Add dark mode support and improve language handling in SettingsActivity

- Refactored color constants to support both light and dark modes.
- Implemented a toggle for dark mode in SettingsActivity.
- Updated language selection functionality to correctly display "Español".
- Enhanced prayer management in ExtrasActivity with a detailed view.
- Added new styles for dark mode in styles.xml.

app/src/main/java/com/b

@@ -0,0 +1,478 @@
+package com.bibliadiaria.app;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.graphics.Color;
+import android.graphics.Typeface;
+import android.graphics.drawable.GradientDrawable;
+import android.os.Build;
+import android.os.Bundle;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.LinearLayout;
+import android.widget.ScrollView;
+import android.widget.Switch;
+import android.widget.TextView;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class SettingsActivity extends Activity {
+    // Light mode colors
+    private static final int COLOR_BG_LIGHT = Color.rgb(247, 248, 246);
+    private static final int COLOR_CARD_LIGHT = Color.WHITE;
+    private static final int COLOR_INK_LIGHT = Color.rgb(25, 31, 31);
+    private static final int COLOR_MUTED_LIGHT = Color.rgb(91, 99, 98);
+    private static final int COLOR_STROKE_LIGHT = Color.rgb(219, 226, 222);
+    private static final int COLOR_CARD_STROKE_LIGHT = Color.rgb(229, 232, 230);
+
+    // Dark mode colors
+    private static final int COLOR_BG_DARK = Color.rgb(26, 28, 30);
+    private static final int COLOR_CARD_DARK = Color.rgb(38, 41, 44);
+    private static final int COLOR_INK_DARK = Color.rgb(224, 226, 219);
+    private static final int COLOR_MUTED_DARK = Color.rgb(158, 163, 160);
+    private static final int COLOR_STROKE_DARK = Color.rgb(48, 52, 55);
+    private static final int COLOR_CARD_STROKE_DARK = Color.rgb(58, 62, 65);
+
+    private static final int COLOR_ACCENT = Color.rgb(0, 107, 90);
+    private static final int COLOR_WARM = Color.rgb(217, 75, 61);
+
+    private ExecutorService executor;
+    private TextView statusText;
+    private TextView installedVersionText;
+    private TextView checkButton;
+    private TextView downloadButton;
+    private TextView voiceSubtitleText;
+    private TextView voiceButton;
+    private UpdateManager.UpdateInfo latestInfo;
+    private boolean isEnglish;
+    private boolean isDarkMode;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        isEnglish = UpdateManager.isEnglish(this);
+        isDarkMode = UpdateManager.isDarkMode(this);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            getWindow().setStatusBarColor(bg());
+            getWindow().setNavigationBarColor(bg());
+        }
+
+        executor = Executors.newSingleThreadExecutor();
+        setContentView(createScreen());
+        updateInstalledVersionText();
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        if (executor != null) {
+            executor.shutdownNow();
+        }
+    }
+
+    private int bg() { return isDarkMode ? COLOR_BG_DARK : COLOR_BG_LIGHT; }
+    private int card() { return isDarkMode ? COLOR_CARD_DARK : COLOR_CARD_LIGHT; }
+    private int ink() { return isDarkMode ? COLOR_INK_DARK : COLOR_INK_LIGHT; }
+    private int muted() { return isDarkMode ? COLOR_MUTED_DARK : COLOR_MUTED_LIGHT; }
+    private int stroke() { return isDarkMode ? COLOR_STROKE_DARK : COLOR_STROKE_LIGHT; }
+    private int cardStroke() { return isDarkMode ? COLOR_CARD_STROKE_DARK : COLOR_CARD_STROKE_LIGHT; }
+
+    private View createScreen() {
+        FrameLayout root = new FrameLayout(this);
+        root.setBackgroundColor(bg());
+
+        ScrollView scrollView = new ScrollView(this);
+        scrollView.setFillViewport(true);
+        scrollView.setClipToPadding(false);
+
+        LinearLayout content = new LinearLayout(this);
+        content.setOrientation(LinearLayout.VERTICAL);
+        content.setPadding(dp(20), dp(28), dp(20), dp(28));
+        scrollView.addView(content, new ScrollView.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        content.addView(createTopBar());
+
+        TextView title = textView("Settings", 34, ink(), Typeface.BOLD);
+        title.setIncludeFontPadding(false);
+        LinearLayout.LayoutParams titleParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        titleParams.setMargins(0, dp(18), 0, dp(18));
+        content.addView(title, titleParams);
+
+        content.addView(createDarkModeCard());
+        content.addView(createLanguageCard());
+        content.addView(createVoiceCard());
+        content.addView(createVersionCard());
+
+        checkButton = actionButton(isEnglish ? "Check now" : "Comprobar", COLOR_ACCENT, Color.WHITE);
+        checkButton.setOnClickListener(view -> checkForUpdate());
+        LinearLayout.LayoutParams checkParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                dp(46)
+        );
+        checkParams.setMargins(0, dp(16), 0, 0);
+        content.addView(checkButton, checkParams);
+
+        downloadButton = actionButton("Download latest APK", COLOR_WARM, Color.WHITE);
+        downloadButton.setVisibility(View.GONE);
+        downloadButton.setOnClickListener(view -> {
+            String url = latestInfo == null ? UpdateManager.APK_URL : latestInfo.apkUrl;
+            UpdateManager.openDownload(this, url);
+        });
+        LinearLayout.LayoutParams downloadParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                dp(46)
+        );
+        downloadParams.setMargins(0, dp(10), 0, 0);
+        content.addView(downloadButton, downloadParams);
+
+        root.addView(scrollView, new FrameLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT
+        ));
+
+        root.setOnApplyWindowInsetsListener((view, insets) -> {
+            content.setPadding(
+                    dp(20),
+                    dp(28) + insets.getSystemWindowInsetTop(),
+                    dp(20),
+                    dp(28) + insets.getSystemWindowInsetBottom()
+            );
+            return insets;
+        });
+        root.requestApplyInsets();
+
+        return root;
+    }
+
+    private View createTopBar() {
+        LinearLayout topBar = new LinearLayout(this);
+        topBar.setOrientation(LinearLayout.HORIZONTAL);
+        topBar.setGravity(Gravity.CENTER_VERTICAL);
+
+        TextView label = textView("APP", 12, COLOR_ACCENT, Typeface.BOLD);
+        topBar.addView(label, new LinearLayout.LayoutParams(
+                0,
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                1f
+        ));
+
+        TextView back = textView(isEnglish ? "Extras" : "Extras", 15, COLOR_ACCENT, Typeface.BOLD);
+        back.setGravity(Gravity.CENTER);
+        back.setPadding(dp(14), 0, dp(14), 0);
+        back.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
+        back.setOnClickListener(view -> finish());
+        topBar.addView(back, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                dp(40)
+        ));
+
+        return topBar;
+    }
+
+    private View createDarkModeCard() {
+        LinearLayout card = createCard();
+        card.setOrientation(LinearLayout.HORIZONTAL);
+        card.setGravity(Gravity.CENTER_VERTICAL);
+
+        LinearLayout copy = new LinearLayout(this);
+        copy.setOrientation(LinearLayout.VERTICAL);
+
+        TextView title = textView(isEnglish ? "Dark Mode" : "Modo oscuro", 20, ink(), Typeface.BOLD);
+        title.setIncludeFontPadding(false);
+        copy.addView(title);
+
+        TextView subtitle = textView(
+                isEnglish ? "Use dark colors for the interface" : "Usar colores oscuros para la interfaz",
+                14, muted(), Typeface.NORMAL);
+        LinearLayout.LayoutParams subtitleParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        subtitleParams.setMargins(0, dp(6), 0, 0);
+        copy.addView(subtitle, subtitleParams);
+
+        card.addView(copy, new LinearLayout.LayoutParams(
+                0,
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                1f
+        ));
+
+        final Switch darkToggle = new Switch(this);
+        darkToggle.setChecked(isDarkMode);
+        darkToggle.setOnCheckedChangeListener((buttonView, isChecked) -> {
+            UpdateManager.setDarkMode(this, isChecked);
+            isDarkMode = isChecked;
+            recreate();
+        });
+        card.addView(darkToggle, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        return card;
+    }
+
+    private View createLanguageCard() {
+        LinearLayout card = createCard();
+        card.setOrientation(LinearLayout.HORIZONTAL);
+        card.setGravity(Gravity.CENTER_VERTICAL);
+
+        LinearLayout copy = new LinearLayout(this);
+        copy.setOrientation(LinearLayout.VERTICAL);
+
+        TextView title = textView("Language", 20, ink(), Typeface.BOLD);
+        title.setIncludeFontPadding(false);
