泰然自若 [－－－－]

Jyutping taai3 jin4 zi6 joek6
Pinyin tài rán zì ruò

Definitions (CC-CEDICT)
  1. cool and collected (idiom); showing no sign of nerves
  2. perfectly composed
Definitions (Wiktionary)
  1. phrase, idiomatic
    being calm and composed even under the most stubborn and difficult of situations
    (syn.) 若无其事, 若無其事