Basic Styling ( Adding the Android CSS )

There are a number of UI conventions that make an Android app look like an Android   app. In the next section, we’ll add the distinctive title bar, lists with rounded corners, finger-friendly links that look like glossy buttons, etc. With the text editor of your choice, create a file named android.
css and add the code shown in then save the file in the same directory as your HTML document.body
 {background-color: #ddd; /* Background color */

color: #222; /* Foreground color used for text */
font-family: Helvetica;
font-size: 14px;
margin: 0; /* Amount of negative space around the
outside of the body */
padding: 0; /* Amount of negative space around the
inside of the body */}
All text on Android is rendered using a custom font named Droid. The Droid font family was specifically built for mobile devices, has excellent character set support, and contains three variants: Droid Sans, Droid
Sans Mono, and Droid Serif. Therefore, specifying a font family of Helvetica as we’ve done here will only have an effect on devices other than Android.
Now let’s attack the header div that contains the main home link (i.e., the logo link) and the primary and secondary site navigation. The first step is to format the logo link as a clickable title bar. Add the following to the android.css file:
#header h1 {
margin: 0;
padding: 0;
}
#header h1 a {
background-color: #ccc;
border-bottom: 1px solid #666;
color: #222;
display: block;
font-size: 20px;
font-weight: bold;
padding: 10px 0;
text-align: center;
text-decoration: none;
}
We’ll format the primary and secondary navigation ul blocks identically, so we can just use the generic tag selectors (i.e., #header ul) as opposed to the tag IDs
 (i.e., #header
ul#utility, #header ul#nav):
#header ul {
list-style: none;
margin: 10px;
padding: 0;
}
#header ul li a {
background-color: #FFFFFF;
border: 1px solid #999999;
color: #222222;

display: block;
font-size: 17px;
font-weight: bold;
margin-bottom: -1px;
padding: 12px 10px;
text-decoration: none;
}
Pretty simple so far, right? With this little bit of CSS, we have already made a big
improvement on the Android page design (Figure 2-5). Next, add some padding to the
content and sidebar divs to indent the text from the edge of the screen a bit (Figure 2-6):
#content, #sidebar {
padding: 10px;
}

You might be wondering why we’re adding padding to the content and sidebar elements instead of setting it globally on the body element itself. The reason is that it’s very common to have elements displayed edge to
edge (as with the header in this example). Because of this, padding applied to the body or some other element that’s wrapped around lots of others can become more trouble than it’s worth.

The content in the footer of this page is basically a rehash of the navigation element (the ul element with the ID nav) at the top of the page, so you can remove the footer from the Android version of the page by setting the display to none, as follows:
#footer {
display: none;
}