Separate front-end and back-end interface, or combined?

So far the Laravel applications I've developed tend to be a website front-end, and an administration back-end.

A good example is an ecommerce website. A visitor would have the ability to register and purchase items from within the website.

However, I tend to style the back-end administration area very differently, as its purpose is very different and it doesn't need all of the regular website paraphernalia around it. For this reason, I often create two sub-directories within the "views" directory, called "frontend" and "admin" and I also create separate resource directories for things like CSS and images.

Now I am tasked with creating a more conventional app which doesn't involve a website as such. All users accessing the app would need to login - there would be no "public" areas as such, however there will be administration functions dedicated to only specific admin users.

What I'm wondering is, in the latter example, would you share the same interface, views and styling, rather than creating two completely different interfaces (one for admin, one for regular users)? I realise there is no right or wrong answer, just curious as to what other people do.