#author{--teacher-career-size:16px;--teacher-note-size:14px}
@media(max-width:760px){#author{--teacher-career-size:clamp(11px,calc((100vw - var(--gutter) - var(--gutter)) / 24),15px);--teacher-note-size:clamp(11px,3.2vw,13px)}}
:root{--ink:#252525;--gray:#666;--line:#ddd;--paper:#f0f0f0;--yellow:#FFD100;--orange:#FF5800;--blue:#0065BD;--header:90px;--gutter:clamp(24px,5vw,96px)}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:var(--header)}
body{margin:0;color:var(--ink);background:#fff;font:400 16px/1.7 MiSans,'Microsoft YaHei',sans-serif}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;cursor:pointer}
button,a{touch-action:manipulation}
button:focus-visible,a:focus-visible{outline:3px solid var(--ink);outline-offset:5px}
[hidden]{display:none!important}
h1,h2,h3,p{margin:0}
h1,h2,h3{font-weight:600}
img{display:block;max-width:100%;height:auto}
.site-header{height:var(--header);position:sticky;top:0;background:#fffffff5;z-index:30;border-bottom:1px solid var(--line)}
.header-inner{height:100%;padding:0 var(--gutter);max-width:1920px;margin:auto;display:flex;align-items:center;gap:36px}
.wordmark{font-size:27px;font-weight:700;white-space:nowrap;letter-spacing:-.4px}
nav{display:flex;margin-left:auto;gap:clamp(25px,3.6vw,68px)}
nav a{font-weight:500;font-size:14px;padding:12px 0;position:relative;white-space:nowrap}
nav a:after{content:'';height:3px;background:var(--yellow);position:absolute;left:0;right:0;bottom:3px;transform:scaleX(0);transform-origin:left;transition:transform .2s}
nav a:hover:after,nav a[aria-current]:after{transform:scaleX(1)}
.pill{display:inline-flex;align-items:center;justify-content:center;border:0;background:var(--ink);color:#fff;font-size:15px;font-weight:500;padding:14px 30px;min-width:148px;min-height:50px;border-radius:999px;white-space:nowrap}
.pill:hover{background:#444}
.header-cta{margin-left:12px;font-size:13px;min-width:138px;padding:12px 26px;min-height:44px}
.page-section{scroll-margin-top:0;max-width:1920px;margin:auto}
.hero{min-height:calc(100svh - var(--header));padding:0 var(--gutter);display:flex;flex-direction:column}
.hero-main{display:grid;grid-template-columns:1fr 1fr;gap:3.6vw;align-items:center;flex:1;padding:60px 0 58px;min-height:540px}
.intro-label{display:inline-block;font-size:12px;font-weight:500;background:var(--paper);padding:6px 15px;border-radius:30px;margin-bottom:29px}
h1{font-size:clamp(40px,4.2vw,76px);line-height:1.3;letter-spacing:-1.9px;white-space:nowrap}
.highlight{background:var(--yellow);padding:0 .09em;margin:0 .035em;box-decoration-break:clone}
.hero-description{color:var(--gray);font-size:clamp(14px,1.2vw,18px);line-height:1.95;margin-top:28px}
.hero-actions{display:flex;align-items:center;gap:30px;margin-top:35px}
.quiet-link{display:inline-flex;align-items:center;gap:22px;font-size:14px;font-weight:500;min-height:44px}
.quiet-link span{font-size:21px}
.hero-art{padding:22px 0 0;position:relative}
.hero-art:before{content:'';position:absolute;top:0;left:13%;height:6px;width:27%;background:var(--orange)}
.art-frame{aspect-ratio:1.35;display:flex;align-items:center;justify-content:center;overflow:hidden}
.art-frame img{width:100%;object-fit:contain}
.hero-art>p{border-top:6px solid var(--blue);width:76%;margin:12px 0 0 auto;padding-top:15px;display:flex;justify-content:space-between;gap:15px;color:var(--gray);font-size:11px}
.hero-bottom{border-top:1px solid var(--line);padding:25px 0 29px;display:grid;grid-template-columns:1fr 1fr 1fr;align-items:center;gap:25px}
.hero-bottom p{font-size:13px;color:var(--gray);line-height:1.8}
.hero-bottom strong{font-weight:500;color:var(--ink)}
.hero-bottom>a{display:flex;justify-content:center;align-items:center;gap:24px;font-size:12px}
.down-arrow{font-size:26px}
.brand-colors{display:flex;justify-self:end;width:75%;height:19px}
.brand-colors i{width:33.333%}
.brand-colors i:nth-child(1){background:var(--yellow)}
.brand-colors i:nth-child(2){background:var(--orange)}
.brand-colors i:nth-child(3){background:var(--blue)}
.section-heading{display:flex;align-items:flex-end;justify-content:space-between;gap:40px;margin-bottom:30px}
.section-kicker{font-size:13px;font-weight:500;margin-bottom:18px}
h2{font-size:clamp(30px,3vw,50px);line-height:1.4;letter-spacing:-.9px}
.section-note{font-size:13px;line-height:1.9;color:var(--gray);flex-shrink:0}
.mobile-break{display:none}
.mathematics{padding:50px var(--gutter) 50px;background:var(--paper);min-height:calc(100svh - var(--header))}
.network-shell{background:#fff;border-top:5px solid var(--blue)}
.network-stage{padding:13px 22px;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);gap:16px}
.network-stage [role=tablist]{display:flex;gap:23px}
.network-stage button{padding:5px 0;border:0;background:none;font-size:14px;color:var(--gray);border-bottom:3px solid transparent}
.network-stage button[aria-selected=true]{border-bottom-color:var(--yellow);color:var(--ink);font-weight:500}
.network-stage>a{font-size:12px}
.network-stage>a span{margin-left:13px}
iframe{display:block;width:100%;height:min(68svh,690px);min-height:470px;border:0;background:#fff}
.junior-status{min-height:470px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:20px}
.junior-status h3{font-size:28px}
.junior-status p{color:var(--gray);font-size:15px}
.author{padding:65px var(--gutter);display:grid;grid-template-columns:5fr 6fr;gap:clamp(50px,8vw,145px);align-items:center;min-height:calc(100svh - var(--header))}
.author-photo{position:relative;background:var(--paper);border-top:7px solid var(--orange);max-height:680px;overflow:hidden}
.author-photo img{width:100%;height:clamp(470px,42vw,650px);object-fit:cover;object-position:50% 36%}
.photo-caption{position:absolute;bottom:0;left:0;right:0;background:#fffffff5;padding:12px 19px;font-size:11px}
.author-copy .section-kicker{margin-bottom:19px}
.author-lead{font-size:clamp(23px,2vw,34px);line-height:1.6;font-weight:500;margin-top:22px}
.author-intro{font-size:14px;color:var(--gray);line-height:1.95;max-width:510px;margin-top:22px}
.credentials{margin:25px 0 20px;border-top:1px solid var(--line)}
.credentials>div{display:grid;grid-template-columns:92px 1fr;gap:16px;padding:14px 0;border-bottom:1px solid var(--line);font-size:12px}
.credentials dt{font-weight:500}
.credentials dd{margin:0;color:var(--gray);line-height:1.9}
.books{padding:55px var(--gutter) 70px;background:#f8f8f8;min-height:calc(100svh - var(--header))}
.book-stage{display:flex;gap:28px;border-bottom:1px solid var(--line);margin-bottom:30px}
.book-stage button{border:0;border-bottom:5px solid transparent;background:none;font-weight:500;font-size:15px;padding:12px 0}
.book-stage button span{font-size:11px;color:var(--gray);margin-left:12px}
.book-stage button[aria-selected=true]{border-bottom-color:var(--blue)}
.book-stage button:nth-child(2)[aria-selected=true]{border-bottom-color:var(--orange)}
.books-layout{display:grid;grid-template-columns:4fr 7fr;gap:5vw;align-items:start}
.book-series-statement{padding:25px 27px 0;background:#fff;border-top:7px solid var(--blue);position:relative;overflow:hidden}
.book-series-statement.junior{border-top-color:var(--orange)}
.series-tag{display:block;font-size:11px;color:var(--gray);margin-bottom:20px}
.book-series-statement h3{font-size:clamp(23px,2.3vw,38px);line-height:1.5}
.book-series-statement>p{font-size:13px;color:var(--gray);margin:20px 0 10px;line-height:1.9}
.book-series-statement .quiet-link{font-size:12px}
.book-series-statement img{width:100%;margin-top:5px;max-height:235px;object-fit:contain}
.book-list{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:1fr 1fr;column-gap:28px}
.book-list li{padding:17px 0;border-bottom:1px solid var(--line);display:flex;gap:12px;align-items:flex-start;min-height:96px}
.book-list .book-duration{display:inline-flex;min-width:40px;min-height:27px;align-items:center;justify-content:center;background:#e9e9e9;font-size:10px;white-space:nowrap;margin-top:2px}
.book-list h3{font-size:14px;line-height:1.65;font-weight:500}
.book-list p{font-size:11px;line-height:1.8;color:var(--gray);margin-top:4px}
