PenciDesign replied
Hi,
Because we want to make the editor has the same width as on the front-end. That's why we've set it to 770px
If you want to change it, let's change the value as you said ( press Ctrl + F5 when edit a post to make sure the cache clear ). And there is no way to change it elsewhere because that file can't be passed the variable. You need to change it for each update.
Best Regards,
PenciDesign