Android Ribbit Application: using styles

<ImageView
    android:id="@+id/backgroundImage"
    style="@style/AuthBackgroundImage"
    android:contentDescription="@string/content_desc_background" />

<TextView
    android:id="@+id/title"
    style="@style/AuthTitle"/>

<TextView
    android:id="@+id/subtitle"
    android:layout_below="@+id/title"
    style="@style/AuthSubtitle"/>

<LinearLayout
    android:id="@+id/editTextLayout"
    style="AuthFieldContainer"
    android:layout_below="@+id/subtitle"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="60dp">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/usernameField"
        android:hint="@string/username_hint"
        android:textColorHint="@color/light_gray"
        android:textSize="17sp"
        android:maxLength="20"
        android:maxLines="1"
        android:layout_weight="1"/>

    <EditText
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:inputType="textPassword"
        android:id="@+id/passwordField"
        android:hint="@string/password_hint"
        android:textColorHint="@color/light_gray"
        android:textSize="17sp"
        android:maxLines="1"
        android:layout_weight="1"/>

</LinearLayout>

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/login_button_label"
    android:textSize="13sp"
    android:textColor="@color/text_color"
    android:id="@+id/loginButton"
    android:layout_below="@+id/editTextLayout"
    android:layout_alignParentLeft="true"
    android:background="@drawable/button_custom"
    android:layout_marginRight="@dimen/activity_horizontal_margin"
    android:layout_marginLeft="@dimen/activity_horizontal_margin"
    />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/sign_up_text"
    android:id="@+id/signUpText"
    android:textColor="@android:color/white"
    android:layout_below="@+id/loginButton"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="43dp"/>

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="android:editTextBackground">@drawable/apptheme_edit_text_holo_light</item>
</style>

<style name="AuthBackground">
    <item name="android:background">@drawable/background_fill</item>
</style>

<style name="AuthBackgroundImage">
    <item name="android:layout_width">match_parent</item>
    <item name="android:layout_height">match_parent</item>
    <item name="android:layout_alignParentTop">true</item>
    <item name="android:layout_alignParentLeft">true</item>
    <item name="android:src">@drawable/background</item>
    <item name="android:scaleType">fitStart</item>
</style>

<style name="AuthTitle">
    <item name="android:layout_marginTop">32dp</item>
    <item name="android:textColor">@android:color/white</item>
    <item name="android:textSize">60sp</item>
    <item name="android:textStyle">bold</item>
    <item name="android:layout_width">wrap_content</item>
    <item name="android:layout_height">wrap_content</item>
    <item name="android:text">@string/app_name</item>
    <item name="android:layout_alignParentTop">true</item>
    <item name="android:layout_centerHorizontal">true</item>
</style>

<style name="AuthSubtitle" parent="AuthTitle">
    <item name="android:textColor">@android:color/white</item>
    <item name="android:textSize">13sp</item>
    <item name="android:layout_below">@+id/title</item>
    <item name="android:text">@string/subtitle</item>
    <item name="android:layout_alignParentTop">false</item>
    <item name="android:layout_marginTop">0dp</item>
</style>

<style name="AuthFieldContainer">
    <item name="android:layout_centerHorizontal">true</item>
    <item name="android:layout_width">match_parent</item>
    <item name="android:layout_height">wrap_content</item>
    <item name="android:layout_below">@id/subtitle</item>
    <item name="android:layout_marginLeft">@dimen/activity_horizontal_margin</item>
    <item name="android:layout_marginRight">@dimen/activity_horizontal_margin</item>
    <item name="android:layout_marginTop">@dimen/login_vertical_margin</item>
    <item name="android:background">@android:color/white</item>
    <item name="android:orientation">vertical</item>
    <item name="android:paddingTop">@dimen/login_vertical_padding</item>
    <item name="android:paddingBottom">@dimen/login_vertical_padding</item>
    <item name="android:paddingLeft">@dimen/login_horizontal_padding</item>
    <item name="android:paddingRight">@dimen/login_horizontal_padding</item>
</style>