Can there be problems when copying the site design?

Question

User interface

Problems, I mean the legal, moral aspect, in the form of angry letters from the donor of the design does not count. Sites vary!

Answer 1

Every design has an author. Another question is what the author allowed with his work to do next.
Free (and paid too) templates usually come with a license, which describes how and under what conditions this template can be used.
Sites with a unique design do not have any such licenses (and therefore, by default, you cannot use it without permission).
Legal problems are possible from the very moment the copyright holder files an application to the court. If he does it of course.
Angry letters in this case will go not as a moral aspect, but as an attempt at a pre-trial settlement (but you can sue without letters).
After that, everything depends on the materials provided by the plaintiff and the judge. The chances that you will have to remove the design and pay compensation are quite real.
PS The theme in this case does not affect anything.

Answer 2

They can, if the donor site did not take this design for free, but ordered it in the studio. Accordingly, he owns the rights to the design of the site. Problems:
1. you may be closed
2. you may be required to pay compensation for using someone else's property.
Point 2 threatens you only in that situation if you start kicking and the owner of the donor site will be principled.
My advice: Go to the Internet and find ready-made free templates.