:root{--paper:#FFF8F2;--white:#fff;--soft:#F3EBE3;--ink:#1A1230;--text:#2C2440;--muted:#5A5270;--light:#8A8298;--pink:#E11D8F;--indigo:#6366F1;--cyan:#0891B2;--amber:#D97706;--mint:#059669;--border:rgba(26,18,48,.10);--shadow:0 14px 34px rgba(26,18,48,.08)}*{box-sizing:border-box}html{scroll-behavior:smooth;overflow-x:hidden}body{margin:0;background:var(--paper);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;line-height:1.78;overflow-x:hidden;padding-top:118px}body.locked{overflow:hidden}a{color:inherit;text-decoration:none}img{display:block;max-width:100%;height:auto}.masthead{position:fixed;z-index:80;top:0;left:0;right:0;height:72px;background:rgba(255,248,242,.97);border-bottom:1px solid var(--border);backdrop-filter:blur(8px)}.masthead-inner{max-width:1160px;height:100%;margin:auto;padding:0 18px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center}.brand{justify-self:center;display:flex;align-items:center;min-height:44px}.brand-logo{max-height:38px;width:auto;object-fit:contain}.brand-text{font-weight:900;font-size:23px;letter-spacing:.1em;color:var(--ink)}.icon-button,.close-button{border:0;background:transparent;color:var(--ink);width:44px;height:44px;cursor:pointer;font-size:24px;border-radius:14px}.icon-button:hover,.icon-button:focus-visible,.close-button:hover,.close-button:focus-visible{background:var(--soft);outline:2px solid transparent}.mast-actions{justify-self:end;display:flex;align-items:center;gap:8px}.app-link,.btn{display:inline-flex;align-items:center;justify-content:center;min-height:44px;border-radius:999px;padding:0 20px;font-weight:800}.app-link{background:linear-gradient(135deg,#6366F1 0%,#E11D8F 55%,#D97706 100%);color:#fff}.chapter-strip{position:fixed;z-index:75;top:72px;left:0;right:0;height:46px;background:#fff;border-bottom:1px solid var(--border);display:flex;justify-content:center;gap:34px;align-items:center}.chapter-strip a{height:46px;display:flex;align-items:center;position:relative;font-size:15px;font-weight:700}.chapter-strip a.active:after{content:"";position:absolute;left:0;right:0;bottom:0;height:3px;background:var(--pink);border-radius:3px}.site-main{min-height:60vh}.wrap{max-width:1160px;margin:0 auto;padding:54px 18px}.hero{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(320px,.95fr);gap:48px;align-items:center;padding-top:48px}.hero-copy{min-width:0}.eyebrow{margin:0 0 8px;color:var(--pink);font-weight:900;letter-spacing:.12em;font-size:13px}.vertical-kicker{writing-mode:vertical-rl;letter-spacing:.3em;font-weight:900;color:var(--indigo);float:left;margin-right:18px;min-height:120px}.hero h1,.page-hero h1{font-size:clamp(28px,4.2vw,34px);line-height:1.25;color:var(--ink);margin:0 0 18px}.hero p,.page-hero p{font-size:16px;margin:0;color:var(--muted)}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}.btn.primary{color:#fff;background:linear-gradient(135deg,#6366F1 0%,#E11D8F 55%,#D97706 100%)}.btn.secondary{background:#fff;border:1px solid var(--border);color:var(--ink)}.btn:hover,.btn:focus-visible{transform:translateY(-1px);box-shadow:var(--shadow);outline:2px solid transparent}.hero-media img,.section-media img,.app-visual img{max-height:360px;margin:auto;object-fit:contain}.hero.no-media{grid-template-columns:1fr}.section{padding:34px 0}.section-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:18px}.section-head h2{margin:0;color:var(--ink);font-size:26px}.section-head p{margin:0;max-width:620px;color:var(--muted)}.tag-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.tag-card,.card,.paper-card,.topic-card,.faq-card{background:#fff;border:1px solid var(--border);border-radius:18px;box-shadow:var(--shadow)}.tag-card{padding:18px}.tag-card h3,.card h3,.paper-card h3,.topic-card h3{margin:0 0 8px;color:var(--ink)}.tag-card p,.card p,.paper-card p,.topic-card p{margin:0;color:var(--muted)}.dot{display:inline-block;width:9px;height:9px;border-radius:50%;margin-right:8px}.dot.pink{background:var(--pink)}.dot.indigo{background:var(--indigo)}.dot.cyan{background:var(--cyan)}.dot.amber{background:var(--amber)}.