I hope you have already checked SyBooks Online
select the UI elements from palette and map them accordingly
For UI Designing in Hybrid Web Container Applications , you need to change the CSS Properties in the developed workflow application.
In general HWC applications are using Jquery framework for the UI . To change the look and feel you can always make the changes in "jquery.mobile.fix.css " and "jquery.mobile-1.0.css " in the project structure .
The Jquery mobile-1.0.css has five Swatches A,B,C,D,E (themes), which can be changed accordingly. Select a theme and change the CSS properties of it .
While deploying the package , select the same theme to which the changes are made. and assign to the user.
Please check this for more information of changing the themes of application
how to change hybrid web container html code
How to show a Splash Screen Hybrid Application
These themes are inherited from Jquery , so you can play with Theme Roller and check how it looks like before applying it to the application
http://themeroller.jquerymobile.com/
http://jqueryui.com/themeroller/