diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index aaab359..016c75c 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -13,7 +13,7 @@
         android:networkSecurityConfig="@xml/network_security_config"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/Theme.Acanthus"
+        android:theme="@style/Theme.Acanthus.Dark"
         android:usesCleartextTraffic="true">
         <activity android:name=".views.animation.AnimationActivity"></activity>
         <activity android:name=".views.animation_detail.AnimationDetailActivity"></activity>
diff --git a/app/src/main/java/org/ntlab/acanthus_client/views/MainActivity.java b/app/src/main/java/org/ntlab/acanthus_client/views/MainActivity.java
index 3a989e7..439934e 100644
--- a/app/src/main/java/org/ntlab/acanthus_client/views/MainActivity.java
+++ b/app/src/main/java/org/ntlab/acanthus_client/views/MainActivity.java
@@ -1,10 +1,6 @@
 package org.ntlab.acanthus_client.views;
 
-import android.content.Intent;
-import android.content.SharedPreferences;
 import android.os.Bundle;
-import android.view.View;
-import android.widget.Button;
 
 import com.google.android.material.bottomnavigation.BottomNavigationView;
 
@@ -18,32 +14,18 @@
 import androidx.navigation.ui.NavigationUI;
 
 
-public class MainActivity extends AppCompatActivity implements View.OnClickListener {
+public class MainActivity extends AppCompatActivity {
 
     private ActivityMainBinding binding;
 
-    private Button mBtDefault, mBtDark;
-
-    private SharedPreferences mPreferences;
-    private SharedPreferences.Editor mEditor;
-
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         binding = ActivityMainBinding.inflate(getLayoutInflater());
-        mPreferences = getSharedPreferences("themeData", MODE_PRIVATE);
-        setTheme( mPreferences.getInt("theme", R.style.Theme_Acanthus) );
+        setTheme(R.style.Theme_Acanthus_Dark);
         setContentView(binding.getRoot());
 
-        mBtDefault  = (Button)findViewById(R.id.bt_default);
-        mBtDark = (Button)findViewById(R.id.bt_dark);
-
-        mBtDefault.setOnClickListener(this);
-        mBtDark.setOnClickListener(this);
-
-        mEditor = mPreferences.edit();
-
         BottomNavigationView navView = findViewById(R.id.nav_view);
         // Passing each menu ID as a set of Ids because each
         // menu should be considered as top level destinations.
@@ -55,21 +37,4 @@
         NavigationUI.setupWithNavController(binding.navView, navController);
     }
 
-    @Override
-    public void onClick(View view) {
-        switch (view.getId()) {
-            case R.id.bt_default: {
-                mEditor.putInt("theme", R.style.Theme_Acanthus);
-                break;
-            }
-            case R.id.bt_dark: {
-                mEditor.putInt("theme", R.style.Theme_Acanthus_Dark);
-                break;
-            }
-        }
-        mEditor.commit();
-        finish();
-        startActivity( new Intent( this, MainActivity.class ));
-    }
-
 }
\ No newline at end of file
diff --git a/app/src/main/res/values/themes.xml b/app/src/main/res/values/themes.xml
index 24ede86..4888220 100644
--- a/app/src/main/res/values/themes.xml
+++ b/app/src/main/res/values/themes.xml
@@ -1,6 +1,8 @@
 <resources>
     <!-- Base application theme. -->
     <style name="Theme.Acanthus" parent="Theme.AppCompat.Light"/>
-    <style name="Theme.Acanthus.Dark" parent="Theme.AppCompat"/>
+    <style name="Theme.Acanthus.Dark" parent="Theme.AppCompat">
+        <item name="android:navigationBarColor">@color/white</item>
+    </style>
     <style name="AppTheme.NoTitleBar" parent="Theme.AppCompat.NoActionBar"/>
 </resources>
\ No newline at end of file