凡事有解。 Every puzzle has an answer.
从轻松入门，到「世界难题」—— 一组流传世界的高难残局。 From gentle warm-ups to the World's Hardest — classic puzzles that stumped the world.
每一种解法都配一张手绘图解，从扫描到大师级技巧，并注明权威出处。 Every technique comes with a hand-drawn diagram — from scanning to master-level, with cited sources.
需要时，一位讲人话的教练：只点破思路、从不直接报答案，把这一步拆成你能自己走通的两三步。可选功能，由你开启。 A coach that talks like a person — it nudges your thinking, never blurts the answer, and breaks the next move into two or three steps you walk yourself. Optional, and entirely up to you.
解不动时，把残局连同你的笔记发给朋友；也能收进残局库，改天再续。 Stuck? Send the position — with your notes — to a friend. Or save it to your library for later.
克制的触感与声响，可随时关掉。核心完全离线，无广告，无追踪；只有你主动开启 AI 教练时才联网。 Restrained haptics and sound, always optional. The core is fully offline — no ads, no tracking; only the optional AI coach ever goes online.
一个九宫格，有 One single grid —
6,670,903,752,021,072,936,960
种填满的方式；
你只需找到，此刻的这一种。
ways to fill it.
You only need to find the one for now.
一个九阶拉丁方 · 6.67 × 10²¹ 种填法 One 9×9 Latin Square · 6.67 × 10²¹ ways to fill
把多余的都拿掉，
只留下解一局的安静。
Strip away the excess.
Leave only the quiet of solving.