How can subsites be implemented?

Question

CMS

There is such a site san-rasswet.ru, in the section "where to rest" there is something like subsites with their own designs
.
In general, is it possible to make such multi-design sites without rewriting the entire engine?
Do not offer to write on a framework or install several engines.

Answer 1

There are no subsites. Ordinary sections with a unique design no more. Everything can be implemented within a single engine.

Answer 2

The usual if else can be added to the code of a condition for almost any site.
For example, if the category is Asia, we load this design, if the category is Europe, we load this one