footer{max-width:1920px;margin:auto;padding:30px var(--gutter);display:flex;align-items:center;justify-content:space-between;gap:25px;border-top:1px solid var(--line)}
footer .wordmark{font-size:21px}
footer p,footer>a:last-child{font-size:12px;color:var(--gray)}
@media(min-width:1700px){.hero-main{padding:70px 0}
.hero-art{max-width:810px}
.author{padding-top:85px;padding-bottom:85px}}
@media(max-width:1050px){:root{--header:82px;--gutter:30px}
.header-inner{gap:22px}
.wordmark{font-size:24px}
nav{gap:23px}
nav a{font-size:12px}
.header-cta{min-width:110px;padding:11px 18px;margin-left:0}
.hero-main{gap:20px}
h1{font-size:42px;letter-spacing:-1px}
.hero-description{font-size:14px}
.hero-actions{gap:22px}
.hero-art>p{width:92%;font-size:10px}
.author{gap:45px}
.author-photo img{height:540px}
.author-intro{font-size:13px}
.credentials>div{grid-template-columns:75px 1fr;font-size:11px}
.books-layout{gap:30px;grid-template-columns:4fr 6fr}
.book-list{column-gap:20px}
.book-list h3{font-size:13px}}
@media(max-width:760px){:root{--header:116px;--gutter:22px}
.header-inner{position:relative;display:grid;grid-template-columns:1fr auto;gap:0;height:auto;padding-top:13px}
.site-header{height:var(--header)}
.wordmark{font-size:24px}
.header-cta{font-size:11px;min-width:98px;min-height:37px;padding:7px 17px}
nav{grid-column:1/-1;grid-row:2;display:flex;margin:0;gap:0;justify-content:space-between;padding-top:8px}
nav a{font-size:12px;min-height:43px}
.hero{min-height:calc(100svh - var(--header))}
.hero-main{display:flex;flex-direction:column;align-items:stretch;padding:33px 0 27px;gap:35px;min-height:0}
.intro-label{font-size:10px;margin-bottom:23px;padding:5px 12px}
h1{font-size:clamp(32px,7.9vw,48px);line-height:1.35;letter-spacing:-1.1px}
.hero-description{font-size:13px;line-height:1.95;margin-top:22px}
.hero-actions{margin-top:23px;gap:25px}
.pill{min-width:130px;min-height:46px;font-size:13px;padding:11px 23px}
.header-cta{min-height:37px;min-width:98px;padding:7px 17px;font-size:11px}
.quiet-link{font-size:12px;gap:18px}
.hero-art{padding-top:15px;width:100%;align-self:center;max-width:520px}
.hero-art:before{height:4px}
.art-frame{aspect-ratio:1.7}
.hero-art>p{border-top-width:4px;margin-top:4px;padding-top:10px;font-size:9px;width:82%}
.hero-bottom{padding:18px 0 20px;grid-template-columns:1fr auto;gap:15px}
.hero-bottom p{font-size:11px}
.hero-bottom>a{gap:13px;font-size:10px}
.brand-colors{display:none}
.section-heading{display:block;margin-bottom:24px}
.section-kicker{font-size:11px;margin-bottom:13px}
h2{font-size:29px;letter-spacing:-.8px}
.section-note{font-size:11px;margin-top:15px}
.mobile-break{display:block}
.mathematics{padding-top:34px;padding-bottom:35px}
.network-stage{padding:12px;gap:8px}
.network-stage [role=tablist]{gap:20px}
.network-stage button{font-size:12px}
.network-stage>a{font-size:10px}
.network-stage>a span{margin-left:5px}
iframe{height:640px;min-height:0}
.junior-status{min-height:500px;padding:20px}
.junior-status h3{font-size:24px}
.author{display:flex;flex-direction:column;gap:31px;padding-top:38px;padding-bottom:40px;align-items:stretch}
.author-photo{width:100%;max-height:450px;order:0}
.author-photo img{height:440px;object-position:center 32%}
.author-copy{order:1}
.photo-caption{font-size:10px;padding:10px 14px}
.author-lead{font-size:25px;margin-top:18px}
.author-intro{font-size:13px;margin-top:18px}
.credentials>div{font-size:12px;grid-template-columns:80px 1fr}
.books{padding-top:36px;padding-bottom:36px}
.book-stage{gap:26px;margin-bottom:24px}
.book-stage button{font-size:13px;padding:10px 0}
.book-stage button span{font-size:10px;margin-left:7px}
.books-layout{grid-template-columns:1fr;gap:18px}
.book-series-statement{padding:19px 20px;border-top-width:5px}
.book-series-statement h3{font-size:27px}
.book-series-statement>p{font-size:12px;margin-top:13px}
.book-series-statement img{position:absolute;right:0;bottom:0;width:45%;height:130px;opacity:.22;pointer-events:none}
.book-series-statement>.quiet-link{position:relative;z-index:1}
.series-tag{margin-bottom:10px}
.book-list{column-gap:19px}
.book-list li{gap:9px;min-height:101px;padding:14px 0}
.book-list h3{font-size:12px}
.book-list p{font-size:10px}
.book-list .book-duration{font-size:9px;min-width:32px;min-height:25px}
footer{flex-wrap:wrap;padding-top:24px;padding-bottom:24px;gap:13px}
footer .wordmark{font-size:21px}
footer p{width:100%;order:3;font-size:11px}
footer>a:last-child{font-size:11px}}
@media(max-width:360px){:root{--gutter:17px}
.hero-actions{gap:18px}
.quiet-link{font-size:11px}
.book-list{grid-template-columns:1fr}
.book-list li{min-height:72px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}
*{transition:none!important}}
.mathematics.page-section{max-width:none;padding:0;background:#f0f0f0;min-height:0}
.mathematics iframe{width:100%;height:900px;min-height:0;display:block;border:0;background:#f0f0f0}
@media(max-width:760px){.mathematics.page-section{padding:0}
.mathematics iframe{height:1150px}}
.author-photo{border-top:0}
.author-copy>.section-kicker{display:inline-block;border-top:4px solid #FF5800;padding-top:12px}
.book-series-label{display:flex;align-items:center;gap:16px;border-bottom:1px solid #ddd;padding:10px 0 16px;margin-bottom:30px}
.book-series-label h3{font-size:18px;font-weight:500}
.book-series-label span{font-size:12px;color:#666}
.books-junior{background:#fff}
.books-junior .book-series-statement{background:#f0f0f0}
@media(max-width:760px){.book-series-label{margin-bottom:24px;padding-top:0}
.book-series-label h3{font-size:16px}
#books-title{font-size:27px}}
.junior-books-group{margin-top:64px;scroll-margin-top:110px}
.junior-books-group .book-series-statement{background:#fff}
.junior-books-group .book-series-statement img{max-height:260px}
@media(max-width:760px){.junior-books-group{margin-top:38px;scroll-margin-top:132px}
.junior-books-group .book-series-statement img{position:static;width:100%;height:210px;opacity:1;max-height:none;margin-top:12px;object-fit:contain}}
.author-marketing{grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:clamp(38px,5vw,88px);padding-top:64px;padding-bottom:64px;align-items:start}
.author-marketing .author-photo{max-height:none;position:sticky;top:calc(var(--header) + 32px)}
.author-marketing .author-photo img{height:clamp(610px,53vw,820px);object-position:50% 36%}
.author-marketing .author-copy{min-width:0}
.author-marketing .section-kicker{margin-bottom:16px}
.author-marketing h2{font-size:clamp(32px,3vw,46px);line-height:1.25;letter-spacing:-1px}
.author-degree{font-size:clamp(22px,2.1vw,30px);font-weight:600;line-height:1.45;margin-top:15px}
.author-founder{font-size:clamp(14px,1.25vw,18px);font-weight:500;margin-top:5px;line-height:1.6}
.author-results{display:grid;grid-template-columns:.9fr 1.25fr 1fr;gap:20px;margin:28px 0 0;padding:24px 0;border-top:1px solid #bdbdbd;border-bottom:1px solid #bdbdbd}
.author-results>div{display:flex;flex-direction:column;min-width:0;gap:9px}
.author-results dt{order:2;font-size:12px;line-height:1.6;color:#666}
.author-results dd{order:1;margin:0;font-weight:600;font-size:clamp(40px,4.5vw,74px);line-height:1.08;letter-spacing:-2px;white-space:nowrap;font-variant-numeric:lining-nums tabular-nums}
.author-results small{font-size:18px;font-weight:500;margin-left:5px;letter-spacing:0}
.author-results .result-plus{font-size:.57em;vertical-align:top;position:relative;top:.08em;letter-spacing:0;margin-left:2px}
.author-proof{display:flex;flex-wrap:wrap;gap:15px 28px;list-style:none;padding:0;margin:21px 0 24px}
.author-proof li{display:flex;align-items:baseline;gap:7px;font-size:12px;line-height:1.6}
.author-proof strong{font-weight:600;font-size:15px}
.author-proof span{color:#666}
.author-marketing .author-lead{font-size:18px;font-weight:500;line-height:1.7;margin-top:0}
.author-marketing .author-intro{max-width:none;font-size:13px;line-height:1.85;margin-top:10px}
.author-marketing .credentials{margin:19px 0 8px}
