:root{--bg: #f4eee1;--paper: #fffdf6;--ink: #463a2b;--sub: #8a7a63;--line: #e6dcc6;--accent: #a9814f;--accent-soft: #efe3cd;--green: #7d8f6d;--amber: #c2a15c}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:Hiragino Kaku Gothic ProN,Hiragino Sans,Yu Gothic,system-ui,sans-serif}.app{max-width:1080px;margin:0 auto;padding:16px}.topbar{display:flex;justify-content:space-between;align-items:flex-end;padding:4px 4px 14px;gap:12px;flex-wrap:wrap}h1{margin:0;font-size:26px;letter-spacing:.12em}.tagline{margin:2px 0 0;color:var(--sub);font-size:13px}.topbar-actions{display:flex;align-items:center;gap:12px}.modeSwitch{font-size:12px;color:var(--sub);display:flex;gap:6px;align-items:center;cursor:pointer}.layout{display:grid;grid-template-columns:1fr 320px;gap:14px;align-items:start}.card{background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:14px;box-shadow:0 2px 10px #463a2b0f}.chat{display:flex;flex-direction:column;height:calc(100vh - 150px);min-height:420px}.msgs{flex:1;overflow-y:auto;padding:4px;display:flex;flex-direction:column;gap:10px}.bubble{max-width:85%;padding:10px 13px;border-radius:14px;line-height:1.7;font-size:15px}.bubble p{margin:0}.bubble p+p{margin-top:6px}.bubble.tutor{background:var(--accent-soft);border:1px solid var(--line);border-top-left-radius:4px;align-self:flex-start}.bubble.student{background:var(--paper);border:1px solid var(--accent);border-top-right-radius:4px;align-self:flex-end}.composer{display:flex;gap:8px;padding-top:10px;border-top:1px solid var(--line);flex-wrap:wrap}.composer input{flex:1;min-width:180px;border:1px solid var(--line);border-radius:10px;padding:10px 12px;font-size:15px;background:#fff;color:var(--ink)}.composer input:focus{outline:2px solid var(--accent);border-color:transparent}button{border:none;border-radius:10px;padding:10px 14px;font-size:14px;background:var(--accent);color:#fff;cursor:pointer;font-family:inherit}button:disabled{opacity:.45;cursor:default}button.ghost{background:transparent;color:var(--accent);border:1px solid var(--accent)}.side{display:flex;flex-direction:column;gap:14px}h2{margin:0 0 10px;font-size:15px}.mastery{margin-bottom:12px}.mastery-head{display:flex;justify-content:space-between;align-items:center}.mastery-label{font-size:14px}.badge{font-size:11px;padding:2px 8px;border-radius:999px;background:var(--accent-soft);color:var(--sub)}.badge.solid{background:var(--green);color:#fff}.badge.almost{background:var(--amber);color:#fff}.bar{height:8px;background:var(--line);border-radius:999px;margin-top:5px;overflow:hidden}.fill{height:100%;border-radius:999px;background:var(--accent);transition:width .5s ease}.fill.solid{background:var(--green)}.fill.almost{background:var(--amber)}.gist{margin:4px 0 0;font-size:11px;color:var(--sub)}.empty{color:var(--sub);font-size:13px;margin:0}.mislist{margin:0;padding-left:18px;font-size:13px}.mislist li{margin-bottom:4px}.count{color:var(--sub)}.plist{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}.pbtn{width:100%;display:flex;justify-content:space-between;align-items:center;background:transparent;border:1px solid var(--line);color:var(--ink);padding:9px 11px}.pbtn:hover{border-color:var(--accent)}.pbtn.active{background:var(--accent-soft);border-color:var(--accent)}.pmeta{color:var(--amber);font-size:12px;display:flex;gap:6px;align-items:center}.rec{font-style:normal;color:#fff;background:var(--green);border-radius:999px;padding:1px 7px;font-size:11px}.foot{text-align:center;color:var(--sub);font-size:11px;padding:14px 0 4px}@media (max-width: 880px){.layout{grid-template-columns:1fr}.chat{height:60vh;min-height:340px}}