:root{--bg:#fbfaf7;--paper:#fff;--ink:#263238;--muted:#69757d;--line:#ded9cf;--red:#b84b43;--green:#3f7f6a;--blue:#426b91;--violet:#7660a8;--gold:#a46824;--shadow:0 16px 40px rgba(38,50,56,.08)}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;line-height:1.72}a{color:inherit;text-decoration:none}img{max-width:100%;display:block}.topbar{position:sticky;top:0;z-index:20;display:flex;gap:24px;align-items:center;justify-content:space-between;padding:14px clamp(16px,4vw,44px);background:rgba(251,250,247,.96);border-bottom:1px solid var(--line);backdrop-filter:blur(12px)}.brand{display:flex;align-items:center;gap:10px;font-weight:800;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:34px;height:34px;border-radius:8px;background:var(--ink);color:#fff}.search-wrap{position:relative;width:min(460px,48vw)}#site-search{width:100%;height:40px;border:1px solid var(--line);border-radius:8px;background:#fff;padding:0 14px;font-size:15px}.search-results{position:absolute;right:0;top:46px;width:min(620px,92vw);max-height:70vh;overflow:auto;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);border-radius:8px;padding:8px}.search-results a{display:block;padding:10px 12px;border-radius:6px}.search-results a:hover{background:#f3f0e9}.search-results strong{display:block}.search-results span{font-size:13px;color:var(--muted)}.shell{width:min(1180px,calc(100% - 32px));margin:0 auto;padding:28px 0 64px}.intro-band,.book-hero{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(280px,.6fr);gap:28px;align-items:end;padding:46px 0 28px;border-bottom:1px solid var(--line)}.book-hero{display:block;border-left:8px solid var(--tone);padding-left:24px}.eyebrow{margin:0 0 8px;color:var(--muted);font-weight:700;letter-spacing:0;font-size:14px}.lead{font-size:20px;max-width:760px;color:#48535a}.intro-band h1,.book-hero h1,.lesson-header h1{margin:0;font-size:clamp(32px,5vw,64px);line-height:1.12;letter-spacing:0}.stat-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.stat-grid div{background:#fff;border:1px solid var(--line);border-radius:8px;padding:18px}.stat-grid strong{display:block;font-size:34px;line-height:1}.stat-grid span{color:var(--muted);font-size:14px}.book-nav{display:flex;gap:10px;overflow:auto;padding:18px 0}.book-pill{min-width:158px;border:1px solid var(--line);border-left:6px solid var(--tone);background:#fff;border-radius:8px;padding:10px 12px}.book-pill strong,.book-pill span{display:block}.book-pill span{font-size:12px;color:var(--muted);line-height:1.35}.section-head{display:flex;justify-content:space-between;gap:18px;align-items:end;margin:28px 0 14px}.section-head h2{margin:0;font-size:28px}.section-head p{margin:0;color:var(--muted)}.book-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.book-card,.lesson-card{background:#fff;border:1px solid var(--line);border-radius:8px;overflow:hidden;box-shadow:0 8px 24px rgba(38,50,56,.05)}.book-card a{display:grid;grid-template-columns:122px 1fr;min-height:160px}.book-card img{width:122px;height:100%;object-fit:cover;border-right:5px solid var(--tone)}.book-card div{padding:16px}.book-card span,.lesson-number{color:var(--muted);font-size:13px;font-weight:700}.book-card h3,.lesson-card h3{margin:6px 0 8px;font-size:20px;line-height:1.35}.book-card p,.lesson-card p{margin:0;color:var(--muted);font-size:14px}.diagram-grid{display:grid;grid-template-columns:1fr;gap:16px}.diagram{margin:0;background:#fff;border:1px solid var(--line);border-radius:8px;overflow:hidden}.diagram img{width:100%;height:auto}.diagram figcaption{padding:10px 14px;color:var(--muted);font-size:14px;border-top:1px solid var(--line)}.lesson-grid,.lesson-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.lesson-card a{display:block;height:100%;padding:16px}.lesson-card:hover{border-color:#c7bfae;transform:translateY(-1px);transition:.15s