.author-marketing .credentials>div{grid-template-columns:64px 1fr;gap:17px;font-size:12px;padding:14px 0}
.author-career{list-style:none;padding:0;margin:0;display:grid;gap:7px}
.author-career strong{font-weight:500;color:#252525}
.author-marketing .quiet-link{font-size:13px}
@media(min-width:1700px){.author-marketing{padding-top:80px;padding-bottom:80px}
.author-marketing .author-intro,.author-marketing .credentials>div,.author-results dt{font-size:14px}
.author-marketing .author-lead{font-size:21px}}
@media(max-width:1050px) and (min-width:761px){.author-marketing{grid-template-columns:minmax(0,4fr) minmax(0,6fr);gap:30px}
.author-results{gap:10px}
.author-results dd{font-size:44px}
.author-results dt{font-size:11px}
.author-proof{gap:10px 18px}
.author-proof strong{font-size:13px}
.author-marketing .author-lead{font-size:17px}
.author-marketing .author-photo img{height:650px}}
@media(max-width:760px){.author-marketing{display:flex;gap:28px;padding-top:38px;padding-bottom:40px}
.author-marketing .author-photo{position:relative;top:auto;max-height:none}
.author-marketing .author-photo img{height:420px;object-position:center 32%}
.author-marketing h2{font-size:34px}
.author-degree{font-size:24px;margin-top:13px}
.author-founder{font-size:14px}
.author-results{gap:12px;padding:21px 0;margin-top:24px}
.author-results dd{font-size:clamp(36px,9.8vw,66px);letter-spacing:-1.5px}
.author-results dt{font-size:11px}
.author-results small{font-size:14px;margin-left:3px}
.author-proof{gap:12px 20px;margin:18px 0 22px}
.author-proof li{font-size:11px}
.author-proof strong{font-size:14px}
.author-marketing .author-lead{font-size:18px}
.author-marketing .credentials>div{grid-template-columns:56px 1fr;gap:12px;font-size:12px}}
@media(max-width:360px){.author-results{gap:9px}
.author-results dd{font-size:34px}
.author-results dt{font-size:10px}
.author-proof{gap:10px 15px}
.author-marketing .author-photo img{height:370px}}
.books-editorial{padding-top:72px;padding-bottom:76px;background:#f8f8f8;min-height:0}
.books-editorial .books-heading{margin-bottom:48px;max-width:100%}
.books-editorial .books-heading>p{font-size:16px;color:#666;line-height:1.8;margin-bottom:14px}
.books-editorial #books-title{font-size:clamp(32px,3.25vw,52px);line-height:1.35;letter-spacing:-1px;text-wrap:balance}
.books-editorial .book-collection{--collection-accent:#0065BD}
.books-editorial .collection-junior{--collection-accent:#FF5800}
.books-editorial .collection-summary{border-top:5px solid var(--collection-accent);display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);column-gap:clamp(32px,6vw,100px);padding:28px 0 30px;border-bottom:1px solid #ddd}
.books-editorial .collection-title h3{font-size:30px;line-height:1.4;font-weight:600;letter-spacing:-.6px}
.books-editorial .collection-title>span{font-size:14px;color:#666;white-space:nowrap}
.books-editorial .collection-counts{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:20px 0 0;max-width:470px}
.books-editorial .collection-counts>div{display:flex;align-items:baseline;gap:8px;flex-wrap:wrap}
.books-editorial .collection-counts dt{font-size:13px;color:#666;order:2}
.books-editorial .collection-counts dd{font-size:36px;font-weight:600;line-height:1.3;letter-spacing:-1px;margin:0;order:1;font-variant-numeric:lining-nums tabular-nums}
.books-editorial .collection-method{min-width:0;align-self:center}
.books-editorial .collection-method h4{font-size:16px;font-weight:500;line-height:1.7;margin:0 0 14px}
.books-editorial .question-tiers{display:grid;gap:28px;list-style:none;padding:0;margin:0;max-width:440px}
.books-editorial .tiers-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.books-editorial .tiers-2{grid-template-columns:repeat(2,minmax(0,1fr));max-width:310px}
.books-editorial .question-tiers li{position:relative;border-top:2px solid var(--collection-accent);padding:9px 0 0;font-size:22px;font-weight:500;line-height:1.5}
.books-editorial .question-tiers li+li:before{content:'+';position:absolute;left:-20px;top:9px;color:#999;font-size:18px;font-weight:400}
.books-editorial .collection-method>p{font-size:13px;color:#666;line-height:1.8;margin-top:12px}
.books-editorial .book-list{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:24px;list-style:none;padding:22px 0 0;margin:0}
.books-editorial .book-list li{display:flex;flex-direction:column;align-items:stretch;gap:0;min-width:0;min-height:0;padding:0 0 22px;border-bottom:1px solid #ddd}
.books-editorial .book-list .book-duration{display:none}
.books-editorial .book-list .book-cover{order:-1;display:flex;align-items:center;justify-content:center;width:100%;height:clamp(190px,17vw,260px);margin:0 0 12px;padding:5px 0}
.books-editorial .book-cover img{display:block;width:100%;height:100%;max-width:280px;object-fit:contain;transition:transform .18s ease}
.books-editorial .book-cover:focus-visible{outline:3px solid #252525;outline-offset:3px}
.books-editorial .book-list .book-copy{padding:0;min-width:0}
.books-editorial .book-list h3{font-size:16px;line-height:1.65;font-weight:500;letter-spacing:0;overflow-wrap:anywhere}
.books-editorial .book-list p{font-size:13px;line-height:1.8;color:#666;margin-top:5px;overflow-wrap:anywhere}
.books-editorial .collection-explore{font-size:14px;margin-top:16px;min-height:44px}
.books-editorial .junior-books-group{margin-top:64px;scroll-margin-top:calc(var(--header) + 24px)}
.books-editorial .collection-junior .book-list{grid-template-columns:repeat(6,minmax(0,1fr));gap:20px}
@media(hover:hover) and (prefers-reduced-motion:no-preference){.books-editorial .book-cover:hover img{transform:translateY(-4px)}}
@media(min-width:1700px){.books-editorial .book-list h3{font-size:18px}
.books-editorial .collection-counts dd{font-size:40px}}
@media(max-width:1279px){.books-editorial .book-list{grid-template-columns:repeat(4,minmax(0,1fr));gap:22px}
.books-editorial .collection-junior .book-list{grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}
.books-editorial .book-list .book-cover{height:220px}
.books-editorial .collection-counts>div{gap:4px}
.books-editorial .collection-counts dd{font-size:32px}}
@media(max-width:1000px) and (min-width:761px){.books-editorial .book-list{grid-template-columns:repeat(3,minmax(0,1fr))}
.books-editorial .collection-summary{column-gap:32px}
.books-editorial .collection-counts{gap:12px}
.books-editorial .collection-counts>div{flex-direction:column;gap:2px}
.books-editorial .collection-title h3{font-size:28px}
.books-editorial .question-tiers{gap:22px}
.books-editorial .question-tiers li+li:before{left:-17px}}
@media(max-width:760px){.books-editorial{padding-top:40px;padding-bottom:40px}
.books-editorial .books-heading>p{font-size:13px;margin-bottom:11px;max-width:28em}
.books-editorial #books-title{font-size:30px;line-height:1.4;letter-spacing:-.7px}
.books-editorial .collection-summary{grid-template-columns:minmax(0,1fr);gap:24px;padding:20px 0 24px;border-top-width:4px}
.books-editorial .collection-counts{gap:14px;margin-top:16px;max-width:420px}
.books-editorial .collection-counts>div{gap:5px;flex-direction:column}
.books-editorial .collection-counts dd{font-size:32px;letter-spacing:-.6px}
.books-editorial .collection-method h4{font-size:14px;margin-bottom:11px}
.books-editorial .question-tiers{max-width:380px;gap:25px}
.books-editorial .tiers-2{max-width:260px}
.books-editorial .question-tiers li{font-size:20px;padding-top:7px}
.books-editorial .question-tiers li+li:before{left:-18px;top:7px;font-size:17px}
.books-editorial .collection-method>p{font-size:13px;margin-top:10px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:22px 18px;padding-top:18px}
.books-editorial .book-list li{padding:0 0 18px;min-height:0}
.books-editorial .book-list .book-cover{height:clamp(154px,43vw,235px);margin-bottom:10px;padding:0}
.books-editorial .book-list p{font-size:12px;margin-top:5px}
.books-editorial .collection-explore{font-size:13px;margin-top:12px}
.books-editorial .junior-books-group{margin-top:40px}}
@media(max-width:359px){.books-editorial .collection-counts{gap:10px}
.books-editorial .collection-counts dd{font-size:30px}