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(280px,.78fr);gap:34px;align-items:center}.split.no-media{grid-template-columns:1fr}.chapter-list{display:grid;gap:10px;margin-top:18px}.chapter-item{display:grid;grid-template-columns:52px 1fr;gap:14px;padding:14px 0;border-top:1px solid var(--border)}.chapter-item b{font-size:24px;color:var(--pink)}.chapter-item:nth-child(2) b{color:var(--indigo)}.chapter-item:nth-child(3) b{color:var(--cyan)}.chapter-item:nth-child(4) b{color:var(--amber)}.masonry3{columns:3;column-gap:16px}.masonry3 .card{break-inside:avoid;margin:0 0 16px;padding:20px}.masonry3 .card img{max-height:220px;object-fit:contain;margin-bottom:14px}.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.step{background:#fff;border:1px solid var(--border);border-radius:18px;padding:20px}.step b{display:block;font-size:25px;color:var(--indigo);margin-bottom:8px}.topic-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.topic-card{padding:20px}.topic-card:nth-child(2n){transform:translateY(8px)}.shelf-list{display:grid;gap:12px}.shelf-row{display:grid;grid-template-columns:70px 1fr auto;align-items:center;gap:16px;background:#fff;border:1px solid var(--border);border-radius:18px;padding:16px 18px}.shelf-row b{font-size:28px;color:var(--amber)}.shelf-row a{font-weight:800;color:var(--pink)}.rank-list{display:grid;gap:14px}.rank-row{display:grid;grid-template-columns:90px 1fr;gap:18px;background:#fff;border:1px solid var(--border);border-radius:20px;padding:18px}.rank-row .num{font-size:44px;font-weight:900;line-height:1;color:var(--pink)}.rank-row:nth-child(2) .num{color:var(--indigo)}.rank-row:nth-child(3) .num{color:var(--cyan)}.rank-row:nth-child(4) .num{color:var(--amber)}.rank-row:nth-child(5) .num{color:var(--mint)}.timeline{position:relative;padding-left:28px}.timeline:before{content:"";position:absolute;left:7px;top:6px;bottom:6px;width:2px;background:linear-gradient(var(--pink),var(--indigo),var(--cyan),var(--amber))}.time-item{position:relative;background:#fff;border:1px solid var(--border);border-radius:18px;padding:18px 20px;margin:0 0 14px}.time-item:before{content:"";position:absolute;left:-27px;top:24px;width:12px;height:12px;background:var(--pink);border-radius:50%;box-shadow:0 0 0 4px var(--paper)}.status{display:inline-block;padding:4px 10px;border-radius:999px;background:var(--soft);font-size:13px;font-weight:800;color:var(--ink)}.app-block{display:grid;grid-template-columns:minmax(0,.8fr) minmax(0,1.2fr);gap:34px;align-items:center;background:#fff;border:1px solid var(--border);border-radius:22px;padding:24px}.app-icons{display:flex;gap:12px;align-items:center}.app-icons img{max-width:72px;max-height:72px;object-fit:contain}.page-hero{max-width:1160px;margin:0 auto;padding:56px 18px 24px}.page-hero .lead{max-width:760px}.content-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.paper-card{padding:22px}.paper-card.wide{grid-column:1/-1}.paper-card ul{margin:10px 0 0;padding-left:20px}.note{border-left:4px solid var(--pink);padding:16px 18px;background:#fff;border-radius:0 16px 16px 0;color:var(--muted)}.longread{max-width:860px}.longread h2{margin-top:34px;color:var(--ink)}.longread p{color:var(--text)}.faq-list{display:grid;gap:14px}.faq-card{padding:20px}.faq-card h2,.faq-card h3{margin:0 0 8px;color:var(--ink);font-size:19px}.faq-card p{margin:0;color:var(--muted)}.site-footer{background:var(--ink);color:#F7EFE6;margin-top:56px;padding:48px 0 84px}.footer-inner{max-width:1160px;margin:auto;padding:0 18px}.footer-brand{display:flex;align-items:center;gap:14px;margin-bottom:28px}.footer-logo{max-height:36px;max-width:180px;object-fit:contain}.footer-brand strong{display:block;font-size:20px}.footer-brand span{display:block;font-size:12px;opacity:.75;letter-spacing:.12em}.footer-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}.footer-grid h2{font-size:15px;margin:0 0 10px;color:#fff}.footer-grid a{display:block;min-height:32px;opacity:.82}.footer-grid a:hover,.footer-grid a:focus-visible{opacity:1;text-decoration:underline}.footer-note{margin-top:30px;padding-top:22px;border-top:1px solid rgba(255,255,255,.12);opacity:.82}.copyright{opacity:.65;font-size:13px}.overlay{position:fixed;z-index:120;inset:0;background:rgba(26,18,48,.46);opacity:0;transition:.18s;pointer-events:none}.overlay.show{opacity:1;pointer-events:auto}.book-menu,.search-layer{position:fixed;z-index:130;inset:0;display:flex;align-items:center;justify-content:center;padding:20px;visibility:hidden;pointer-events:none;opacity:0;transition:.18s}.book-menu.open,.search-layer.open{visibility:visible;pointer-events:auto;opacity:1}.book-shell{width:min(840px,100%);max-height:88vh;overflow:auto;background:#fff;border-radius:22px;box-shadow:0 