煌々と
こうこうと · koukouto · JLPT N1 · noun
brightly
💡 煌 = fire 火 + emperor 皇: the light of a royal fire, doubled by the repeat mark 々 for extra brightness
The repeat mark 々 doubles 煌, so the light grows stronger. Read the kanji as fire plus emperor, and the adverb と turns it into how something shines: brightly.