.books-editorial .book-list .book-cover{height:150px}}
@media(prefers-reduced-motion:reduce){.books-editorial .book-cover img{transition:none}}
.hero .hero-main{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:clamp(24px,4vw,72px);padding-top:48px;padding-bottom:48px}
.hero .intro-label{background:none;padding:0;border-radius:0;font-size:14px;color:#666;margin-bottom:25px}
.hero h1{font-size:clamp(44px,4.6vw,68px);line-height:1.3;letter-spacing:-1.6px;white-space:normal}
.hero .hero-description{font-size:17px;line-height:1.9;max-width:32em;margin-top:26px;text-wrap:pretty}
.hero .hero-actions{margin-top:30px;gap:28px}
.hero .hero-contact{border:0;background:none;padding:0;font-size:15px;min-height:48px}
.hero .hero-art{padding-top:22px;max-width:580px;width:100%;justify-self:end}
.hero .art-frame{aspect-ratio:540/470}
.hero .hero-art>p{font-size:12px;width:88%;padding-top:13px}
.hero .hero-bottom{grid-template-columns:1fr auto;padding:20px 0 25px}
.hero .hero-bottom>a{justify-content:flex-end}
@media(max-width:1050px) and (min-width:761px){.hero h1{font-size:44px}
.hero .hero-description{font-size:15px}}
@media(max-width:760px){.site-header .header-inner{padding-top:10px}
.site-header nav{padding-top:4px}
.site-header nav a{min-height:39px}
.hero .hero-main{display:flex;gap:30px;padding-top:30px;padding-bottom:25px;min-height:0}
.hero .intro-label{font-size:13px;margin-bottom:18px}
.hero h1{font-size:clamp(32px,9vw,42px);line-height:1.35;letter-spacing:-1px}
.hero .hero-description{font-size:15px;margin-top:20px;line-height:1.85}
.hero .hero-actions{margin-top:23px;gap:24px}
.hero .hero-contact{font-size:14px}
.hero .hero-art{max-width:420px;padding-top:14px;align-self:center}
.hero .art-frame{aspect-ratio:1.55}
.hero .hero-art>p{font-size:10px;padding-top:10px}
.hero .hero-bottom{padding:17px 0 20px;gap:14px}}
@media(max-width:359px){.hero .hero-description{font-size:14px}
.hero .hero-actions{gap:20px}
.hero .hero-art>p{gap:10px}}
#books-tsinghua{margin-top:76px;padding-top:34px;border-top:5px solid #0065BD;scroll-margin-top:calc(var(--header) + 24px)}
#books-tsinghua .exam-series-heading{margin-bottom:30px}
#books-tsinghua .exam-series-heading>p{font-size:16px;line-height:1.8;color:#666;margin:0 0 12px}
#books-tsinghua .exam-series-heading h2{font-size:clamp(30px,2.8vw,44px);line-height:1.4;letter-spacing:-.8px;font-weight:600;margin:0;text-wrap:balance}
#books-tsinghua .exam-books{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:40px}
#books-tsinghua .exam-book{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:center;gap:24px;min-width:0;padding:18px 0 30px;border-bottom:1px solid #ddd}
#books-tsinghua .exam-book-cover{display:flex;align-items:center;justify-content:center;min-width:0;width:100%;height:clamp(240px,24vw,350px)}
#books-tsinghua .exam-book-cover img{display:block;object-fit:contain;width:100%;height:100%;max-width:350px}
#books-tsinghua .exam-book-copy{min-width:0}
#books-tsinghua .exam-book-copy h3{font-size:clamp(22px,2vw,30px);line-height:1.5;font-weight:600;letter-spacing:-.5px;margin:0 0 13px;overflow-wrap:anywhere}
#books-tsinghua .exam-book-copy p{font-size:16px;line-height:1.9;color:#666;margin:0;overflow-wrap:anywhere}
#books-tsinghua .exam-book-cover:focus-visible{outline:3px solid #252525;outline-offset:5px}
@media(max-width:1100px) and (min-width:761px){#books-tsinghua .exam-books{gap:28px}
#books-tsinghua .exam-book{grid-template-columns:minmax(0,1fr);gap:15px;padding-bottom:26px}
#books-tsinghua .exam-book-cover{height:290px}
#books-tsinghua .exam-book-copy h3{font-size:25px}
#books-tsinghua .exam-book-copy p{font-size:15px}}
@media(max-width:760px){#books-tsinghua{margin-top:42px;padding-top:24px;border-top-width:4px}
#books-tsinghua .exam-series-heading{margin-bottom:17px}
#books-tsinghua .exam-series-heading>p{font-size:13px;margin-bottom:10px}
#books-tsinghua .exam-series-heading h2{font-size:28px;line-height:1.45;letter-spacing:-.6px}
#books-tsinghua .exam-books{grid-template-columns:minmax(0,1fr);gap:12px}
#books-tsinghua .exam-book{grid-template-columns:minmax(0,.95fr) minmax(0,1.05fr);gap:20px;padding:10px 0 22px}
#books-tsinghua .exam-book-cover{height:clamp(180px,53vw,270px)}
#books-tsinghua .exam-book-copy h3{font-size:22px;line-height:1.55;letter-spacing:-.5px;margin-bottom:10px}
#books-tsinghua .exam-book-copy p{font-size:14px;line-height:1.85}}
@media(max-width:359px){#books-tsinghua .exam-series-heading h2{font-size:25px}
#books-tsinghua .exam-book{gap:14px}
#books-tsinghua .exam-book-copy h3{font-size:20px}
#books-tsinghua .exam-book-copy p{font-size:13px}}
.books-editorial .publisher-emphasis{color:#252525;font-weight:500;background-image:linear-gradient(#FFD100,#FFD100);background-repeat:no-repeat;background-size:100% 2px;background-position:left bottom;padding-bottom:6px;box-decoration-break:clone;-webkit-box-decoration-break:clone;line-height:2}
.books-editorial .book-cover,.books-editorial .exam-book-cover{cursor:default}
.books-editorial .book-cover img,.books-editorial .exam-book-cover img{cursor:default;transition:none}
.books-editorial .book-cover:hover img,.books-editorial .exam-book-cover:hover img{transform:none}
footer.social-footer{display:block;padding:62px var(--gutter) 66px;max-width:1920px;margin:0 auto;background:#fff;border-top:1px solid #ddd;text-align:center}
footer.social-footer h2{font-size:32px;line-height:1.4;font-weight:600;letter-spacing:-.6px;margin:0 0 32px;color:#252525}
footer.social-footer .social-accounts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:32px;max-width:960px;margin:0 auto;align-items:start}
footer.social-footer .social-account{display:flex;flex-direction:column;align-items:center;gap:14px;margin:0;min-width:0}
footer.social-footer figcaption{font-size:15px;font-weight:500;line-height:1.7;color:#252525}
footer.social-footer .social-qr{display:block;width:100%;max-width:210px;height:auto;aspect-ratio:1;overflow:hidden;background:#fff}
@media(max-width:760px){footer.social-footer{padding-top:40px;padding-bottom:42px}
footer.social-footer h2{font-size:28px;margin-bottom:26px}
footer.social-footer .social-accounts{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px 24px;max-width:440px}
footer.social-footer figcaption{font-size:14px}
footer.social-footer .social-qr{max-width:190px}}
@media(max-width:359px){footer.social-footer .social-accounts{column-gap:16px}
footer.social-footer h2{font-size:26px}}
footer.social-footer{padding:36px var(--gutter) 22px;text-align:left}
footer.social-footer .footer-brand-row{display:flex;align-items:center;justify-content:space-between;gap:24px;padding-bottom:26px;border-bottom:1px solid #e2e2e2}
footer.social-footer .footer-brand .wordmark{font-size:24px;font-weight:700;line-height:1.5}
footer.social-footer .footer-brand p{font-size:13px;color:#666;line-height:1.8;margin:7px 0 0;width:auto}
footer.social-footer .footer-top{display:inline-flex;align-items:center;min-height:44px;font-size:13px;color:#666;white-space:nowrap}
footer.social-footer .footer-social-main{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:40px;padding:30px 0}
footer.social-footer .footer-social-main h2{font-size:28px;margin:0;line-height:1.5}
footer.social-footer .social-accounts{grid-template-columns:repeat(4,128px);gap:26px;max-width:none;margin:0}
footer.social-footer .social-account{gap:9px}
footer.social-footer figcaption{font-size:13px}
footer.social-footer .social-qr{width:128px;max-width:128px;height:128px}
footer.social-footer .footer-registration{display:flex;align-items:center;justify-content:center;gap:8px 24px;flex-wrap:wrap;border-top:1px solid #e2e2e2;padding-top:17px;color:#666;font-size:12px;line-height:1.8}
footer.social-footer .footer-registration a{display:inline-flex;align-items:center;gap:6px;font-size:12px;color:#666;min-height:30px}
footer.social-footer .footer-registration img{width:18px;height:20px;object-fit:contain;flex:none;cursor:default}
footer.social-footer .footer-registration a:hover,footer.social-footer .footer-top:hover{text-decoration:underline;text-underline-offset:4px}