+        copy.addView(title);
+
+        TextView subtitle = textView("Select the language for daily readings", 14, muted(), Typeface.NORMAL);
+        LinearLayout.LayoutParams subtitleParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        subtitleParams.setMargins(0, dp(6), 0, 0);
+        copy.addView(subtitle, subtitleParams);
+
+        card.addView(copy, new LinearLayout.LayoutParams(
+                0,
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                1f
+        ));
+
+        TextView langToggle = actionButton(UpdateManager.isEnglish(this) ? "English" : "Español", COLOR_ACCENT, Color.WHITE);
+        langToggle.setOnClickListener(view -> {
+            boolean current = UpdateManager.isEnglish(this);
+            UpdateManager.setEnglish(this, !current);
+            langToggle.setText(!current ? "English" : "Español");
+            updateVoiceCard();
+        });
+        card.addView(langToggle, new LinearLayout.LayoutParams(dp(100), dp(40)));
+
+        return card;
+    }
+
+    private View createVoiceCard() {
+        LinearLayout card = createCard();
+        card.setOrientation(LinearLayout.VERTICAL);
+
+        LinearLayout copy = new LinearLayout(this);
+        copy.setOrientation(LinearLayout.VERTICAL);
+
+        TextView title = textView("Voice", 20, ink(), Typeface.BOLD);
+        title.setIncludeFontPadding(false);
+        copy.addView(title);
+
+        voiceSubtitleText = textView("", 14, muted(), Typeface.NORMAL);
+        LinearLayout.LayoutParams subtitleParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        subtitleParams.setMargins(0, dp(6), 0, 0);
+        copy.addView(voiceSubtitleText, subtitleParams);
+
+        card.addView(copy, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        voiceButton = actionButton("", COLOR_ACCENT, Color.WHITE);
+        voiceButton.setOnClickListener(view -> showVoicePicker());
+        LinearLayout.LayoutParams buttonParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                dp(42)
+        );
+        buttonParams.setMargins(0, dp(12), 0, 0);
+        card.addView(voiceButton, buttonParams);
+
+        updateVoiceCard();
+        return card;
+    }
+
+    private View createVersionCard() {
+        LinearLayout card = createCard();
+        card.setOrientation(LinearLayout.VERTICAL);
+
+        TextView title = textView("Version", 20, ink(), Typeface.BOLD);
+        title.setIncludeFontPadding(false);
+        card.addView(title);
+
+        installedVersionText = textView("", 15, muted(), Typeface.BOLD);
+        LinearLayout.LayoutParams installedParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        installedParams.setMargins(0, dp(10), 0, 0);
+        card.addView(installedVersionText, installedParams);
+
+        statusText = textView("Ready to check for updates.", 15, muted(), Typeface.NORMAL);
+        statusText.setLineSpacing(dp(3), 1.1f);
+        LinearLayout.LayoutParams statusParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        statusParams.setMargins(0, dp(8), 0, 0);
+        card.addView(statusText, statusParams);
+
+        return card;
+    }
+
+    private void checkForUpdate() {
+        if (executor == null || executor.isShutdown()) {
+            return;
+        }
+
+        latestInfo = null;
+        downloadButton.setVisibility(View.GONE);
+        checkButton.setEnabled(false);
+        checkButton.setAlpha(0.62f);
+        statusText.setText("Checking for updates...");
+
+        executor.submit(() -> {
+            try {
+                UpdateManager.UpdateInfo info = UpdateManager.fetchLatestUpdate(this);
+                runOnUiThread(() -> showUpdateResult(info));
+            } catch (Exception error) {
+                runOnUiThread(() -> showUpdateError(error));
+            }
+        });
+    }
+
+    private void showUpdateResult(UpdateManager.UpdateInfo info) {
+        latestInfo = info;
+        checkButton.setEnabled(true);
+        checkButton.setAlpha(1f);
+
+        if (info.updateAvailable) {
+            String version = info.latestVersionName.isEmpty()
+                    ? String.valueOf(info.latestVersionCode)
+                    : info.latestVersionName + " (" + info.latestVersionCode + ")";
+            statusText.setText("Update available: " + version);
+            downloadButton.setVisibility(View.VISIBLE);
+            return;
+        }
+
+        statusText.setText("You are on the latest build: "
+                + info.currentVersionName + " (" + info.currentVersionCode + ")");
+    }
+
+    private void showUpdateError(Exception error) {
+        checkButton.setEnabled(true);
+        checkButton.setAlpha(1f);
+        statusText.setText("Could not check for updates. " + cleanMessage(error));
+    }
+
+    private void showVoicePicker() {
+        boolean english = UpdateManager.isEnglish(this);
+        UpdateManager.VoiceOption[] options = UpdateManager.getTtsVoiceOptions(english);
+        String[] labels = new String[options.length];
+        for (int index = 0; index < options.length; index++) {
+            labels[index] = options[index].label;
+        }
+
+        int selectedIndex = UpdateManager.getTtsVoiceIndex(
+                english,
+                UpdateManager.getTtsVoice(this, english)
+        );
+
+        new AlertDialog.Builder(this)
+                .setTitle(english ? "English voice" : "Spanish voice")
+                .setSingleChoiceItems(labels, selectedIndex, (dialog, which) -> {
+                    UpdateManager.setTtsVoice(this, english, options[which].id);
+                    updateVoiceCard();
+                    dialog.dismiss();
+                })
+                .setNegativeButton("Cancel", null)
+                .show();
+    }
+
+    private void updateVoiceCard() {
+        if (voiceSubtitleText == null || voiceButton == null) {
+            return;
+        }
+
+        boolean english = UpdateManager.isEnglish(this);
+        String voiceId = UpdateManager.getTtsVoice(this, english);
+        voiceSubtitleText.setText(english
+                ? "English voices are shown while English is selected"
+                : "Las voces en español se muestran mientras el español esté seleccionado");
+        voiceButton.setText(UpdateManager.getTtsVoiceLabel(english, voiceId));
+    }
+
+    private void updateInstalledVersionText() {
+        try {
+            installedVersionText.setText(
+                    (isEnglish ? "Installed: " : "Instalada: ")
+                            + UpdateManager.getInstalledVersionName(this)
+                            + " (" + UpdateManager.getInstalledVersionCode(this) + ")");
+        } catch (Exception error) {
+            installedVersionText.setText(isEnglish ? "Installed version unavailable." : "Versión instalada no disponible.");
+        }
+    }
+
+    private String cleanMessage(Exception error) {
+        String message = error.getMessage();
+        if (message == null || message.trim().isEmpty()) {
+            return "Unknown error.";
+        }
+        return message.trim();
+    }
+
+    private LinearLayout createCard() {
+        LinearLayout card = new LinearLayout(this);
+        card.setPadding(dp(18), dp(16), dp(18), dp(16));
+        card.setBackground(roundedRect(card(), dp(8), cardStroke(), dp(1)));
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            card.setElevation(dp(1));
+        }
+
+        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        params.setMargins(0, 0, 0, dp(14));
+        card.setLayoutParams(params);
+        return card;
+    }
+
+    private TextView actionButton(String text, int backgroundColor, int textColor) {
+        TextView button = textView(text, 15, textColor, Typeface.BOLD);
+        button.setGravity(Gravity.CENTER);
+        button.setPadding(dp(14), 0, dp(14), 0);
+        button.setBackground(roundedRect(backgroundColor, dp(8), Color.TRANSPARENT, 0));
+        return button;
+    }
+
+    private TextView textView(String text, int sizeSp, int color, int style) {
+        TextView textView = new TextView(this);
+        textView.setText(text);
+        textView.setTextSize(sizeSp);
+        textView.setTextColor(color);
+        textView.setTypeface(Typeface.DEFAULT, style);
+        return textView;
+    }
+
+    private GradientDrawable roundedRect(int color, int radius, int strokeColor, int strokeWidth) {
+        GradientDrawable drawable = new GradientDrawable();
+        drawable.setShape(GradientDrawable.RECTANGLE);
+        drawable.setColor(color);
+        drawable.setCornerRadius(radius);
+        if (strokeWidth > 0) {
+            drawable.setStroke(strokeWidth, strokeColor);
+        }
+        return drawable;
+    }
+
+    private int dp(int value) {
+        return Math.round(value * getResources().getDisplayMetrics().density);
+    }
+}

