～ても構(かま)わないIt doesn't matter if, I don't mind

ても構(かま)わない is often used to express that something 'doesn't matter', or that the speaker 'doesn't mind'. This structure is a combination of ても (with verbs and い-Adjectives), or でも (with nouns and な-Adjectives) grouped with the negative conjugation of the う - Verb 構(かま)う, which means 'to brace'. Literally, this expression can be thought of as being similar to 'to not be uptight'. However, it is almost always simply used to convey that there is no issue with something.

ても構(かま)わない may be used with any type of word that appears in its ても or でも conjugation form.

Fun Fact

構(かま)う is usually translated as 'to brace', but the kanji 構(かま) often has the nuance of 'to posture', or 'to pose' (into some type of strong/resistant shape). In the ても構(かま)わない grammar structure, this translates as (A) simply being something that will not cause the speaker to 'posture', 'position', or 'pose' themselves in a resistant way.