@media(max-width:1000px){footer.social-footer .footer-social-main{grid-template-columns:minmax(0,1fr);gap:20px}
footer.social-footer .social-accounts{justify-content:start}
footer.social-footer .footer-social-main h2{font-size:26px}}
@media(max-width:760px){footer.social-footer{padding-top:28px;padding-bottom:20px}
footer.social-footer .footer-brand-row{gap:16px;padding-bottom:22px}
footer.social-footer .footer-social-main{padding:24px 0;gap:20px}
footer.social-footer .social-accounts{width:100%;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px 18px;max-width:340px;margin:0 auto}
footer.social-footer .social-qr{width:120px;max-width:120px;height:120px}
footer.social-footer .social-account{gap:7px}
footer.social-footer .footer-registration{flex-direction:column;gap:5px;padding-top:15px;font-size:11px;text-align:center}
footer.social-footer .footer-registration a{font-size:11px;min-height:30px}}
#follow{scroll-margin-top:calc(var(--header) + 16px)}
#follow:focus-visible{outline:2px solid #252525;outline-offset:-4px}
.contact-dialog{border:0;background:#fff;color:#252525;padding:22px 24px 24px;max-width:380px;width:calc(100% - 32px);max-height:calc(100svh - 40px);overflow:auto;border-radius:4px;margin:auto;box-sizing:border-box}
.contact-dialog::backdrop{background:#0008}
.contact-dialog-heading{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:12px}
.contact-dialog-heading h2{font:600 24px/1.5 MiSans,sans-serif;letter-spacing:-.4px;margin:0}
.contact-dialog-close{display:flex;align-items:center;justify-content:center;border:0;background:#f0f0f0;color:#252525;width:44px;height:44px;font:400 28px/1 MiSans,sans-serif;flex:none;cursor:pointer}
.contact-qr-frame{padding:16px;background:#fff}
.contact-qr-frame img{display:block;width:100%;height:auto;max-width:300px;margin:auto;cursor:default}
body:has(.contact-dialog[open]){overflow:hidden}
@media(max-width:359px){.contact-dialog{padding:18px}
.contact-dialog-heading h2{font-size:22px}
.contact-qr-frame{padding:12px}}
.books-editorial .publisher-emphasis{display:inline-block;position:relative;background:none;padding:0 0 0 15px;color:#252525;font-weight:600;line-height:1.8;box-decoration-break:initial;-webkit-box-decoration-break:initial}
.books-editorial .publisher-emphasis:before{content:'';position:absolute;left:0;top:.2em;bottom:.2em;width:4px;background:#FFD100}
:root{--header:80px}
.site-header{background:#fff}
@media(max-width:760px){:root{--header:104px}}
.books-editorial .question-tiers{max-width:360px;gap:28px}
.books-editorial .tiers-2{max-width:240px}
.books-editorial .question-tiers li{border-top:0;text-align:center;padding-top:12px}
.books-editorial .question-tiers li:after{content:'';position:absolute;top:0;left:50%;transform:translateX(-50%);width:min(100%,84px);height:2px;background:var(--collection-accent)}
.books-editorial .question-tiers li+li:before{left:-20px;width:12px;top:12px;text-align:center}
.author-marketing .credentials>div:first-child{grid-template-columns:80px 1fr}
.author-marketing .credentials>div:first-child dt{white-space:nowrap}
@media(max-width:760px){.books-editorial .question-tiers{max-width:320px;gap:25px}
.books-editorial .tiers-2{max-width:220px}
.books-editorial .question-tiers li{padding-top:10px}
.books-editorial .question-tiers li:after{width:min(100%,72px)}
.books-editorial .question-tiers li+li:before{left:-18.5px;top:10px}
.author-marketing .credentials>div:first-child{grid-template-columns:72px 1fr}}
.books-editorial .question-tiers li{text-align:left}
.books-editorial .question-tiers li:after{left:0;transform:none}
.author-marketing .credentials>div:first-child{grid-template-columns:64px 1fr}
@media(max-width:760px){.author-marketing .credentials>div:first-child{grid-template-columns:56px 1fr}}
.books-editorial{--book-body-height:clamp(188px,16vw,252px);padding-top:64px;padding-bottom:64px}
.books-editorial .books-heading>p{font-size:15px;line-height:1.8;margin-bottom:12px}
.books-editorial #books-title{font-size:clamp(32px,3vw,46px);line-height:1.4;letter-spacing:-.8px}
.books-editorial .collection-summary{grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);column-gap:clamp(32px,5vw,80px);padding:26px 0 28px;border-top-width:4px;align-items:center}
.books-editorial .collection-title h3{font-size:28px}
.books-editorial .collection-title>span{font-size:14px}
.books-editorial .collection-counts{margin-top:18px;gap:20px}
.books-editorial .collection-counts>div{flex-direction:column;align-items:flex-start;gap:4px}
.books-editorial .collection-counts dd{font-size:34px;line-height:1.25}
.books-editorial .collection-counts dt{font-size:13px;line-height:1.6}
.books-editorial .collection-method h4{font-size:16px;line-height:1.7;margin-bottom:14px}
.books-editorial .collection-method>p{font-size:13px;line-height:1.8;margin-top:12px}
.books-editorial .book-list{grid-template-columns:repeat(5,minmax(0,1fr));gap:32px 24px;padding-top:26px}
.books-editorial .collection-junior .book-list{grid-template-columns:repeat(6,minmax(0,1fr));gap:32px 24px}
.books-editorial .book-list li{padding:0 0 20px;min-width:0;min-height:0;border-bottom:1px solid #ddd}
.books-editorial .book-list .book-cover{position:relative;display:block;flex:none;width:100%;height:calc(var(--book-body-height) + 20px);padding:0;margin:0 0 16px;overflow:hidden;cursor:default}
.books-editorial .book-list .book-cover img,
.books-editorial #books-tsinghua .exam-book-cover img{position:absolute;display:block;max-width:none;width:calc(var(--book-body-height) * var(--cover-width-factor,1));height:calc(var(--book-body-height) * var(--cover-height-factor,1));left:calc(50% - var(--book-body-height) * var(--cover-left-factor,.5));top:calc(10px - var(--book-body-height) * var(--cover-top-factor,0));object-fit:fill;transform:none;transition:none;cursor:default}
.books-editorial .book-list .book-copy{min-width:0;padding:0}
.books-editorial .book-list h3{font-size:16px;line-height:1.65;min-height:3.3em;font-weight:500;letter-spacing:0;overflow-wrap:anywhere;margin:0}
.books-editorial .collection-junior .book-list h3{min-height:1.65em}
.books-editorial .book-list p{font-size:13px;line-height:1.8;margin:7px 0 0;min-height:3.6em;overflow-wrap:anywhere;color:#666}
.books-editorial .collection-explore{margin-top:18px;min-height:44px;font-size:14px}
.books-editorial #books-tsinghua{margin-top:72px;padding-top:28px;border-top-width:4px}
.books-editorial #books-tsinghua .exam-series-heading{margin-bottom:28px}
.books-editorial #books-tsinghua .exam-series-heading>p{font-size:15px;margin-bottom:12px}
.books-editorial #books-tsinghua .exam-series-heading h2{font-size:clamp(32px,3vw,46px);line-height:1.4;letter-spacing:-.8px}
.books-editorial #books-tsinghua .exam-books{grid-template-columns:repeat(2,minmax(0,1fr));gap:40px}
.books-editorial #books-tsinghua .exam-book{--book-body-height:clamp(230px,20vw,300px);grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);gap:24px;align-items:center;padding:8px 0 26px}
.books-editorial #books-tsinghua .exam-book-cover{position:relative;display:block;width:100%;height:calc(var(--book-body-height) + 20px);overflow:hidden;cursor:default}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:clamp(22px,1.9vw,28px);line-height:1.5;margin-bottom:12px}
.books-editorial #books-tsinghua .exam-book-copy p{font-size:15px;line-height:1.85}
@media(min-width:1700px){.books-editorial .book-list h3{font-size:17px}
.books-editorial .book-list p{font-size:14px}}
@media(max-width:1279px){.books-editorial .collection-junior .book-list{grid-template-columns:repeat(3,minmax(0,1fr));column-gap:24px}}
@media(min-width:761px) and (max-width:999px){.books-editorial{--book-body-height:210px}
.books-editorial .book-list{grid-template-columns:repeat(3,minmax(0,1fr))}
.books-editorial .collection-summary{column-gap:32px}
.books-editorial .collection-counts{gap:12px}
.books-editorial #books-tsinghua .exam-books{grid-template-columns:minmax(0,1fr);gap:24px}