app/src/main/java/com/bibli

@@ -0,0 +1,424 @@
+package com.bibliadiaria.app;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.graphics.Color;
+import android.graphics.Typeface;
+import android.graphics.drawable.GradientDrawable;
+import android.os.Build;
+import android.os.Bundle;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.LinearLayout;
+import android.widget.ScrollView;
+import android.widget.TextView;
+
+public class ExtrasActivity extends Activity {
+    // Light mode colors
+    private static final int COLOR_BG_LIGHT = Color.rgb(247, 248, 246);
+    private static final int COLOR_CARD_LIGHT = Color.WHITE;
+    private static final int COLOR_INK_LIGHT = Color.rgb(25, 31, 31);
+    private static final int COLOR_MUTED_LIGHT = Color.rgb(91, 99, 98);
+    private static final int COLOR_STROKE_LIGHT = Color.rgb(219, 226, 222);
+    private static final int COLOR_CARD_STROKE_LIGHT = Color.rgb(229, 232, 230);
+
+    // Dark mode colors
+    private static final int COLOR_BG_DARK = Color.rgb(26, 28, 30);
+    private static final int COLOR_CARD_DARK = Color.rgb(38, 41, 44);
+    private static final int COLOR_INK_DARK = Color.rgb(224, 226, 219);
+    private static final int COLOR_MUTED_DARK = Color.rgb(158, 163, 160);
+    private static final int COLOR_STROKE_DARK = Color.rgb(48, 52, 55);
+    private static final int COLOR_CARD_STROKE_DARK = Color.rgb(58, 62, 65);
+
+    private static final int COLOR_ACCENT = Color.rgb(0, 107, 90);
+    private static final int COLOR_WARM = Color.rgb(217, 75, 61);
+
+    private boolean isEnglish;
+    private boolean isDarkMode;
+
+    private static final String VENI_CREATOR_PRAYER =
+            "Ven, Esp\u00edritu Creador,\n"
+                    + "visita las almas de tus fieles\n"
+                    + "y llena de la gracia divina\n"
+                    + "los corazones que t\u00fa mismo creaste.\n\n"
+                    + "T\u00fa eres nuestro Consolador,\n"
+                    + "don del Dios alt\u00edsimo,\n"
+                    + "fuente viva, fuego, caridad\n"
+                    + "y espiritual unci\u00f3n.\n\n"
+                    + "T\u00fa derramas sobre nosotros\n"
+                    + "los siete dones;\n"
+                    + "t\u00fa eres el dedo de la diestra del Padre,\n"
+                    + "promesa solemne del Padre,\n"
+                    + "que pones en nuestros labios la palabra.\n\n"
+                    + "Enciende tu luz en nuestras mentes,\n"
+                    + "infunde tu amor en nuestros corazones\n"
+                    + "y fortalece con tu fuerza constante\n"
+                    + "la debilidad de nuestro cuerpo.\n\n"
+                    + "Aleja de nosotros al enemigo,\n"
+                    + "danos pronto la paz;\n"
+                    + "siendo t\u00fa nuestro gu\u00eda,\n"
+                    + "evitaremos todo mal.\n\n"
+                    + "Por ti conozcamos al Padre,\n"
+                    + "y tambi\u00e9n al Hijo;\n"
+                    + "y que en ti, Esp\u00edritu de ambos,\n"
+                    + "creamos en todo tiempo.\n\n"
+                    + "Gloria a Dios Padre,\n"
+                    + "y al Hijo que resucit\u00f3,\n"
+                    + "y al Esp\u00edritu Consolador,\n"
+                    + "por los siglos de los siglos.\n\n"
+                    + "Am\u00e9n.";
+
+    private static final String ANGELUS_PRAYER =
+            "El \u00c1ngel del Se\u00f1or anunci\u00f3 a Mar\u00eda.\n"
+                    + "Y concibi\u00f3 por obra y gracia del Esp\u00edritu Santo.\n\n"
+                    + "Dios te salve, Mar\u00eda, llena eres de gracia,\n"
+                    + "el Se\u00f1or es contigo.\n"
+                    + "Bendita t\u00fa eres entre todas las mujeres,\n"
+                    + "y bendito es el fruto de tu vientre, Jes\u00fas.\n"
+                    + "Santa Mar\u00eda, Madre de Dios,\n"
+                    + "ruega por nosotros, pecadores,\n"
+                    + "ahora y en la hora de nuestra muerte.\n"
+                    + "Am\u00e9n.\n\n"
+                    + "He aqu\u00ed la esclava del Se\u00f1or.\n"
+                    + "H\u00e1gase en m\u00ed seg\u00fan tu palabra.\n\n"
+                    + "Dios te salve, Mar\u00eda...\n\n"
+                    + "Y el Verbo se hizo carne.\n"
+                    + "Y habit\u00f3 entre nosotros.\n\n"
+                    + "Dios te salve, Mar\u00eda...\n\n"
+                    + "Ruega por nosotros, Santa Madre de Dios.\n"
+                    + "Para que seamos dignos de alcanzar las promesas de Cristo.\n\n"
+                    + "Infunde, Se\u00f1or, tu gracia en nuestros corazones,\n"
+                    + "para que quienes hemos conocido por el anuncio del \u00c1ngel\n"
+                    + "la encarnaci\u00f3n de tu Hijo Jesucristo,\n"
+                    + "por su pasi\u00f3n y cruz seamos llevados\n"
+                    + "a la gloria de su resurrecci\u00f3n.\n"
+                    + "Por Jesucristo nuestro Se\u00f1or.\n\n"
+                    + "Am\u00e9n.";
+
+    private static final String SALVE_REGINA_PRAYER =
+            "Dios te salve, Reina y Madre de misericordia,\n"
+                    + "vida, dulzura y esperanza nuestra;\n"
+                    + "Dios te salve.\n\n"
+                    + "A ti llamamos los desterrados hijos de Eva;\n"
+                    + "a ti suspiramos, gimiendo y llorando\n"
+                    + "en este valle de l\u00e1grimas.\n\n"
+                    + "Ea, pues, Se\u00f1ora, abogada nuestra,\n"
+                    + "vuelve a nosotros esos tus ojos misericordiosos;\n"
+                    + "y despu\u00e9s de este destierro,\n"
+                    + "mu\u00e9stranos a Jes\u00fas,\n"
+                    + "fruto bendito de tu vientre.\n\n"
+                    + "\u00a1Oh clemente, oh piadosa,\n"
+                    + "oh dulce Virgen Mar\u00eda!\n\n"
+                    + "Ruega por nosotros, Santa Madre de Dios,\n"
+                    + "para que seamos dignos de alcanzar\n"
+                    + "las promesas de nuestro Se\u00f1or Jesucristo.\n\n"
+                    + "Am\u00e9n.";
+
+    private static final String MEMORARE_PRAYER =
+            "Acordaos, oh piados\u00edsima Virgen Mar\u00eda,\n"
+                    + "que jam\u00e1s se ha o\u00eddo decir\n"
+                    + "que ninguno de los que han acudido a vuestra protecci\u00f3n,\n"
+                    + "implorado vuestra asistencia\n"
+                    + "y reclamado vuestro socorro,\n"
+                    + "haya sido abandonado de vos.\n\n"
+                    + "Animado con esta confianza,\n"
+                    + "a vos tambi\u00e9n acudo,\n"
+                    + "oh Madre, Virgen de las v\u00edrgenes;\n"
+                    + "y aunque gimiendo bajo el peso de mis pecados,\n"
+                    + "me atrevo a comparecer ante vuestra presencia soberana.\n\n"
+                    + "No desech\u00e9is, oh Madre de Dios,\n"
+                    + "mis humildes s\u00faplicas;\n"
+                    + "antes bien, escuchadlas y acogedlas benignamente.\n\n"
+                    + "Am\u00e9n.";
+
+    private static final PrayerItem[] PRAYERS = {
+            new PrayerItem("Ven, Esp\u00edritu Creador", "Veni Creator Spiritus", VENI_CREATOR_PRAYER),
+            new PrayerItem("\u00c1ngelus", "Oraci\u00f3n de la Encarnaci\u00f3n", ANGELUS_PRAYER),
+            new PrayerItem("Salve Regina", "Dios te salve, Reina", SALVE_REGINA_PRAYER),
+            new PrayerItem("Acordaos", "Memorare", MEMORARE_PRAYER)
+    };
+
+    private ScrollView scrollView;
+    private LinearLayout listContainer;
+    private LinearLayout detailContainer;
+    private TextView titleText;
+    private PrayerItem selectedPrayer = PRAYERS[0];
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        isEnglish = UpdateManager.isEnglish(this);
+        isDarkMode = UpdateManager.isDarkMode(this);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            getWindow().setStatusBarColor(bg());
+            getWindow().setNavigationBarColor(bg());
+        }
+
+        setContentView(createScreen());
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        boolean currentLanguage = UpdateManager.isEnglish(this);
+        boolean currentDark = UpdateManager.isDarkMode(this);
+        if (currentLanguage != isEnglish || currentDark != isDarkMode) {
+            isEnglish = currentLanguage;
+            isDarkMode = currentDark;
+            recreate();
+        }
+    }
+
+    @Override
+    public void onBackPressed() {
+        if (detailContainer != null && detailContainer.getVisibility() == View.VISIBLE) {
+            showPrayerList();
+            return;
+        }
+        super.onBackPressed();
+    }
+
