Radio/app/src/main/res/layout/dialog_theme_selection.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <TextView
        android:id="@+id/dialog_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/pref_theme_selection_title"
        android:textSize="18sp"
        android:textStyle="bold"
        android:paddingBottom="12dp" />

    <RadioGroup
        android:id="@+id/theme_radio_group"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <RadioButton
            android:id="@+id/radio_theme_follow_system"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/pref_theme_selection_mode_device_default"
            android:textSize="16sp"
            android:padding="8dp"/>

        <RadioButton
            android:id="@+id/radio_theme_light"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/pref_theme_selection_mode_light"
            android:textSize="16sp"
            android:padding="8dp"/>

        <RadioButton
            android:id="@+id/radio_theme_dark"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/pref_theme_selection_mode_dark"
            android:textSize="16sp"
            android:padding="8dp"/>

    </RadioGroup>

</LinearLayout>