.books-editorial #books-tsinghua .exam-book{--book-body-height:250px;grid-template-columns:minmax(0,.8fr) minmax(0,1.2fr);gap:32px}}
@media(max-width:760px){.books-editorial{--book-body-height:clamp(146px,44vw,236px);padding-top:38px;padding-bottom:40px}
.books-editorial .books-heading{margin-bottom:26px}
.books-editorial .books-heading>p{font-size:13px;line-height:1.85;margin-bottom:10px;max-width:none}
.books-editorial #books-title{font-size:29px;line-height:1.4;letter-spacing:-.6px}
.books-editorial .collection-summary{grid-template-columns:minmax(0,1fr);gap:24px;padding:21px 0 24px}
.books-editorial .collection-counts{gap:16px;margin-top:16px}
.books-editorial .collection-method h4{font-size:14px;margin-bottom:12px}
.books-editorial .collection-method>p{font-size:13px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px 18px;padding-top:20px}
.books-editorial .book-list .book-cover{height:calc(var(--book-body-height) + 20px);margin-bottom:12px}
.books-editorial .book-list h3{font-size:15px;line-height:1.65;min-height:3.3em}
.books-editorial .collection-junior .book-list h3{min-height:1.65em}
.books-editorial .book-list p{font-size:12px;line-height:1.8;margin-top:6px;min-height:3.6em}
.books-editorial .book-list li{padding-bottom:16px}
.books-editorial .collection-explore{font-size:13px;margin-top:14px}
.books-editorial #books-tsinghua{margin-top:48px;padding-top:24px}
.books-editorial #books-tsinghua .exam-series-heading{margin-bottom:22px}
.books-editorial #books-tsinghua .exam-series-heading>p{font-size:13px;margin-bottom:10px}
.books-editorial #books-tsinghua .exam-series-heading h2{font-size:28px;line-height:1.45;letter-spacing:-.6px}
.books-editorial #books-tsinghua .exam-books{grid-template-columns:minmax(0,1fr);gap:20px}
.books-editorial #books-tsinghua .exam-book{--book-body-height:clamp(150px,42vw,220px);grid-template-columns:minmax(0,.95fr) minmax(0,1.05fr);gap:20px;padding:0 0 22px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:22px;line-height:1.55;margin-bottom:10px}}
@media(max-width:359px){.books-editorial #books-title{font-size:27px}
.books-editorial #books-tsinghua .exam-series-heading h2{font-size:25px}
.books-editorial #books-tsinghua .exam-book{gap:14px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:20px}
.books-editorial #books-tsinghua .exam-book-copy p{font-size:13px}}
.books-editorial .book-list h3,.books-editorial .collection-junior .book-list h3{min-height:0}
.books-editorial .book-list p{min-height:0}
footer.social-footer{padding-top:38px;padding-bottom:22px}
footer.social-footer .footer-brand-row{padding-bottom:24px}
footer.social-footer .footer-social-main{grid-template-columns:minmax(220px,1fr) auto;gap:32px;padding:28px 0;align-items:center}
footer.social-footer .footer-social-main h2{font-size:28px;line-height:1.5;margin:0}
footer.social-footer .social-accounts{grid-template-columns:repeat(4,152px);gap:20px;margin:0;max-width:none}
footer.social-footer .social-account{gap:12px;align-items:center}
footer.social-footer figcaption{font-size:14px;line-height:1.6;font-weight:500}
footer.social-footer .social-qr-frame{display:flex;align-items:center;justify-content:center;box-sizing:border-box;width:152px;height:152px;padding:11px;border:1px solid #e2e2e2;background:#fff}
footer.social-footer .social-qr{width:128px;height:128px;max-width:128px;flex:none}
footer.social-footer .footer-registration{padding-top:18px;gap:8px 22px;line-height:1.8}
footer.social-footer .footer-registration a{min-height:32px}
.site-header a:focus-visible,.site-header button:focus-visible,.hero-actions a:focus-visible,.quiet-link:focus-visible,footer.social-footer a:focus-visible,.contact-dialog button:focus-visible{outline:2px solid #252525;outline-offset:4px}
.contact-dialog{border:1px solid #bdbdbd;padding:24px;border-radius:4px}
.contact-dialog-heading{margin-bottom:14px}
.contact-dialog-close{border-radius:4px}
.contact-qr-frame{padding:12px}
@media(hover:hover){.quiet-link:hover{text-decoration:underline;text-underline-offset:4px}
.contact-dialog-close:hover{background:#e4e4e4}}
@media(max-width:1100px){footer.social-footer .footer-social-main{grid-template-columns:minmax(0,1fr);gap:20px}}
@media(max-width:760px){footer.social-footer{padding-top:30px;padding-bottom:20px}
footer.social-footer .footer-brand-row{padding-bottom:22px}
footer.social-footer .footer-social-main{padding:24px 0;gap:22px}
footer.social-footer .footer-social-main h2{font-size:24px}
footer.social-footer .social-accounts{width:100%;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px 16px;max-width:320px;margin:0 auto}
footer.social-footer .social-account{gap:10px}
footer.social-footer .social-qr-frame{width:132px;height:132px;padding:5px}
footer.social-footer .social-qr{width:120px;height:120px;max-width:120px}
footer.social-footer .footer-registration{gap:5px;padding-top:16px}}
:root{--vi-yellow:#FFD100;--vi-orange:#FF5800;--vi-blue:#0065BD;--vi-green:#00AF3F;--vi-ink:#252525;--vi-muted:#666666;--vi-line:#BDBDBD;--vi-paper:#F0F0F0;--yellow:var(--vi-yellow);--orange:var(--vi-orange);--blue:var(--vi-blue)}
.site-header{background:#fff;border-bottom:1px solid var(--vi-line)}
.site-header nav a:after{height:3px;background:var(--vi-yellow)}
.site-header .header-cta{border-radius:4px}
.site-header .header-cta:active,#home .pill:active{background:#666}
.mathematics.page-section{border-top:1px solid var(--vi-line);border-bottom:1px solid var(--vi-line)}
.books-editorial{padding-top:clamp(64px,6vw,96px);padding-bottom:clamp(64px,6vw,96px);background:#F8F8F8}
.books-editorial .books-heading{margin-bottom:40px}
.books-editorial .books-heading>p,.books-editorial #books-tsinghua .exam-series-heading>p{font-size:15px;line-height:1.8;margin-bottom:16px}
.books-editorial #books-title,.books-editorial #books-tsinghua .exam-series-heading h2{font-size:clamp(34px,3vw,44px);line-height:1.35;letter-spacing:-.8px}
.books-editorial .publisher-emphasis{padding-left:18px;font-weight:600}
.books-editorial .publisher-emphasis:before{width:4px;background:var(--vi-yellow)}
.books-editorial .book-collection{--collection-accent:var(--vi-blue)}
.books-editorial .collection-junior{--collection-accent:var(--vi-orange)}
.books-editorial .collection-summary{grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);column-gap:clamp(32px,5vw,80px);padding:30px 0 32px;border-top:6px solid var(--collection-accent);border-bottom:1px solid var(--vi-line)}
.books-editorial .collection-title{gap:16px;align-items:baseline}
.books-editorial .collection-title h3{font-size:30px;line-height:1.4;letter-spacing:-.5px}
.books-editorial .collection-counts{margin-top:22px;gap:24px}
.books-editorial .collection-counts dd{font-size:40px;line-height:1.2;letter-spacing:-1px}
.books-editorial .collection-counts dt{font-size:14px;line-height:1.6}
.books-editorial .collection-method h4{font-size:16px;line-height:1.7;margin-bottom:18px}
.books-editorial .question-tiers{gap:28px}
.books-editorial .question-tiers li{font-size:23px;line-height:1.45;padding-top:13px}
.books-editorial .question-tiers li:after{height:3px;background:var(--collection-accent)}
.books-editorial .question-tiers li+li:before{top:13px}
.books-editorial .collection-method>p{font-size:14px;line-height:1.8;margin-top:16px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{row-gap:36px;column-gap:24px;padding-top:30px}
.books-editorial .book-list li{padding-bottom:24px;border-bottom-color:#D5D5D5}
.books-editorial .book-list .book-cover{margin-bottom:18px}
.books-editorial .book-list h3{font-size:17px;line-height:1.65;font-weight:500}
.books-editorial .book-list p{font-size:14px;line-height:1.8;margin-top:8px}
.books-editorial .collection-explore{font-size:14px;min-height:44px;margin-top:22px;gap:18px}
.books-editorial .junior-books-group{margin-top:80px}
.books-editorial #books-tsinghua{margin-top:80px;padding-top:32px;border-top:6px solid var(--vi-blue)}
.books-editorial #books-tsinghua .exam-books{gap:40px}
.books-editorial #books-tsinghua .exam-book{padding-bottom:28px;border-bottom-color:#D5D5D5}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:clamp(24px,2vw,30px);line-height:1.45}
