哭着笑沉沦笑着泪倾城
[kū zhe xiào chén lún xiào zhe lèi qīng chéng]
This means 'Laughing in tears and sinking deeper; Smiling through tears as it captivates the city.' It conveys a paradoxical state between joy and sorrow, where the emotions are so intense they mesmerize onlookers. Perhaps used by a person going through complex emotions that can't be easily defined as either happy or sad.