日光倾城不暖心月光侵人照满心
[rì guāng qīng chéng bù nuăn xīn yuè guāng qīn rén zhào măn xīn]
A poetic expression comparing sunshine to warm attention that does not truly reach one's heart, whereas moonlight penetrates deep into the soul, highlighting the distinction between external warmth and inner longing or sadness.