.books-editorial #books-tsinghua .exam-book-copy p{font-size:16px;line-height:1.8}
footer.social-footer{padding-top:48px;padding-bottom:24px;border-top:1px solid var(--vi-line)}
footer.social-footer .footer-brand-row{padding-bottom:28px;border-bottom-color:var(--vi-line)}
footer.social-footer .footer-brand .wordmark{font-size:26px;letter-spacing:-.4px}
footer.social-footer .footer-brand p{font-size:14px;line-height:1.8;margin-top:8px}
footer.social-footer .footer-top{font-size:13px}
footer.social-footer .footer-social-main{grid-template-columns:minmax(220px,1fr) auto;gap:40px;padding:36px 0;align-items:start}
footer.social-footer .footer-social-main h2{font-size:30px;line-height:1.4;margin:0;padding-top:1px}
footer.social-footer .social-accounts{gap:24px}
footer.social-footer .social-account{gap:14px}
footer.social-footer figcaption{font-size:14px;line-height:1.5}
footer.social-footer .social-qr-frame{border-color:#D5D5D5;border-radius:0}
footer.social-footer .footer-registration{border-top-color:var(--vi-line);padding-top:20px;gap:8px 24px}
.contact-dialog{border:1px solid var(--vi-line);border-radius:4px;box-shadow:none}
.contact-dialog-heading h2{font-size:26px;font-weight:600}
.contact-dialog-close{border:1px solid #D5D5D5;border-radius:4px}
.books-editorial a:focus-visible,footer.social-footer a:focus-visible,.contact-dialog button:focus-visible{outline:2px solid var(--vi-ink);outline-offset:4px}
@media(max-width:1100px){footer.social-footer .footer-social-main{grid-template-columns:1fr;gap:24px}
.books-editorial .collection-summary{column-gap:32px}}
@media(max-width:760px){.books-editorial{padding-top:44px;padding-bottom:48px}
.books-editorial #books-title,.books-editorial #books-tsinghua .exam-series-heading h2{font-size:30px;line-height:1.4;letter-spacing:-.6px}
.books-editorial .collection-summary{grid-template-columns:1fr;gap:28px;padding:24px 0 28px;border-top-width:5px}
.books-editorial .collection-title h3{font-size:26px}
.books-editorial .collection-counts{margin-top:18px;gap:16px}
.books-editorial .collection-counts dd{font-size:34px}
.books-editorial .collection-method h4{font-size:14px;margin-bottom:14px}
.books-editorial .question-tiers li{font-size:21px;padding-top:12px}
.books-editorial .question-tiers li+li:before{top:12px}
.books-editorial .collection-method>p{font-size:13px;margin-top:14px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{gap:28px 18px;padding-top:24px}
.books-editorial .book-list .book-cover{margin-bottom:14px}
.books-editorial .book-list p{font-size:13px;line-height:1.8;margin-top:7px}
.books-editorial .book-list li{padding-bottom:20px}
.books-editorial .collection-explore{font-size:13px;margin-top:18px}
.books-editorial .junior-books-group{margin-top:52px}
.books-editorial #books-tsinghua{margin-top:52px;padding-top:28px;border-top-width:5px}
.books-editorial #books-tsinghua .exam-books{gap:24px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:22px}
footer.social-footer{padding-top:32px;padding-bottom:20px}
footer.social-footer .footer-brand-row{padding-bottom:24px;gap:14px}
footer.social-footer .footer-brand .wordmark{font-size:22px}
footer.social-footer .footer-top{font-size:12px}
footer.social-footer .social-accounts{gap:26px 16px;max-width:320px;margin:0 auto}
footer.social-footer .footer-registration{gap:5px;padding-top:18px}}
@media(max-width:359px){.books-editorial #books-title,.books-editorial #books-tsinghua .exam-series-heading h2{font-size:27px}}
@media(max-width:760px){.books-editorial{--book-body-height:clamp(134px,38vw,208px);padding-top:40px;padding-bottom:44px}
.books-editorial .books-heading{margin-bottom:24px}
.books-editorial #books-title,.books-editorial #books-tsinghua .exam-series-heading h2{font-size:28px;line-height:1.4;letter-spacing:-.5px}
.books-editorial .books-heading>p,.books-editorial #books-tsinghua .exam-series-heading>p{font-size:13px;line-height:1.8;margin-bottom:12px}
.books-editorial .collection-summary{gap:22px;padding:20px 0 24px;border-top-width:4px}
.books-editorial .collection-title h3{font-size:25px}
.books-editorial .collection-counts{margin-top:16px;gap:14px}
.books-editorial .collection-counts dd{font-size:32px}
.books-editorial .collection-method h4{font-size:14px;line-height:1.7;margin-bottom:12px}
.books-editorial .question-tiers li{font-size:20px;padding-top:11px}
.books-editorial .question-tiers li+li:before{top:11px}
.books-editorial .collection-method>p{font-size:13px;margin-top:12px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px 16px;padding-top:22px}
.books-editorial .book-list .book-cover{margin-bottom:12px;height:calc(var(--book-body-height) + 20px)}
.books-editorial .book-list li{padding-bottom:18px}
.books-editorial .book-list h3{font-size:15px;line-height:1.6;letter-spacing:0;overflow-wrap:normal}
.books-editorial .book-title-unit{display:inline-block;vertical-align:top;white-space:nowrap;max-width:100%}
.books-editorial .book-list p{font-size:12.5px;line-height:1.8;margin-top:7px;overflow-wrap:anywhere}
.books-editorial .collection-explore{font-size:13px;margin-top:16px;min-height:44px}
.books-editorial .junior-books-group{margin-top:44px}
.books-editorial #books-tsinghua{margin-top:44px;padding-top:24px;border-top-width:4px}
.books-editorial #books-tsinghua .exam-series-heading{margin-bottom:24px}
.books-editorial #books-tsinghua .exam-books{gap:22px}
.books-editorial #books-tsinghua .exam-book{--book-body-height:clamp(144px,38vw,190px);grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);gap:16px;padding:0 0 22px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:20px;line-height:1.55;margin-bottom:10px}
.books-editorial #books-tsinghua .exam-book-copy p{font-size:14px;line-height:1.85}}
@media(max-width:359px){.books-editorial #books-title,.books-editorial #books-tsinghua .exam-series-heading h2{font-size:26px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{column-gap:14px}
.books-editorial .book-list h3{font-size:14px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:19px}}
.author-marketing .author-photo{background:#F0F0F0}
.author-marketing .author-photo img{display:block;width:100%;height:auto;aspect-ratio:4/5;max-height:760px;
 object-fit:cover;object-position:60% 42%;}
footer.social-footer .footer-brand-row{align-items:flex-start;gap:24px;padding-bottom:28px}
footer.social-footer .footer-top{display:inline-flex;align-items:center;min-height:44px;white-space:nowrap}
footer.social-footer .footer-social-main{grid-template-columns:minmax(220px,1fr) auto;gap:32px;
 padding:40px 0;align-items:start;}
footer.social-footer .footer-social-main h2{padding-top:0;line-height:1.4}
footer.social-footer .social-accounts{align-items:start;gap:24px;justify-content:end}
footer.social-footer .social-account{margin:0;gap:16px;align-items:center}
footer.social-footer .social-account figcaption{display:flex;align-items:center;justify-content:center;min-height:42px;
 margin:0;font-weight:500;line-height:1.5;}
footer.social-footer .footer-registration{justify-content:flex-start;align-items:center;gap:8px 24px;padding-top:20px;line-height:1.8;}
@media(max-width:1100px){footer.social-footer .footer-social-main{grid-template-columns:1fr;gap:20px}
footer.social-footer .social-accounts{justify-content:start}}
@media(max-width:760px){.author-marketing .author-photo img{height:auto;aspect-ratio:4/5;max-height:none;object-position:60% 42%}
footer.social-footer .footer-brand-row{gap:12px;padding-bottom:24px}
footer.social-footer .footer-top{align-self:flex-start;min-height:44px}
footer.social-footer .footer-social-main{padding:28px 0 32px;gap:20px}
footer.social-footer .footer-social-main h2{font-size:26px;line-height:1.4}
footer.social-footer .social-accounts{max-width:320px;margin:0 auto;gap:24px 16px;justify-content:normal}
footer.social-footer .social-account figcaption{min-height:24px;font-size:14px}
footer.social-footer .footer-registration{align-items:flex-start;text-align:left;gap:4px;padding-top:18px;}
