ㄌㄨˊㄏㄨㄛˇhuǒㄔㄨㄣˊchúnㄑㄧㄥqīng

  1. 爐火古時稱道煉丹爐火」。爐火純青煉丹成功爐火火焰紅色比喻學問技術功夫等到精純完美境地·》:現在爐火純青氣候正是弟兄顯身手時期。」出神入化羽毛未豐

lit. the stove fire has turned bright green (allusion to Daoist alchemy)​ (idiom)​, fig. (of an art, a technique etc)​ brought to the point of perfection
atteindre un haut niveau technique ou une compétence professionnelle