Ext JS 4 theming
Ext JS 4 themes leverage Syntactically Awesome StyleSheets (SASS) and Compass (http://compass-style.org/) to enable the use of variables and mixins in stylesheets. Almost all of the styles for Ext JS 4 components can be customized, including colors, fonts, borders, and backgrounds, by simply changing the SASS variables. SASS is an extension of CSS that allows you to keep large stylesheets well-organized; a very good overview and reference can be found at http://sass-lang.com/documentation/file.SASS_REFERENCE.html.
Theming an Ext JS 4 application using Compass and SASS is beyond the scope of this book. Sencha Cmd allows easy integration with these technologies to build SASS projects; however, the SASS language and syntax is a steep learning curve in its own right. Ext JS 4 theming is very powerful and minor changes to the existing themes can quickly change the appearance of your application. You can find out more about Ext JS 4 theming at http://docs.sencha.com/extjs/4.2...
