Mobile responsiveness not working when I edit CSS

The issue isn’t the Epik theme itself, since by default the Mobile Responsive features work perfectly from the start. Of course if you change, edit, adjust anything that prevents it from doing what it’s naturally supposed to do (responsive) then you would need to revert back and figure out what all you’re adding/removing that is causing the issue. The issue isn’t the theme itself, it’s something that you’re adding that is most likely throwing everything off. The same thing will happen on any theme that you use.

It’s hard to say what all it could be exactly since there is so much code to examine and look at. Doing this goes beyond the scope of support since this deals with customization and fixing an issue caused by customization. I would recommend reverting back and adding your code in piece by piece to figure out where your issue is coming from.

If you’re developing sites for clients and offering Mobile Responsive features, then now would definitely be a good time to understand how Responsive CSS works so that you can learn to design and make adjustments without breaking any of the Responsive features. I did this a couple years ago by reading tutorials and constantly inspecting and testing code using the browser inspector tools. You can even use something like this to test responsive features in your browser – http://www.studiopress.com/responsive/ You’ll still need to look at a mobile device for somethings, but that link above will still help with some of the basics.

If you’re in a hurry, then the best thing to do is hire someone that already knows how Responsive CSS works, and they should be able to inspect/examine all of your code to pinpoint where all the issues are coming from and get them fixed asap. Shouldn’t take too long as long as they know what they’re doing.