倾城一夜雪苍茫
[qīng chéng yī yè xuĕ cāng máng]
This beautiful expression describes a stunning scene with the entire city blanketed in snow after a night of heavy snowfall ('One-night-of-snow-covering-the-whole-city'). This kind of imagery could refer to pureness covering impurity or the fleeting moments of something beautiful in one’s memory.