ease}.lesson-shell,.wiki-shell{width:min(1320px,calc(100% - 32px));margin:0 auto;padding:28px 0 72px;display:grid;grid-template-columns:minmax(0,840px) minmax(300px,420px);gap:28px}.lesson-article,.wiki-article{min-width:0}.crumb{display:flex;gap:8px;align-items:center;color:var(--muted);font-size:14px;margin-bottom:18px}.crumb a{text-decoration:underline;text-underline-offset:3px}.lesson-header{padding-bottom:24px;border-bottom:1px solid var(--line)}.source-note{color:var(--muted);margin:14px 0 0}.content-section{background:#fff;border:1px solid var(--line);border-radius:8px;margin:18px 0;padding:26px}.content-section.secondary{background:#fffefb}.content-section h2{font-size:28px;margin:0 0 18px}.content-section h3{font-size:21px;margin:28px 0 10px;color:#314047}.content-section p{margin:0 0 14px;font-size:18px}.content-section ul{margin:0 0 16px;padding-left:1.2em}.content-section li{margin:6px 0}.content-section a{text-decoration:underline;text-decoration-color:#b9ab8d;text-underline-offset:3px}.lesson-aside{position:sticky;top:82px;align-self:start;max-height:calc(100vh - 100px);overflow:auto}.aside-panel{background:#fff;border:1px solid var(--line);border-radius:8px;padding:16px;margin-bottom:16px}.aside-panel h2{font-size:18px;margin:0 0 12px}.scan-gallery{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.scan-gallery figure{margin:0;border:1px solid var(--line);border-radius:8px;overflow:hidden;background:#f6f2ea}.scan-gallery img{width:100%;aspect-ratio:3/4;object-fit:cover;object-position:top}.scan-gallery figcaption{padding:6px 8px;color:var(--muted);font-size:12px}.related-links{display:flex;flex-wrap:wrap;gap:8px}.related-links a{padding:6px 9px;background:#f3f0e9;border-radius:8px;font-size:14px}.pager{display:flex;justify-content:space-between;gap:12px;margin-top:22px}.pager a{flex:1;background:#fff;border:1px solid var(--line);border-radius:8px;padding:12px 14px;color:#33444d}.muted{color:var(--muted)}.code-block,.table-text{white-space:pre-wrap;background:#f6f2ea;border-radius:8px;padding:12px;overflow:auto}
.source-ref{color:var(--muted);font-size:.95em}
.deep-section{border-left:6px solid var(--violet);background:#fff}.deep-note{color:var(--muted);font-size:16px!important}.deep-grid{display:grid;grid-template-columns:1fr;gap:14px}.deep-card{border:1px solid var(--line);border-radius:8px;background:#fbfaf7;padding:18px}.deep-card h3{margin:4px 0 10px!important;font-size:22px!important}.deep-kicker{display:inline-block;color:var(--violet);font-weight:800;font-size:13px}.deep-columns{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:12px}.deep-columns h4{margin:0 0 6px;font-size:15px;color:#43525b}.deep-columns ul{margin-bottom:0}.deep-questions{margin-top:16px;padding:16px;border:1px solid var(--line);border-radius:8px;background:#fffefb}.deep-questions h3{margin-top:0!important}.deep-banner{margin:18px 0;padding:18px 20px;background:#fff;border:1px solid var(--line);border-left:6px solid var(--violet);border-radius:8px}.deep-banner h2{margin:0 0 6px;font-size:22px}.deep-banner p{margin:0;color:var(--muted)}
.top-actions{margin-left:auto}.top-link,.study-entry-action,.study-btn{display:inline-flex;align-items:center;justify-content:center;min-height:40px;border:1px solid var(--line);border-radius:8px;background:#fff;padding:0 14px;font-weight:800;color:#2d3a42}.top-link:hover,.study-entry-action:hover,.study-btn:hover{background:#f3f0e9}.study-entry{display:flex;justify-content:space-between;gap:20px;align-items:center;margin:8px 0 24px;padding:20px;border:1px solid var(--line);border-left:6px solid var(--green);border-radius:8px;background:#fff}.study-entry h2{margin:0;font-size:26px}.study-entry p{margin:4px 0 0;color:var(--muted)}.study-entry-action{background:var(--ink);color:#fff;border-color:var(--ink)}.study-shell{width:min(1240px,calc(100% - 