26px 80px rgba(26,18,48,.25)}.book-head{position:sticky;top:0;z-index:2;display:flex;align-items:center;justify-content:space-between;padding:16px 18px;background:#fff;border-bottom:1px solid var(--border)}.book-brand{display:flex;align-items:center;gap:12px}.book-brand img{max-height:30px;max-width:150px;object-fit:contain}.book-brand span strong,.book-brand span small{display:block}.book-pages{display:grid;grid-template-columns:1fr 1fr}.book-pages section{padding:22px}.book-pages section:nth-child(odd){background:#fffaf6}.book-pages h2{font-size:17px;color:var(--pink);margin:0 0 10px}.book-pages a{display:block;padding:10px 0;border-bottom:1px solid var(--border)}.book-pages a strong,.book-pages a span{display:block}.book-pages a span{font-size:13px;color:var(--muted);margin-top:2px}.search-card{position:relative;width:min(560px,100%);background:#fff;border-radius:22px;padding:28px;box-shadow:0 26px 80px rgba(26,18,48,.25)}.search-card>.close-button{position:absolute;top:10px;right:10px}.search-card h2{margin:0 0 18px;color:var(--ink)}.search-look{display:flex;align-items:center;gap:12px;min-height:50px;border:1px solid var(--border);border-radius:16px;padding:0 16px;color:var(--muted)}.preset-links{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}.preset-links a{background:var(--soft);border-radius:999px;padding:8px 13px;font-weight:700}.mobile-bottom{display:none}.small-meta{font-size:13px;color:var(--light)}.link-arrow{display:inline-flex;align-items:center;gap:6px;margin-top:10px;font-weight:800;color:var(--pink)}.section-media{min-width:0}.section-media img{border-radius:18px}.callout{background:linear-gradient(135deg,rgba(99,102,241,.1),rgba(225,29,143,.08),rgba(217,119,6,.08));border:1px solid var(--border);border-radius:20px;padding:22px}.contact-box{background:#fff;border:1px solid var(--border);border-radius:20px;padding:22px}.contact-box p{margin:.4em 0}.kbd-link{font-weight:800;color:var(--indigo)}@media(max-width:900px){.tag-grid,.steps{grid-template-columns:repeat(2,1fr)}.topic-grid{grid-template-columns:repeat(2,1fr)}.masonry3{columns:2}.hero,.split,.app-block{grid-template-columns:1fr}.hero-media{order:-1}.hero-media img{max-height:300px}.chapter-strip{gap:18px}.content-grid{grid-template-columns:1fr}.paper-card.wide{grid-column:auto}}@media(max-width:700px){body{padding-top:72px;padding-bottom:64px}.masthead{height:72px}.masthead-inner{grid-template-columns:52px 1fr 92px;padding:0 12px}.desktop-search{display:none}.app-link{padding:0 12px;font-size:14px}.chapter-strip{display:none}.wrap,.page-hero{padding-left:16px;padding-right:16px}.hero{padding-top:28px;gap:24px}.vertical-kicker{display:none}.tag-grid,.steps,.topic-grid{grid-template-columns:1fr}.masonry3{columns:1}.topic-card:nth-child(2n){transform:none}.section{padding:28px 0}.section-head{display:block}.section-head p{margin-top:8px}.shelf-row{grid-template-columns:48px 1fr}.shelf-row a{grid-column:2}.rank-row{grid-template-columns:64px 1fr}.rank-row .num{font-size:34px}.book-menu{align-items:flex-start;padding:12px}.book-shell{max-height:calc(100vh - 24px);border-radius:18px}.book-pages{grid-template-columns:1fr}.book-pages section{padding:18px}.mobile-bottom{position:fixed;z-index:70;left:0;right:0;bottom:0;height:calc(50px + env(safe-area-inset-bottom));padding-bottom:env(safe-area-inset-bottom);display:grid;grid-template-columns:repeat(5,1fr);background:#fff;border-top:1px solid var(--border)}.mobile-bottom a{display:flex;min-width:0;align-items:center;justify-content:center;flex-direction:column;font-size:11px;line-height:1.1;color:var(--muted)}.mobile-bottom a span{font-size:16px;margin-bottom:3px}.mobile-bottom a.active{color:var(--pink);font-weight:900}.site-footer{padding-bottom:86px}.footer-grid{grid-template-columns:repeat(2,1fr)}.search-layer{align-items:flex-start;padding-top:74px}.search-card{width:calc(100vw - 24px);padding:24px}.hero-actions .btn{flex:1}.page-hero{padding-top:36px}.section-media img,.hero-media img{max-height:280px}}@media(max-width:420px){.footer-grid{grid-template-columns:1fr}.masthead-inner{grid-template-columns:48px 1fr 82px}.app-link{padding:0 10px}.brand-logo{max-width:150px}.shelf-row{padding:14px}.hero h1,.page-hero h1{font-size:28px}}