I am using Sencha Touch 2.4.1, with the example app generated by "sencha app generate", I got the production css file with size over 800k, it is too big for mobile users even with 3G intenet, even though it can be cached after the first visit.
How can I reduce the css file size?
You could always use a css minifier such as http://cssminifier.com/ I would think that would save you some valuable space :)