout_num_digits"
+        app:layout_constraintBottom_toTopOf="@+id/seek_bar_value"
+        app:left_thumb_color="@android:color/white"
+        app:left_thumb_color_pressed="@color/colorPrimary"
+        app:max_value="10"
+        app:min_value="2" />
+
+    <TextView
+        android:id="@+id/seek_bar_value"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:text="@string/time_to_solve"
+        android:textAppearance="@style/TextAppearance.MaterialComponents.Caption"
+        android:textColor="@android:color/white"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/layout_num_digits"
+        app:layout_constraintTop_toBottomOf="@+id/seek_bar" />
+
+    <com.google.android.material.button.MaterialButton
+        android:id="@+id/btn_play"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="8dp"
+        android:layout_marginBottom="8dp"
+        android:text="@string/play"
+        app:backgroundTint="@color/colorPrimary"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file

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

@@ -10,7 +10,6 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
-        android:layout_marginTop="16dp"
         android:layout_marginEnd="16dp"
         android:gravity="center"
         android:text="@string/how_many_digits"