You can use one base code to create applications for all platforms Cordova supports. For example it is common android UI design to have tabs on top of app,while on iOS tab will be on bottom.Given that you have one www folder within a Cordova Project.

Easier solution is to use merges folder. This folder doesn’t exist by default.Simply create new folder called merges at root of your project

Inside folder you create new directory for each platform i.e. suppose for one Android and other one iOS  you want to customize

Hello World

Hello folks!

#1 Default CSS for all platforms. #2 A specific CSS file for a platform

/* Apply to all */
h1 {
   font-family: sans-serif;
}

p {
   font-family: sans-serif;
   color: black;
}

Here is platform.css:

Listing 3 Default platform CSS file (merges_test/www/css/platform.css)

Listing 4 Android modified CSS (merges_test/merges/android/css/platform.css)

 body {
   background-color: aquamarine;
}

p {
   font-family: sans-serif;
   color: black;
   font-size: 40px;
   font-style: italic;

 

While running application on both iOS and Android you can see difference in below figure