+    private int bg() { return isDarkMode ? COLOR_BG_DARK : COLOR_BG_LIGHT; }
+    private int card() { return isDarkMode ? COLOR_CARD_DARK : COLOR_CARD_LIGHT; }
+    private int ink() { return isDarkMode ? COLOR_INK_DARK : COLOR_INK_LIGHT; }
+    private int muted() { return isDarkMode ? COLOR_MUTED_DARK : COLOR_MUTED_LIGHT; }
+    private int stroke() { return isDarkMode ? COLOR_STROKE_DARK : COLOR_STROKE_LIGHT; }
+    private int cardStroke() { return isDarkMode ? COLOR_CARD_STROKE_DARK : COLOR_CARD_STROKE_LIGHT; }
+
+    private View createScreen() {
+        FrameLayout root = new FrameLayout(this);
+        root.setBackgroundColor(bg());
+
+        scrollView = new ScrollView(this);
+        scrollView.setFillViewport(true);
+        scrollView.setClipToPadding(false);
+
+        LinearLayout content = new LinearLayout(this);
+        content.setOrientation(LinearLayout.VERTICAL);
+        content.setPadding(dp(20), dp(28), dp(20), dp(28));
+        scrollView.addView(content, new ScrollView.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        content.addView(createTopBar());
+
+        titleText = textView(isEnglish ? "Extras" : "Extras", 34, ink(), Typeface.BOLD);
+        titleText.setIncludeFontPadding(false);
+        LinearLayout.LayoutParams titleParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        titleParams.setMargins(0, dp(18), 0, dp(18));
+        content.addView(titleText, titleParams);
+
+        listContainer = new LinearLayout(this);
+        listContainer.setOrientation(LinearLayout.VERTICAL);
+        for (PrayerItem prayer : PRAYERS) {
+            listContainer.addView(createPrayerCard(prayer));
+        }
+        content.addView(listContainer, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        detailContainer = new LinearLayout(this);
+        detailContainer.setOrientation(LinearLayout.VERTICAL);
+        detailContainer.setVisibility(View.GONE);
+        content.addView(detailContainer, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        root.addView(scrollView, new FrameLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT
+        ));
+
+        root.setOnApplyWindowInsetsListener((view, insets) -> {
+            content.setPadding(
+                    dp(20),
+                    dp(28) + insets.getSystemWindowInsetTop(),
+                    dp(20),
+                    dp(28) + insets.getSystemWindowInsetBottom()
+            );
+            return insets;
+        });
+        root.requestApplyInsets();
+
+        return root;
+    }
+
+    private View createTopBar() {
+        LinearLayout topBar = new LinearLayout(this);
+        topBar.setOrientation(LinearLayout.HORIZONTAL);
+        topBar.setGravity(Gravity.CENTER_VERTICAL);
+
+        TextView label = textView(isEnglish ? "PRAYERS" : "ORACIONES", 12, COLOR_ACCENT, Typeface.BOLD);
+        topBar.addView(label, new LinearLayout.LayoutParams(
+                0,
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                1f
+        ));
+
+        TextView settings = textView(isEnglish ? "Settings" : "Ajustes", 15, COLOR_ACCENT, Typeface.BOLD);
+        settings.setGravity(Gravity.CENTER);
+        settings.setPadding(dp(14), 0, dp(14), 0);
+        settings.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
+        settings.setOnClickListener(view -> startActivity(new Intent(this, SettingsActivity.class)));
+        LinearLayout.LayoutParams settingsParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                dp(40)
+        );
+        settingsParams.setMargins(0, 0, dp(8), 0);
+        topBar.addView(settings, settingsParams);
+
+        TextView home = textView(isEnglish ? "Home" : "Inicio", 15, COLOR_ACCENT, Typeface.BOLD);
+        home.setGravity(Gravity.CENTER);
+        home.setPadding(dp(14), 0, dp(14), 0);
+        home.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
+        home.setOnClickListener(view -> finish());
+        topBar.addView(home, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                dp(40)
+        ));
+
+        return topBar;
+    }
+
+    private View createPrayerCard(PrayerItem prayer) {
+        LinearLayout card = new LinearLayout(this);
+        card.setOrientation(LinearLayout.HORIZONTAL);
+        card.setGravity(Gravity.CENTER_VERTICAL);
+        card.setPadding(dp(18), dp(16), dp(16), dp(16));
+        card.setBackground(roundedRect(card(), dp(8), cardStroke(), dp(1)));
+        card.setOnClickListener(view -> showPrayerDetail(prayer));
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            card.setElevation(dp(1));
+        }
+
+        LinearLayout copy = new LinearLayout(this);
+        copy.setOrientation(LinearLayout.VERTICAL);
+
+        TextView title = textView(prayer.title, 20, ink(), Typeface.BOLD);
+        title.setIncludeFontPadding(false);
+        copy.addView(title);
+
+        TextView subtitle = textView(prayer.subtitle, 14, muted(), Typeface.BOLD);
+        LinearLayout.LayoutParams subtitleParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        subtitleParams.setMargins(0, dp(6), 0, 0);
+        copy.addView(subtitle, subtitleParams);
+
+        card.addView(copy, new LinearLayout.LayoutParams(
+                0,
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                1f
+        ));
+
+        TextView arrow = textView(">", 22, COLOR_ACCENT, Typeface.BOLD);
+        arrow.setGravity(Gravity.CENTER);
+        card.addView(arrow, new LinearLayout.LayoutParams(
+                dp(28),
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        ));
+
+        LinearLayout.LayoutParams cardParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        cardParams.setMargins(0, 0, 0, dp(12));
+        card.setLayoutParams(cardParams);
+        return card;
+    }
+
+    private void renderPrayerDetail() {
+        detailContainer.removeAllViews();
+
+        TextView subtitle = textView(selectedPrayer.subtitle, 14, COLOR_WARM, Typeface.BOLD);
+        detailContainer.addView(subtitle);
+
+        TextView prayer = textView(selectedPrayer.body, 21, ink(), Typeface.NORMAL);
+        prayer.setLineSpacing(dp(5), 1.14f);
+        LinearLayout.LayoutParams prayerParams = new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT
+        );
+        prayerParams.setMargins(0, dp(16), 0, dp(18));
+        detailContainer.addView(prayer, prayerParams);
+
+        TextView backToList = textView(isEnglish ? "Back to extras" : "Volver a extras", 15, COLOR_ACCENT, Typeface.BOLD);
+        backToList.setGravity(Gravity.CENTER);
+        backToList.setPadding(dp(14), 0, dp(14), 0);
+        backToList.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
+        backToList.setOnClickListener(view -> showPrayerList());
+        detailContainer.addView(backToList, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                dp(42)
+        ));
+    }
+
+    private void showPrayerDetail(PrayerItem prayer) {
+        selectedPrayer = prayer;
+        titleText.setText(prayer.title);
+        renderPrayerDetail();
+        listContainer.setVisibility(View.GONE);
+        detailContainer.setVisibility(View.VISIBLE);
+        scrollToTop();
+    }
+
+    private void showPrayerList() {
+        titleText.setText(isEnglish ? "Extras" : "Extras");
+        detailContainer.setVisibility(View.GONE);
+        listContainer.setVisibility(View.VISIBLE);
+        scrollToTop();
+    }
+
+    private void scrollToTop() {
+        if (scrollView != null) {
+            scrollView.post(() -> scrollView.smoothScrollTo(0, 0));
+        }
+    }
+
+    private TextView textView(String text, int sizeSp, int color, int style) {
+        TextView textView = new TextView(this);
+        textView.setText(text);
+        textView.setTextSize(sizeSp);
+        textView.setTextColor(color);
+        textView.setTypeface(Typeface.DEFAULT, style);
+        return textView;
+    }
+
+    private GradientDrawable roundedRect(int color, int radius, int strokeColor, int strokeWidth) {
+        GradientDrawable drawable = new GradientDrawable();
+        drawable.setShape(GradientDrawable.RECTANGLE);
+        drawable.setColor(color);
+        drawable.setCornerRadius(radius);
+        if (strokeWidth > 0) {
+            drawable.setStroke(strokeWidth, strokeColor);
+        }
+        return drawable;
+    }
+
+    private int dp(int value) {
+        return Math.round(value * getResources().getDisplayMetrics().density);
+    }
+
+    private static class PrayerItem {
+        final String title;
+        final String subtitle;
+        final String body;
+
+        PrayerItem(String title, String subtitle, String body) {
+            this.title = title;
+            this.subtitle = subtitle;
+            this.body = body;
+        }
+    }
+}

