There are several CSS issues present within this plugin, both dependent on the theme running and just running rampantly. I use the Sparkling theme, and have set EBS to use the theme’s files for everything.
Screenshot #1. For some reason, your plugin is causing the text editor to break (see the far right hand end of the editor bar in yellow). The permalink area (underneath the title box) is randomly using your plugin’s tooltip CSS to pull a font-size:14px and make it randomly bigger. This worries me that there are other random bits of code running “rogue” in your plugin.
Screenshot #2. The accordion and the first tabs element are using no custom classes (ie they should be pulling the styling from the theme. The second tabs element is using the ocs-sparkling-tabs custom class which was suggested in Adam Wright’s thread here.