空中楼阁 / 空中樓閣

kōng​zhōng​lóu​gé

unrealistic

something that lacks a solid foundation, such as an unrealistic plan, an unfounded theory, or a castle in the air

这种脱离实际的计划，无异于空中楼阁。

expression

created sense Mar 4, 2026, 02:25 AM