I have installed OpenCart 2.0.1 to a domain name http://shop1.abc.com (fake name). Within this installation, I added a new store with domain name http://shop2.abc.com (fake name).
Going to admin page for default shop <http://shop1.abc.com/admin> looks ok. But going to admin page for second shop <http://shop2.abc.com/admin> looks weird as though the CSS stylesheet formatings are gone. Refer to screenshots attached.
Logging on from http://shop2.abc.com/admin will redirect back to http://shop1.abc.com/admin.
Is this normal?
Login page for additional store's admin - shop2-admin.png (40.88 KiB) Viewed 630 times
Login page for default store's admin - shop1-admin.png (38.92 KiB) Viewed 630 times
You can set up as many multistores you want and they are all controlled from the same admin - that is the way the feature works and the beauty of it. You don't have to log in to each store separately, all orders and products are in 1 control panel and you can designate which products appear on which store.
You can look at the stores in my links - I have 30 stores all running from 1 installation/admin of opencart on labeshops.com
Running Opencart v2.2 with multi-stores from http://www.labeshops.com which has links to all my stores.