:root{color-scheme:dark;--bg: #08090b;--panel: #101114;--panel-2: #15161a;--text: #f2f0ea;--muted: #a7a29a;--muted-2: #6f6b64;--line: rgba(242, 240, 234, .18);--line-strong: rgba(242, 240, 234, .42);--accent: #d8ff3e;--danger: #ff5c39;--radius: 6px;--mono: "IBM Plex Mono", "Roboto Mono", Consolas, monospace;--display: "Didot", "Bodoni 72", "Cormorant Garamond", "Songti SC", serif;--body: "Aptos", "Microsoft YaHei UI", "Noto Sans SC", sans-serif}*{box-sizing:border-box}html{background:var(--bg)}body{margin:0;background:linear-gradient(rgba(242,240,234,.035) 1px,transparent 1px),linear-gradient(90deg,rgba(242,240,234,.025) 1px,transparent 1px),var(--bg);background-size:72px 72px;color:var(--text);font-family:var(--body);letter-spacing:0}button,textarea{font:inherit}a{color:inherit}.app-shell{min-height:100vh;display:grid;grid-template-columns:minmax(220px,286px) minmax(0,1fr);border-top:1px solid var(--line)}.path-rail{min-width:0;min-height:100vh;display:flex;flex-direction:column;justify-content:space-between;gap:28px;padding:28px 18px;background:#08090bf0}.brand-block{border:1px solid var(--line-strong);border-radius:var(--radius);padding:16px}.brand-mark{display:inline-flex;align-items:center;justify-content:center;width:56px;height:56px;border:1px solid var(--accent);color:var(--accent);font-family:var(--mono);font-size:.75rem}.brand-block p,.source-status span,.hero-meta,.section-kicker,.source-type,.reference-index,.reference-action,.save-state{font-family:var(--mono);font-size:.72rem;line-height:1.3;text-transform:uppercase;letter-spacing:0}.brand-block p{margin:18px 0 0;color:var(--muted)}.path-list{display:grid;gap:0;border-top:1px solid var(--line)}.path-item{display:grid;grid-template-columns:38px minmax(0,1fr);gap:12px;padding:15px 0;border-bottom:1px solid var(--line);color:var(--muted-2)}.path-item span{font-family:var(--mono);color:inherit}.path-item p{margin:0;overflow-wrap:anywhere}.path-item.is-current{color:var(--text)}.path-item.is-current span{color:var(--accent)}.source-status{display:grid;grid-template-columns:24px minmax(0,1fr);gap:12px;align-items:start;padding-top:16px;border-top:1px solid var(--line-strong);color:var(--muted)}.source-status svg{width:20px;height:20px;color:var(--accent)}.source-status p{margin:4px 0 0;color:var(--text);font-family:var(--mono);font-size:.75rem;overflow-wrap:anywhere}.lesson-main{min-width:0;border-left:1px solid var(--line)}.lesson-hero{padding:30px 32px 26px;border-bottom:1px solid var(--line-strong);background:#101114b8}.hero-meta{display:flex;flex-wrap:wrap;gap:10px;color:var(--muted)}.hero-meta span{border:1px solid var(--line);border-radius:var(--radius);padding:8px 10px}.hero-title-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:start;margin-top:48px}.display-title{margin:0;color:var(--text);font-family:var(--display);font-size:5.4rem;font-weight:500;line-height:.96;letter-spacing:0;overflow-wrap:anywhere}.hero-controls{display:flex;gap:8px}.icon-button{width:46px;height:46px;display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--line-strong);border-radius:var(--radius);background:transparent;color:var(--text);cursor:pointer}.icon-button svg{width:20px;height:20px}.icon-button:hover:not(:disabled),.icon-button:focus-visible{border-color:var(--accent);color:var(--accent);outline:none}.icon-button:disabled{opacity:.3;cursor:not-allowed}.hero-bottom{display:grid;grid-template-columns:minmax(0,1fr) minmax(180px,260px);gap:24px;align-items:end;margin-top:36px}.hero-bottom p{margin:0;max-width:760px;color:var(--muted);font-size:1rem;line-height:1.8}.progress-block{display:grid;gap:10px;font-family:var(--mono);color:var(--accent)}.progress-track{height:8px;border:1px