Android for Beginners : Themes Solution

styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- App branding color for the app bar -->
        <item name="colorPrimary">#009688</item>
        <!-- Darker variant for the status bar and contextual app bars -->
        <item name="colorPrimaryDark">#00796B</item>
        <!-- Theme UI controls like checkboxes and text fields -->
        <item name="colorAccent">#536DFE</item>
    </style>
    
    <!-- Style for header text in the order form -->
    <style name="HeaderTextStyle">
        <item name="android:layout_width">wrap_content</item>
        <item name="android:layout_height">48dp</item>
        <item name="android:gravity">center_vertical</item>
        <item name="android:textAllCaps">true</item>
        <item name="android:textSize">15sp</item>
    </style>
    
</resources>