Android - button background color shrinks the height of the button
===

I have this button

    <Button
	android:id="@+id/learn"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_marginTop ="5dp"
    android:text="Hello StackOverflow"
    style="@style/home_page_buttons"    
    />   

and I am trying to give it this style

    <style name="home_page_buttons">  
        <item name="android:layout_marginLeft">15dp</item>
        <item name="android:layout_marginRight">15dp</item>
        
        <item name="android:textColor">@color/light_best_blue</item> 
        <item name="android:textStyle">bold</item>   
        <item name="android:color">@color/white</item>  
         <item name="android:background">@color/white</item>
        
    </style>

This line:

     <item name="android:background">@color/white</item>

makes the backgrond white as I wanted, but for some reason, it shrinks down the height of the button and makes it ugly.

Any idea why that happens and how to stop this side effect?

Thanks!    