app/src/main/java/com/bibliadiaria/app/MainActivity.java

@@ -50,10 +50,29 @@ import java.util.concurrent.Executors;
 import org.json.JSONObject;
 
 public class MainActivity extends Activity {
-    private static final int COLOR_BACKGROUND = Color.rgb(247, 248, 246);
+    // Light mode colors
-    private static final int COLOR_CARD = Color.WHITE;
+    private static final int COLOR_BACKGROUND_LIGHT = Color.rgb(247, 248, 246);
-    private static final int COLOR_INK = Color.rgb(25, 31, 31);
+    private static final int COLOR_CARD_LIGHT = Color.WHITE;
-    private static final int COLOR_MUTED = Color.rgb(91, 99, 98);
+    private static final int COLOR_INK_LIGHT = Color.rgb(25, 31, 31);
+    private static final int COLOR_MUTED_LIGHT = Color.rgb(91, 99, 98);
+    private static final int COLOR_STROKE_LIGHT = Color.rgb(229, 232, 230);
+    private static final int COLOR_CHIP_BG_LIGHT = Color.rgb(219, 226, 222);
+    private static final int COLOR_SPEAKER_BG_LIGHT = Color.rgb(229, 244, 240);
+    private static final int COLOR_REFERENCE_BG_LIGHT = Color.rgb(229, 244, 240);
+    private static final int COLOR_TODAY_BG_LIGHT = Color.rgb(255, 239, 236);
+
+    // Dark mode colors
+    private static final int COLOR_BACKGROUND_DARK = Color.rgb(26, 28, 30);
+    private static final int COLOR_CARD_DARK = Color.rgb(38, 41, 44);
+    private static final int COLOR_INK_DARK = Color.rgb(224, 226, 219);
+    private static final int COLOR_MUTED_DARK = Color.rgb(158, 163, 160);
+    private static final int COLOR_STROKE_DARK = Color.rgb(58, 62, 65);
+    private static final int COLOR_CHIP_BG_DARK = Color.rgb(48, 52, 55);
+    private static final int COLOR_SPEAKER_BG_DARK = Color.rgb(45, 65, 60);
+    private static final int COLOR_REFERENCE_BG_DARK = Color.rgb(45, 65, 60);
+    private static final int COLOR_TODAY_BG_DARK = Color.rgb(75, 50, 48);
+
+    // Shared colors (no change between modes)
     private static final int COLOR_ACCENT = Color.rgb(0, 107, 90);
     private static final int COLOR_WARM = Color.rgb(217, 75, 61);
     private static final int COLOR_HOLIDAY_BG = Color.rgb(255, 246, 229);
@@ -120,19 +139,21 @@ public class MainActivity extends Activity {
     private int ttsGeneration;
     private float readingFontSp;
     private boolean isEnglish;
+    private boolean isDarkMode;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
-            getWindow().setStatusBarColor(COLOR_BACKGROUND);
+            getWindow().setStatusBarColor(bg());
-            getWindow().setNavigationBarColor(COLOR_BACKGROUND);
+            getWindow().setNavigationBarColor(bg());
         }
 
         preferences = getSharedPreferences("preferencias_lectura", MODE_PRIVATE);
         readingFontSp = preferences.getFloat("tamano_letra", 20f);
         isEnglish = preferences.getBoolean("is_english", false);
+        isDarkMode = preferences.getBoolean("dark_mode", false);
         selectedDateCalendar = startOfDay(Calendar.getInstance());
         visibleMonthCalendar = startOfMonth(selectedDateCalendar);
         executor = Executors.newSingleThreadExecutor();
@@ -163,15 +184,28 @@ public class MainActivity extends Activity {
     protected void onResume() {
         super.onResume();
         boolean currentLanguage = UpdateManager.isEnglish(this);
-        if (currentLanguage != isEnglish) {
+        boolean currentDark = UpdateManager.isDarkMode(this);
+        if (currentLanguage != isEnglish || currentDark != isDarkMode) {
             isEnglish = currentLanguage;
+            isDarkMode = currentDark;
             recreate();
         }
     }
 
