浩如烟海 (hào rú yān hǎi)

vast as the open sea (idiom); fig. extensive (library)

Character breakdown

浩 (hào) · 10 strokes

Phonosemantic compound. 氵 represents the meaning and 告 represents the sound.
如 (rú) · 6 strokes

Depicts a woman (女) obeying spoken (口) orders. Based on the original meaning "obey". The meaning later shifted to "be similar" and "like". 女 also serves as a sound component.
烟 (yān) · 10 strokes

Phonosemantic compound. 火 represents the meaning and 因 represents the sound. Simplified form of 煙.
海 (Hǎi) · 10 strokes

Phonosemantic compound. 氵 represents the meaning and 每 represents the sound.

中国的古籍浩如烟海。
China's ancient classics are as vast as the ocean.
Zhōng guó de gǔ jí hào rú yān hǎi.