Above the waterline, interaction.
At the waterline, language.
Below it, trust.水面上是交互，
水线上是语言，
水面下是可信。

Celestelin looks like a human–AI interaction project: memory, presence, long-term collaboration. Everything a person meets passes through language, and beneath it sits a set of mechanisms that let a long-running agent stay itself and stay trustworthy over time. Each topic here is a problem a running system met first. Pick a field below to see where it runs through the whole structure. Celestelin 看起来是一个人机交互项目：记忆、陪伴、长期协作。人碰到的一切都要经过语言；语言底下，是一整套让长期运行的 agent 保持自己、长期可信的机制。这里的每个议题，都是一个真实运行的系统先撞上的问题。点下面一个领域，看它怎样贯穿整座冰山。