+    // --- Dark mode aware color helpers ---
+    private int bg() { return isDarkMode ? COLOR_BACKGROUND_DARK : COLOR_BACKGROUND_LIGHT; }
+    private int card() { return isDarkMode ? COLOR_CARD_DARK : COLOR_CARD_LIGHT; }
+    private int ink() { return isDarkMode ? COLOR_INK_DARK : COLOR_INK_LIGHT; }
+    private int muted() { return isDarkMode ? COLOR_MUTED_DARK : COLOR_MUTED_LIGHT; }
+    private int stroke() { return isDarkMode ? COLOR_STROKE_DARK : COLOR_STROKE_LIGHT; }
+    private int chipBg() { return isDarkMode ? COLOR_CHIP_BG_DARK : COLOR_CHIP_BG_LIGHT; }
+    private int speakerBg() { return isDarkMode ? COLOR_SPEAKER_BG_DARK : COLOR_SPEAKER_BG_LIGHT; }
+    private int referenceBg() { return isDarkMode ? COLOR_REFERENCE_BG_DARK : COLOR_REFERENCE_BG_LIGHT; }
+    private int todayBg() { return isDarkMode ? COLOR_TODAY_BG_DARK : COLOR_TODAY_BG_LIGHT; }
+
     private View createScreen() {
         FrameLayout root = new FrameLayout(this);
-        root.setBackgroundColor(COLOR_BACKGROUND);
+        root.setBackgroundColor(bg());
 
         ScrollView scrollView = new ScrollView(this);
         scrollView.setFillViewport(true);
@@ -195,7 +229,7 @@ public class MainActivity extends Activity {
                 ViewGroup.LayoutParams.WRAP_CONTENT
         ));
 
-        sourceText = textView(isEnglish ? "Source: Vatican News" : "Fuente: Vatican News", 13, COLOR_MUTED, Typeface.NORMAL);
+        sourceText = textView(isEnglish ? "Source: Vatican News" : "Fuente: Vatican News", 13, muted(), Typeface.NORMAL);
         LinearLayout.LayoutParams sourceParams = new LinearLayout.LayoutParams(
                 ViewGroup.LayoutParams.MATCH_PARENT,
                 ViewGroup.LayoutParams.WRAP_CONTENT
@@ -268,7 +302,7 @@ public class MainActivity extends Activity {
         topRow.addView(createDateChip());
         header.addView(topRow);
 
-        TextView title = textView(isEnglish ? "Word of the day" : "Palabra del día", 34, COLOR_INK, Typeface.BOLD);
+        TextView title = textView(isEnglish ? "Word of the day" : "Palabra del día", 34, ink(), Typeface.BOLD);
         title.setIncludeFontPadding(false);
         LinearLayout.LayoutParams titleParams = new LinearLayout.LayoutParams(
                 ViewGroup.LayoutParams.MATCH_PARENT,
@@ -292,7 +326,7 @@ public class MainActivity extends Activity {
         calendarParams.setMargins(0, dp(2), 0, dp(14));
         header.addView(calendarPanel, calendarParams);
 
-        dateText = textView("", 16, COLOR_MUTED, Typeface.BOLD);
+        dateText = textView("", 16, muted(), Typeface.BOLD);
         header.addView(dateText);
 
         holidayTagsRow = new LinearLayout(this);
@@ -306,7 +340,7 @@ public class MainActivity extends Activity {
         tagsParams.setMargins(0, dp(8), 0, 0);
         header.addView(holidayTagsRow, tagsParams);
 
-        liturgyText = textView("", 16, COLOR_INK, Typeface.NORMAL);
+        liturgyText = textView("", 16, ink(), Typeface.NORMAL);
         liturgyText.setLineSpacing(0, 1.12f);
         LinearLayout.LayoutParams liturgyParams = new LinearLayout.LayoutParams(
                 ViewGroup.LayoutParams.MATCH_PARENT,
@@ -339,7 +373,7 @@ public class MainActivity extends Activity {
         chip.setOrientation(LinearLayout.HORIZONTAL);
         chip.setGravity(Gravity.CENTER_VERTICAL);
         chip.setPadding(dp(12), dp(8), dp(10), dp(8));
-        chip.setBackground(roundedRect(Color.WHITE, dp(8), Color.rgb(219, 226, 222), dp(1)));
+        chip.setBackground(roundedRect(card(), dp(8), chipBg(), dp(1)));
         chip.setContentDescription(isEnglish ? "Choose date" : "Elegir fecha");
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             chip.setElevation(dp(1));
@@ -350,11 +384,11 @@ public class MainActivity extends Activity {
         labelGroup.setOrientation(LinearLayout.VERTICAL);
         labelGroup.setGravity(Gravity.CENTER_VERTICAL);
 
-        dateChipPrimary = textView("", 20, COLOR_INK, Typeface.BOLD);
+        dateChipPrimary = textView("", 20, ink(), Typeface.BOLD);
         dateChipPrimary.setIncludeFontPadding(false);
         labelGroup.addView(dateChipPrimary);
 
-        dateChipSecondary = textView("", 11, COLOR_MUTED, Typeface.BOLD);
+        dateChipSecondary = textView("", 11, muted(), Typeface.BOLD);
         dateChipSecondary.setIncludeFontPadding(false);
         labelGroup.addView(dateChipSecondary);
 
@@ -378,7 +412,7 @@ public class MainActivity extends Activity {
         panel.setOrientation(LinearLayout.VERTICAL);
         panel.setPadding(dp(14), dp(12), dp(14), dp(14));
         panel.setVisibility(View.GONE);
-        panel.setBackground(roundedRect(Color.WHITE, dp(8), Color.rgb(219, 226, 222), dp(1)));
+        panel.setBackground(roundedRect(card(), dp(8), chipBg(), dp(1)));
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             panel.setElevation(dp(4));
         }
@@ -389,7 +423,7 @@ public class MainActivity extends Activity {
 
         monthRow.addView(calendarNavButton("<", view -> changeVisibleMonth(-1)));
 
-        calendarMonthText = textView("", 18, COLOR_INK, Typeface.BOLD);
+        calendarMonthText = textView("", 18, ink(), Typeface.BOLD);
         calendarMonthText.setGravity(Gravity.CENTER);
         monthRow.addView(calendarMonthText, new LinearLayout.LayoutParams(
                 0,
@@ -418,7 +452,7 @@ public class MainActivity extends Activity {
         weekdays.setOrientation(LinearLayout.HORIZONTAL);
         String[] labels = {"L", "M", "X", "J", "V", "S", "D"};
         for (String label : labels) {
-            TextView dayLabel = textView(label, 12, COLOR_MUTED, Typeface.BOLD);
+            TextView dayLabel = textView(label, 12, muted(), Typeface.BOLD);
             dayLabel.setGravity(Gravity.CENTER);
             weekdays.addView(dayLabel, new LinearLayout.LayoutParams(
                     0,
@@ -443,7 +477,7 @@ public class MainActivity extends Activity {
     private TextView calendarNavButton(String text, View.OnClickListener listener) {
         TextView button = textView(text, 22, COLOR_ACCENT, Typeface.BOLD);
         button.setGravity(Gravity.CENTER);
-        button.setBackground(roundedRect(Color.rgb(229, 244, 240), dp(8), Color.TRANSPARENT, 0));
+        button.setBackground(roundedRect(speakerBg(), dp(8), Color.TRANSPARENT, 0));
         button.setOnClickListener(listener);
         button.setContentDescription(text.equals("<") ? (isEnglish ? "Previous month" : "Mes anterior") : (isEnglish ? "Next month" : "Mes siguiente"));
         return button;
@@ -453,7 +487,7 @@ public class MainActivity extends Activity {
         TextView button = textView(text, 13, COLOR_ACCENT, Typeface.BOLD);
         button.setGravity(Gravity.CENTER);
         button.setPadding(dp(8), 0, dp(8), 0);
-        button.setBackground(roundedRect(Color.rgb(229, 244, 240), dp(8), Color.TRANSPARENT, 0));
+        button.setBackground(roundedRect(speakerBg(), dp(8), Color.TRANSPARENT, 0));
         button.setOnClickListener(listener);
 
         LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
@@ -512,7 +546,7 @@ public class MainActivity extends Activity {
         Calendar today = startOfDay(Calendar.getInstance());
 
         for (int cell = 0; cell < 42; cell++) {
-            TextView dayCell = textView("", 16, COLOR_INK, Typeface.BOLD);
+            TextView dayCell = textView("", 16, ink(), Typeface.BOLD);
             dayCell.setGravity(Gravity.CENTER);
             dayCell.setIncludeFontPadding(false);
 
@@ -540,7 +574,7 @@ public class MainActivity extends Activity {
                     dayCell.setBackground(roundedRect(COLOR_HOLIDAY_BG, dp(8), COLOR_HOLIDAY_BORDER, dp(1)));
                 } else if (isSameDay(cellDate, today)) {
                     dayCell.setTextColor(COLOR_WARM);
-                    dayCell.setBackground(roundedRect(Color.rgb(255, 239, 236), dp(8), Color.TRANSPARENT, 0));
+                    dayCell.setBackground(roundedRect(todayBg(), dp(8), Color.TRANSPARENT, 0));
                 } else {
                     dayCell.setBackground(roundedRect(Color.TRANSPARENT, dp(8), Color.TRANSPARENT, 0));
                 }
@@ -983,7 +1017,7 @@ public class MainActivity extends Activity {
         statusBlock = new LinearLayout(this);
         statusBlock.setOrientation(LinearLayout.VERTICAL);
         statusBlock.setPadding(dp(18), dp(16), dp(18), dp(16));
-        statusBlock.setBackground(roundedRect(COLOR_CARD, dp(8), Color.TRANSPARENT, 0));
+        statusBlock.setBackground(roundedRect(card(), dp(8), Color.TRANSPARENT, 0));
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             statusBlock.setElevation(dp(1));
         }
@@ -997,7 +1031,7 @@ public class MainActivity extends Activity {
         progressParams.setMargins(0, 0, dp(12), 0);
         row.addView(progressBar, progressParams);
 
-        statusText = textView(isEnglish ? "Loading today's Word..." : "Cargando la Palabra de hoy...", 16, COLOR_INK, Typeface.NORMAL);
+        statusText = textView(isEnglish ? "Loading today's Word..." : "Cargando la Palabra de hoy...", 16, ink(), Typeface.NORMAL);
         statusText.setLineSpacing(0, 1.16f);
         row.addView(statusText, new LinearLayout.LayoutParams(
                 0,
@@ -1035,7 +1069,7 @@ public class MainActivity extends Activity {
         panel.setOrientation(LinearLayout.VERTICAL);
         panel.setPadding(dp(16), dp(14), dp(16), dp(14));
         panel.setVisibility(View.GONE);
-        panel.setBackground(roundedRect(Color.WHITE, dp(8), Color.rgb(223, 229, 226), dp(1)));
+        panel.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             panel.setElevation(dp(8));
         }
@@ -1043,10 +1077,10 @@ public class MainActivity extends Activity {
         LinearLayout labelRow = new LinearLayout(this);
         labelRow.setGravity(Gravity.CENTER_VERTICAL);
 
-        TextView label = textView(isEnglish ? "Font size" : "Tamaño de letra", 15, COLOR_INK, Typeface.BOLD);
+        TextView label = textView(isEnglish ? "Font size" : "Tamaño de letra", 15, ink(), Typeface.BOLD);
         labelRow.addView(label, new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WRAP_CONTENT, 1f));
 
-        fontValueText = textView(Math.round(readingFontSp) + " sp", 14, COLOR_MUTED, Typeface.BOLD);
+        fontValueText = textView(Math.round(readingFontSp) + " sp", 14, muted(), Typeface.BOLD);
         labelRow.addView(fontValueText);
         panel.addView(labelRow);
 
@@ -1380,7 +1414,7 @@ public class MainActivity extends Activity {
         button.setTextColor(COLOR_ACCENT);
         button.setTextSize(14);
         button.setAllCaps(false);
-        button.setBackground(roundedRect(Color.WHITE, dp(8), Color.rgb(219, 226, 222), dp(1)));
+        button.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
         return button;
     }
 
@@ -1674,7 +1708,7 @@ public class MainActivity extends Activity {
         row.setOrientation(LinearLayout.HORIZONTAL);
         row.setGravity(Gravity.CENTER_VERTICAL);
 
-        TextView titleText = textView(title, titleSizeSp, COLOR_INK, Typeface.BOLD);
+        TextView titleText = textView(title, titleSizeSp, ink(), Typeface.BOLD);
         titleText.setIncludeFontPadding(false);
         row.addView(titleText, new LinearLayout.LayoutParams(
                 0,
@@ -1686,7 +1720,7 @@ public class MainActivity extends Activity {
         speakerButton.setImageResource(R.drawable.ic_speaker_24);
         speakerButton.setColorFilter(COLOR_ACCENT);
         speakerButton.setPadding(dp(8), dp(8), dp(8), dp(8));
-        speakerButton.setBackground(roundedRect(Color.rgb(229, 244, 240), dp(8), Color.TRANSPARENT, 0));
+        speakerButton.setBackground(roundedRect(speakerBg(), dp(8), Color.TRANSPARENT, 0));
         speakerButton.setContentDescription((isEnglish ? "Listen to " : "Escuchar ") + title);
         speakerButton.setOnClickListener(view -> startTtsConversionForText(speechText, controls));
 
@@ -1697,7 +1731,7 @@ public class MainActivity extends Activity {
     }
 
     private TtsControls createTtsControls() {
-        TextView status = textView("", 14, COLOR_MUTED, Typeface.BOLD);
+        TextView status = textView("", 14, muted(), Typeface.BOLD);
         status.setVisibility(View.GONE);
 
         LinearLayout playerPanel = new LinearLayout(this);
@@ -1738,7 +1772,7 @@ public class MainActivity extends Activity {
         seekParams.setMargins(dp(8), 0, dp(8), 0);
         playerPanel.addView(seekBar, seekParams);
 
-        TextView timeText = textView("0:00", 13, COLOR_MUTED, Typeface.BOLD);
+        TextView timeText = textView("0:00", 13, muted(), Typeface.BOLD);
         timeText.setGravity(Gravity.CENTER_VERTICAL);
         playerPanel.addView(timeText, new LinearLayout.LayoutParams(
                 dp(86),
@@ -1797,7 +1831,7 @@ public class MainActivity extends Activity {
         addTtsControlsToCard(card, ttsControls);
 
         if (!section.introduction.isEmpty()) {
-            TextView introText = textView(section.introduction, 16, COLOR_MUTED, Typeface.BOLD);
+            TextView introText = textView(section.introduction, 16, muted(), Typeface.BOLD);
             introText.setLineSpacing(0, 1.14f);
             resizableTextViews.add(introText);
             card.addView(introText);
@@ -1806,7 +1840,7 @@ public class MainActivity extends Activity {
         if (!section.reference.isEmpty()) {
             TextView referenceText = textView(section.reference, 15, COLOR_ACCENT, Typeface.BOLD);
             referenceText.setGravity(Gravity.CENTER_VERTICAL);
-            referenceText.setBackground(roundedRect(Color.rgb(229, 244, 240), dp(8), Color.TRANSPARENT, 0));
+            referenceText.setBackground(roundedRect(referenceBg(), dp(8), Color.TRANSPARENT, 0));
             referenceText.setPadding(dp(10), dp(6), dp(10), dp(6));
             LinearLayout.LayoutParams referenceParams = new LinearLayout.LayoutParams(
                     ViewGroup.LayoutParams.WRAP_CONTENT,
@@ -1816,7 +1850,7 @@ public class MainActivity extends Activity {
             card.addView(referenceText, referenceParams);
         }
 
