for; to; from the standpoint of
Marks the person or entity whose perspective, evaluation, or circumstance is being described. Follows a noun and is often translated as 'for' or 'to'.
For me, family is the most important thing.
This problem may be difficult for beginners.
に対して indicates the target of an action or attitude ('toward'), whereas にとって expresses a perspective or relevance ('for').
Grammaticalized from the particle に and the te-form of the verb 取る (to take), literally 'taking it as...'. The kana spelling is now standard.