月光下那一声无奈的叹息阳光下那一抹牵强的笑
[yuè guāng xià nèi yī shēng wú nài de tàn xī yáng guāng xià nèi yī mŏ qiān qiáng de xiào]
It translates as 'a helpless sigh under moonlight and a strained smile in the sunshine', conveying deep emotions of regret or sadness masked with positivity. It shows internal struggles faced when putting up appearances in public versus true feelings in solitude.