32px));margin:0 auto;padding:30px 0 70px}.study-hero{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(360px,.8fr);gap:22px;align-items:end;padding:42px 0 24px;border-bottom:1px solid var(--line)}.study-hero h1{margin:0;font-size:clamp(34px,5vw,64px);line-height:1.1}.study-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.study-stats div{background:#fff;border:1px solid var(--line);border-radius:8px;padding:14px}.study-stats strong{display:block;font-size:30px;line-height:1}.study-stats span{color:var(--muted);font-size:13px}.study-layout{display:grid;grid-template-columns:310px minmax(0,1fr);gap:18px;margin-top:20px}.companion-panel,.learning-panel{background:#fff;border:1px solid var(--line);border-radius:8px;padding:18px}.companion-panel{position:sticky;top:84px;align-self:start;text-align:center}.companion-avatar{width:168px;height:168px;margin:4px auto 14px;display:grid;place-items:center}.companion-avatar svg{width:100%;height:100%;filter:drop-shadow(0 18px 28px rgba(38,50,56,.18))}.companion-panel h2{margin:0;font-size:26px}.companion-panel p{margin:4px 0 14px;color:var(--muted)}.xp-bar{height:12px;border-radius:99px;background:#eee8dc;overflow:hidden;margin:12px 0 16px}.xp-bar span{display:block;height:100%;width:0;background:linear-gradient(90deg,#3f7f6a,#7660a8);transition:width .2s ease}.study-tabs{display:flex;gap:8px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:12px;margin-bottom:16px}.study-tab{border:1px solid var(--line);background:#fff;border-radius:8px;padding:9px 14px;font-weight:800;cursor:pointer}.study-tab.active{background:var(--ink);border-color:var(--ink);color:#fff}.study-pane{display:none}.study-pane.active{display:block}.quiz-type{display:inline-flex;align-items:center;min-height:30px;border-radius:8px;background:#e8f0ec;color:#2f5f50;padding:0 10px;font-weight:900;font-size:14px}.quiz-card h2{font-size:24px;line-height:1.45;margin:12px 0 12px}.source-workbench{margin:0 0 16px}.source-toggle{margin-bottom:10px}.source-panel{border:1px solid var(--line);border-radius:8px;background:#fffefb;padding:12px}.source-toolbar{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:10px}.source-toolbar span{font-weight:900;margin-right:auto}.tool-btn,.source-thumb{border:1px solid var(--line);border-radius:8px;background:#fff;min-height:34px;padding:0 10px;font-weight:800;color:#33444d;cursor:pointer}.tool-btn.active,.source-thumb.active{background:var(--ink);border-color:var(--ink);color:#fff}.source-thumbs{display:flex;gap:8px;overflow:auto;margin-bottom:10px}.annotation-stage{position:relative;max-height:620px;overflow:auto;border:1px solid var(--line);border-radius:8px;background:#f6f2ea}.annotation-stage img{width:100%;height:auto;display:block}.annotation-stage canvas{position:absolute;left:0;top:0;touch-action:none;cursor:crosshair}.quiz-options{display:grid;grid-template-columns:1fr 1fr;gap:10px}.quiz-option{border:1px solid var(--line);background:#fbfaf7;border-radius:8px;padding:14px;text-align:left;font-size:16px;cursor:pointer}.quiz-option.correct{border-color:#3f7f6a;background:#e7f3ee}.quiz-option.wrong{border-color:#b84b43;background:#f8e9e7}.quiz-result{min-height:48px;margin:14px 0;color:#314047}.quiz-actions{display:flex;gap:10px;flex-wrap:wrap}.study-btn{cursor:pointer}.study-btn.secondary{background:#fbfaf7;color:#33444d}.ask-box label,.feedback-box label{display:block;font-weight:800;margin-bottom:8px}.ask-box textarea,.feedback-box textarea{width:100%;border:1px solid var(--line);border-radius:8px;padding:12px;font:inherit;resize:vertical;background:#fffefb}.answer-box,.feedback-list,.progress-list{margin-top:14px}.answer-hit,.feedback-item,.progress-item{border:1px solid var(--line);border-radius:8px;background:#fbfaf7;padding:12px;margin-bottom:10px}.answer-hit a{text-decoration:underline;text-underline-offset:3px}.progress-controls{display:flex;gap:10px}.progress-controls select{flex:1;border:1px solid var(--line);border-radius:8px;padding:0 10px;font:inherit;background:#fff}.pet-pop{animation:petPop .32s ease}@keyframes petPop{50%{transform:scale(1.06)}}