solid var(--line-strong);border-radius:999px;overflow:hidden;background:var(--bg)}.progress-fill{height:100%;background:var(--accent)}.lesson-grid{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(300px,.88fr);align-items:stretch}.lesson-section{min-width:0;border-bottom:1px solid var(--line);padding:28px 32px}.explanation-panel{border-right:1px solid var(--line)}.section-kicker{margin:0 0 18px;color:var(--accent)}.lesson-section h2{margin:0;font-size:1.8rem;font-weight:600;line-height:1.25;overflow-wrap:anywhere}.explanation-panel p:last-child,.practice-prompt{margin:18px 0 0;color:var(--muted);font-size:1.05rem;line-height:1.85}.reference-section{grid-column:1 / -1}.reference-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border-top:1px solid var(--line-strong);border-left:1px solid var(--line-strong)}.reference-card{min-width:0;min-height:250px;display:flex;flex-direction:column;justify-content:space-between;gap:18px;padding:22px;border-right:1px solid var(--line-strong);border-bottom:1px solid var(--line-strong);background:#101114d6;text-decoration:none}.reference-card:hover,.reference-card:focus-visible{background:var(--panel-2);color:var(--accent);outline:none}.reference-index,.source-type{color:var(--muted)}.reference-card h3{margin:0;color:var(--text);font-size:1.35rem;line-height:1.2;overflow-wrap:anywhere}.reference-card p{margin:0;color:var(--muted);line-height:1.7}.reference-action{display:inline-flex;align-items:center;gap:7px;color:var(--accent)}.reference-action svg{width:15px;height:15px}.vocabulary-panel{border-right:1px solid var(--line)}.term-grid{display:flex;flex-wrap:wrap;gap:8px}.term-chip{display:inline-flex;align-items:center;min-height:34px;padding:7px 10px;border:1px solid var(--line-strong);border-radius:var(--radius);color:var(--text);background:#08090bc2;overflow-wrap:anywhere}.pattern-list{display:grid;gap:12px;margin-top:24px}.pattern-list p{margin:0;padding:14px 0;border-top:1px solid var(--line);color:var(--muted);line-height:1.75}.notebook-heading{display:flex;justify-content:space-between;gap:20px}.notebook-heading svg{width:30px;height:30px;color:var(--accent)}.notebook-panel textarea{width:100%;min-height:178px;margin-top:22px;resize:vertical;border:1px solid var(--line-strong);border-radius:var(--radius);padding:16px;background:#050607;color:var(--text);line-height:1.8}.notebook-panel textarea:focus{border-color:var(--accent);outline:none}.save-state{display:inline-flex;align-items:center;gap:8px;margin-top:12px;color:var(--muted)}.save-state svg{width:15px;height:15px}.save-state.is-ok svg{color:var(--accent)}.save-state.is-error svg{color:var(--danger)}@keyframes editorial-rise{0%{opacity:0;transform:translateY(18px)}to{opacity:1;transform:translateY(0)}}.kinetic{animation:editorial-rise .52s cubic-bezier(.2,.8,.2,1) both}.lesson-grid .kinetic:nth-child(2){animation-delay:80ms}.lesson-grid .kinetic:nth-child(3){animation-delay:.14s}.lesson-grid .kinetic:nth-child(4){animation-delay:.2s}@media(prefers-reduced-motion:reduce){.kinetic{animation:none}}@media(max-width:1180px){.display-title{font-size:4.2rem}.reference-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:860px){.app-shell{grid-template-columns:1fr}.path-rail{min-height:auto}.lesson-main{border-left:0;border-top:1px solid var(--line)}.hero-title-row,.hero-bottom,.lesson-grid{grid-template-columns:1fr}.display-title{font-size:3.1rem}.explanation-panel,.vocabulary-panel{border-right:0}}@media(max-width:620px){.lesson-hero,.lesson-section,.path-rail{padding:22px 18px}.display-title{font-size:2.5rem;line-height:1.04}.reference-grid{grid-template-columns:1fr}.reference-card{min-height:220px}}