na-adjective, noun
Describes something that is up-to-date or in the current style. Often used for fashion, trends, or ways of thinking.
彼女のファッションはいつも当世流だ。
Her fashion is always modern.
当世流の考え方を受け入
It's hard to accept contemporary ways of thinking.
今風 also means 'modern style', but is more casual and often used for fashion or personal taste.
Compound of 当世 (tousei, 'present age') and 流 (ryuu, 'style'). The exact historical derivation is uncertain, but the word has been used since at least the Edo period to refer to contemporary styles.