.learn-head{display:flex;align-items:end;justify-content:space-between;gap:16px;margin-bottom:14px}.learn-head h2{margin:0;font-size:28px}.learn-book-buttons,.chapter-actions{display:flex;gap:8px;flex-wrap:wrap}.learn-book-btn,.chapter-btn{border:1px solid var(--line);border-radius:8px;background:#fff;color:#33444d;font-weight:900;cursor:pointer}.learn-book-btn{min-height:36px;padding:0 11px}.learn-book-btn.active,.chapter-btn.active{background:var(--ink);border-color:var(--ink);color:#fff}.learn-workspace{display:grid;grid-template-columns:250px minmax(0,1fr);gap:16px;align-items:start}.chapter-buttons{display:grid;gap:8px;max-height:680px;overflow:auto;padding-right:4px}.chapter-btn{min-height:48px;padding:8px 10px;text-align:left;line-height:1.35}.chapter-panel{min-width:0}.chapter-panel h2{font-size:30px;margin:0 0 10px;line-height:1.25}.chapter-essence{display:grid;gap:10px;margin:12px 0}.essence-item{border:1px solid var(--line);border-left:5px solid var(--green);border-radius:8px;background:#fbfaf7;padding:12px}.essence-item strong{display:block;margin-bottom:4px}.essence-item p{margin:0;color:#33444d}.learn-source-viewer{margin-top:14px;border:1px solid var(--line);border-radius:8px;background:#fffefb;padding:12px}.lesson-scan-frame{border:1px solid var(--line);border-radius:8px;overflow:auto;max-height:680px;background:#f6f2ea}.lesson-scan-frame img{width:100%;height:auto;display:block}
.lesson-practice{background:#fff;border:1px solid var(--line);border-left:6px solid var(--green);border-radius:8px;margin:18px 0;padding:18px}.lesson-practice-head{display:flex;align-items:end;justify-content:space-between;gap:12px;margin-bottom:12px}.lesson-practice-head h2{margin:0;font-size:26px}.lesson-practice h3{font-size:22px;line-height:1.45;margin:8px 0 12px}.practice-options{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:8px}.practice-option{border:1px solid var(--line);background:#fbfaf7;border-radius:8px;padding:12px;text-align:left;font-size:16px;cursor:pointer}.practice-option.correct{border-color:#3f7f6a;background:#e7f3ee}.practice-option.wrong{border-color:#b84b43;background:#f8e9e7}
.rename-panel{margin-top:12px}.rename-panel input{width:100%;height:40px;border:1px solid var(--line);border-radius:8px;background:#fffefb;padding:0 10px;font:inherit;text-align:center}.rename-actions{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:8px}.rename-actions .study-btn{min-height:36px;padding:0 8px}
@media (max-width:900px){.topbar{align-items:stretch;flex-direction:column;gap:10px}.top-actions{margin-left:0}.top-link{width:100%}.search-wrap{width:100%}.intro-band,.study-hero{grid-template-columns:1fr}.study-stats{grid-template-columns:repeat(2,1fr)}.study-layout{grid-template-columns:1fr}.companion-panel{position:static}.learn-head{display:block}.learn-book-buttons{margin-top:10px}.learn-workspace{grid-template-columns:1fr}.chapter-buttons{grid-template-columns:1fr 1fr;max-height:none}.quiz-options,.practice-options{grid-template-columns:1fr}.lesson-practice-head{display:block}.study-entry{display:block}.study-entry-action{margin-top:12px;width:100%}.book-grid,.lesson-grid,.lesson-list{grid-template-columns:1fr}.book-card a{grid-template-columns:96px 1fr}.lesson-shell,.wiki-shell{grid-template-columns:1fr}.lesson-aside{position:static;max-height:none}.content-section{padding:18px}.content-section p{font-size:16px}.deep-columns{grid-template-columns:1fr}.scan-gallery{grid-template-columns:repeat(2,minmax(0,1fr))}.section-head{display:block}.intro-band h1,.book-hero h1,.lesson-header h1{font-size:34px}}