Hi @Journalist
OJS 3 frontend is based in BootStrap 3 framework (tks @NateWr) and is possible to develop new themes or customize existing one easily. There´s a theming guide available which may help you (or a frontend developer) to customize a theme as your needings.
https://www.gitbook.com/book/pkp/pkp-theming-guide/details
This a example of customization I’ve coded, spending few days, to my doctorate department:
It is a OJS3 install with a mobile ready built-in theme and a personalized theme color in a CSS file. If you have a frontend developer on your team I think it won’t be hard to him makes required adjustment you need/ask.
But, you ask about OJS and WordPress. I think wordpress is not a complete solution to a journal workflow, of cource you may use e.g. editorial plugins, but OJS is designed to editorial workflow. I know some people use them both, but, as @asmecher said, I don’t know a integration between this webapps but only manual way.
Best
Israel