Soft sleeper is much more expensive than hard sleeper, but a lot more comfortable.
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culture
Chinese sleeper trains traditionally have 硬座 (hard seat), 软座 (soft seat), 硬卧 (hard sleeper, open 6-bunk compartment), and 软卧 (soft sleeper, lockable 4-bunk compartment). On newer high-speed lines these have largely been replaced by 一等卧 and 商务座.