-        TextView bodyText = textView(section.body, Math.round(readingFontSp), COLOR_INK, Typeface.NORMAL);
+        TextView bodyText = textView(section.body, Math.round(readingFontSp), ink(), Typeface.NORMAL);
         bodyText.setLineSpacing(dp(4), 1.16f);
         resizableTextViews.add(bodyText);
         card.addView(bodyText);
@@ -1841,7 +1875,7 @@ public class MainActivity extends Activity {
         ));
         addTtsControlsToCard(card, ttsControls);
 
-        TextView body = textView(section.body, Math.round(readingFontSp), COLOR_INK, Typeface.NORMAL);
+        TextView body = textView(section.body, Math.round(readingFontSp), ink(), Typeface.NORMAL);
         body.setLineSpacing(dp(4), 1.16f);
         LinearLayout.LayoutParams bodyParams = new LinearLayout.LayoutParams(
                 ViewGroup.LayoutParams.MATCH_PARENT,
@@ -1858,7 +1892,7 @@ public class MainActivity extends Activity {
         LinearLayout card = new LinearLayout(this);
         card.setOrientation(LinearLayout.VERTICAL);
         card.setPadding(padding, padding, padding, padding);
-        card.setBackground(roundedRect(COLOR_CARD, dp(8), Color.rgb(229, 232, 230), dp(1)));
+        card.setBackground(roundedRect(card(), dp(8), stroke(), dp(1)));
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             card.setElevation(dp(1));
         }

app/src/main/java/com/bibliadiaria/app/SettingsActivity.java

@@ -20,10 +20,20 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
 public class SettingsActivity extends Activity {
-    private static final int COLOR_BACKGROUND = Color.rgb(247, 248, 246);
+    // Light mode colors
-    private static final int COLOR_CARD = Color.WHITE;
+    private static final int COLOR_BG_LIGHT = Color.rgb(247, 248, 246);
-    private static final int COLOR_INK = Color.rgb(25, 31, 31);
+    private static final int COLOR_CARD_LIGHT = Color.WHITE;
-    private static final int COLOR_MUTED = Color.rgb(91, 99, 98);
+    private static final int COLOR_INK_LIGHT = Color.rgb(25, 31, 31);
+    private static final int COLOR_MUTED_LIGHT = Color.rgb(91, 99, 98);
+    private static final int COLOR_STROKE_LIGHT = Color.rgb(219, 226, 222);
+
+    // Dark mode colors
+    private static final int COLOR_BG_DARK = Color.rgb(26, 28, 30);
+    private static final int COLOR_CARD_DARK = Color.rgb(38, 41, 44);
+    private static final int COLOR_INK_DARK = Color.rgb(224, 226, 219);
+    private static final int COLOR_MUTED_DARK = Color.rgb(158, 163, 160);
+    private static final int COLOR_STROKE_DARK = Color.rgb(58, 62, 65);
+
     private static final int COLOR_ACCENT = Color.rgb(0, 107, 90);
     private static final int COLOR_WARM = Color.rgb(217, 75, 61);
 
@@ -183,11 +193,11 @@ public class SettingsActivity extends Activity {
                 1f
         ));
 
-        TextView langToggle = actionButton(UpdateManager.isEnglish(this) ? "English" : "Español", COLOR_ACCENT, Color.WHITE);
+        TextView langToggle = actionButton(UpdateManager.isEnglish(this) ? "English" : "Español", COLOR_ACCENT, Color.WHITE);
         langToggle.setOnClickListener(view -> {
             boolean current = UpdateManager.isEnglish(this);
             UpdateManager.setEnglish(this, !current);
-            langToggle.setText(!current ? "English" : "Español");
+            langToggle.setText(!current ? "English" : "Español");
             updateVoiceCard();
         });
         card.addView(langToggle, new LinearLayout.LayoutParams(dp(100), dp(40)));
@@ -338,7 +348,7 @@ public class SettingsActivity extends Activity {
         String voiceId = UpdateManager.getTtsVoice(this, english);
         voiceSubtitleText.setText(english
                 ? "English voices are shown while English is selected"
-                : "Las voces en español se muestran mientras el español esté seleccionado");
+                : "Las voces en español se muestran mientras el español esté seleccionado");
         voiceButton.setText(UpdateManager.getTtsVoiceLabel(english, voiceId));
     }
 
@@ -349,7 +359,7 @@ public class SettingsActivity extends Activity {
                             + UpdateManager.getInstalledVersionName(this)
                             + " (" + UpdateManager.getInstalledVersionCode(this) + ")");
         } catch (Exception error) {
-            installedVersionText.setText(isEnglish ? "Installed version unavailable." : "Versión instalada no disponible.");
+            installedVersionText.setText(isEnglish ? "Installed version unavailable." : "Versión instalada no disponible.");
         }
     }
 

app/src/main/java/com/bibliadiaria/app/UpdateManager.java

@@ -24,6 +24,7 @@ final class UpdateManager {
     static final String PREFS_NAME = "preferencias_lectura";
     static final String KEY_AUTO_UPDATES = "auto_updates_enabled";
     static final String KEY_IS_ENGLISH = "is_english";
+    static final String KEY_DARK_MODE = "dark_mode";
     static final String KEY_TTS_VOICE_ENGLISH = "tts_voice_english";
     static final String KEY_TTS_VOICE_SPANISH = "tts_voice_spanish";
     static final String DEFAULT_TTS_VOICE_ENGLISH = "af_heart";
@@ -89,6 +90,14 @@ final class UpdateManager {
         preferences(context).edit().putBoolean(KEY_IS_ENGLISH, enabled).apply();
     }
 
+    static boolean isDarkMode(Context context) {
+        return preferences(context).getBoolean(KEY_DARK_MODE, false);
+    }
+
+    static void setDarkMode(Context context, boolean enabled) {
+        preferences(context).edit().putBoolean(KEY_DARK_MODE, enabled).apply();
+    }
+
     static VoiceOption[] getTtsVoiceOptions(boolean isEnglish) {
         return isEnglish ? ENGLISH_VOICES : SPANISH_VOICES;
     }
@@ -207,10 +216,10 @@ final class UpdateManager {
 
         boolean english = isEnglish(activity);
         new AlertDialog.Builder(activity)
-                .setTitle(english ? "Update available" : "Actualización disponible")
+                .setTitle(english ? "Update available" : "Actualización disponible")
-                .setMessage((english ? "Version " : "Versión ") + version + (english ? " is ready to download." : " está lista para descargar."))
+                .setMessage((english ? "Version " : "Versión ") + version + (english ? " is ready to download." : " está lista para descargar."))
                 .setPositiveButton(english ? "Download" : "Descargar", (dialog, which) -> openDownload(activity, info.apkUrl))
-                .setNegativeButton(english ? "Later" : "Después", null)
+                .setNegativeButton(english ? "Later" : "Después", null)
                 .show();
     }
 

app/src/main/res/values-night/styles.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="AppTheme" parent="android:style/Theme.Material.NoActionBar">
+        <item name="android:fontFamily">sans</item>
+        <item name="android:windowLightStatusBar">false</item>
+        <item name="android:windowNoTitle">true</item>
+        <item name="android:colorAccent">#006B5A</item>
+        <item name="android:navigationBarColor">#1A1C1E</item>
+        <item name="android:windowActionModeOverlay">true</item>
+    </style>
+</resources>