footer.social-footer .footer-registration a{min-height:36px;max-width:100%}}
.author-marketing .author-copy > #author-title::before{content:"";display:block;width:52px;height:4px;
 margin-bottom:16px;background:#FF5800;}
.books-editorial #junior-book-list .book-copy p{color:#252525;font-weight:500}
@media(max-width:760px){:root{--header:96px}
.site-header .header-inner{height:100%;padding-top:7px;padding-bottom:0;
  grid-template-rows:44px 44px;align-content:start;align-items:center;row-gap:0;}
.site-header .wordmark{line-height:1.25;align-self:center}
.site-header .header-cta{position:relative;align-self:center;justify-self:end;margin:0;
  width:auto;min-width:88px;min-height:34px;height:34px;
  padding:7px 14px;font-size:12px;line-height:20px;letter-spacing:0;
  display:inline-flex;align-items:center;justify-content:center;}
.site-header .header-cta::before{content:"";position:absolute;inset:-5px 0}
.site-header nav{height:44px;padding-top:0;align-items:center}
.site-header nav a{display:inline-flex;align-items:center;min-height:44px;padding:0;line-height:20px}
.site-header nav a::after{bottom:2px}}
.books-editorial .collection-method h4{margin-bottom:18px}
.books-editorial .collection-method .question-tiers{max-width:440px;gap:30px}
.books-editorial .collection-method .tiers-2{max-width:284px}
.books-editorial .collection-method .question-tiers li{display:flex;align-items:center;gap:9px;border:0;padding:0;font-size:23px;line-height:1.6;white-space:nowrap}
.books-editorial .collection-method .question-tiers li::after{content:none}
.books-editorial .collection-method .question-tiers li+li::before{content:'→';left:-25px;top:0;width:20px;font-size:19px;line-height:36.8px;color:#999;font-weight:400}
.books-editorial .tier-steps{display:inline-flex;align-items:flex-end;gap:3px;height:24px;flex:none}
.books-editorial .tier-steps i{display:block;width:5px;height:8px;background:#BDBDBD}
.books-editorial .tier-steps i:nth-child(2){height:15px}
.books-editorial .tier-steps i:nth-child(3){height:22px}
.books-editorial .question-tiers li .tier-steps i:first-child,
.books-editorial .question-tiers li:nth-child(n+2) .tier-steps i:nth-child(2),
.books-editorial .question-tiers li:nth-child(3) .tier-steps i:nth-child(3){background:var(--collection-accent)}
.books-editorial .collection-method>p.method-description{max-width:440px;margin-top:20px;line-height:1.85;text-wrap:wrap}
.books-editorial .method-guide{display:block;color:#252525;font-size:15px;font-weight:500}
.books-editorial .method-phrase{white-space:nowrap}
.books-editorial .method-motto{display:block;margin-top:6px;color:#666;font-size:13px;text-align:right}
@media(max-width:1000px) and (min-width:761px){.books-editorial .collection-method .question-tiers{gap:24px}
.books-editorial .collection-method .question-tiers li{font-size:20px;gap:6px}
.books-editorial .collection-method .question-tiers li+li::before{left:-22px;line-height:32px}}
@media(max-width:760px){.books-editorial .collection-method h4{margin-bottom:16px}
.books-editorial .collection-method .question-tiers{max-width:380px;gap:25px}
.books-editorial .collection-method .tiers-2{max-width:246px}
.books-editorial .collection-method .question-tiers li{font-size:20px;gap:7px}
.books-editorial .collection-method .question-tiers li+li::before{left:-22px;line-height:32px;font-size:17px}
.books-editorial .tier-steps{gap:2px;height:22px}
.books-editorial .tier-steps i{width:4px}
.books-editorial .collection-method>p.method-description{margin-top:16px;max-width:380px}
.books-editorial .method-guide{font-size:14px}
.books-editorial .method-motto{font-size:12px;margin-top:5px}}
.books-editorial .collection-method .question-tiers{--tier-arrow-gap:clamp(8px,2.5vw,24px);
 --tier-inner-gap:9px;
 display:flex;align-items:center;gap:var(--tier-arrow-gap);}
.books-editorial .collection-method .question-tiers li{flex:0 0 auto;gap:var(--tier-inner-gap);}
.books-editorial .collection-method .question-tiers li+li::before{position:static;display:block;flex:0 0 auto;align-self:center;
 inset:auto;transform:none;width:1em;height:auto;padding:0;
 margin:0 calc(var(--tier-arrow-gap) - var(--tier-inner-gap)) 0 0;
 line-height:1;text-align:center;}
@media(max-width:1000px) and (min-width:761px){.books-editorial .collection-method .question-tiers{--tier-inner-gap:6px}}
@media(max-width:760px){.books-editorial .collection-method .question-tiers{--tier-inner-gap:7px}}
.books-editorial .collection-junior .question-tiers .tier-steps{transform:translateY(-4px)}
@media(max-width:700px){.learning-network:not(.node-detail-mode) .network-heading{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;
  column-gap:8px;row-gap:8px;}
.learning-network:not(.node-detail-mode) .network-heading-copy{display:contents}
.learning-network:not(.node-detail-mode) .network-heading-copy h2{grid-column:1;grid-row:1;margin:0;
  font-size:clamp(16px,4.6vw,22px);line-height:1.4;letter-spacing:-.5px;white-space:nowrap;}
.learning-network:not(.node-detail-mode) .network-heading-actions{grid-column:2;grid-row:1;align-self:center;justify-self:end;
  margin:0;padding:0;}
.learning-network:not(.node-detail-mode) .network-heading-actions .independent-link{min-height:44px;padding:0 8px;font-size:11px;}
.learning-network:not(.node-detail-mode) .network-heading .network-purpose{grid-column:1/-1;grid-row:2;margin:0;}}
.books-editorial .collection-high .question-tiers .tier-steps{transform:translateY(-3px)}
body:has(#home.hero-particle){background:#fff}
#home.hero-particle{--intro-white:#f5f5f7;--intro-silver:#b9bdc5;
 position:relative;isolation:isolate;max-width:none;width:100%;
 min-height:calc(100svh - var(--header));padding:0 var(--gutter);
 display:flex;flex-direction:column;background:#08090b;color:var(--intro-white);}
#home.hero-particle .particle-stage{position:relative;display:grid;place-items:center;flex:1;
 min-height:560px;padding:48px 0 36px;}
#home.hero-particle .particle-copy{position:relative;z-index:1;width:100%;text-align:center}
#home.hero-particle .particle-kicker{font-size:16px;font-weight:500;letter-spacing:.12em;color:#b9bdc5;margin:0 0 24px}
#home.hero-particle h1{margin:0;font-size:clamp(76px,9vw,144px);font-weight:600;line-height:1.16;letter-spacing:-.045em;white-space:normal}
#home.hero-particle h1 span{display:block}
#home.hero-particle h1 span+span{margin-top:4px}
#home.hero-particle .particle-description{margin:30px auto 0;font-size:20px;line-height:1.8;font-weight:400;color:#b9bdc5;max-width:36em;text-wrap:pretty}
#home.hero-particle .particle-motto{display:block;margin-top:7px;font-size:23px;font-weight:500;color:#f5f5f7}
#home.hero-particle .particle-actions{position:relative;z-index:3;display:flex;justify-content:center;padding:0 0 38px}
#home.hero-particle .particle-actions .pill{border-radius:4px;background:#f5f5f7;color:#252525;font-size:16px;font-weight:500;min-height:48px;min-width:164px;padding:12px 24px}
#home.hero-particle .particle-actions .pill:hover{background:#d9dce2}
#home.hero-particle a:focus-visible{outline:2px solid #fff;outline-offset:5px}
#home.hero-particle .particle-footer{position:relative;z-index:3;display:flex;align-items:center;justify-content:space-between;gap:24px;border-top:1px solid #2b2e34;padding:22px 0 24px}
#home.hero-particle .particle-footer p{font-size:12px;line-height:1.8;color:#969ca6}
#home.hero-particle .particle-footer strong{font-weight:500;color:#d4d7dc}
#home.hero-particle .particle-down{display:flex;align-items:center;gap:20px;min-height:44px;font-size:12px;color:#d4d7dc;white-space:nowrap}
#home.hero-particle .particle-down svg{width:20px;height:30px;flex:none}
#home.hero-particle .particle-canvas{position:absolute;inset:0;width:100%;height:100%;z-index:2;pointer-events:none;display:none}
#home.hero-particle .particle-brand{display:none;position:absolute;inset:0;align-items:center;justify-content:center;margin:0;font-size:clamp(36px,8.4vw,116px);font-weight:600;letter-spacing:0;line-height:1.2;color:#f5f5f7}
#home.hero-particle .particle-brand sup{font-size:.3em;align-self:auto;position:relative;top:-.9em;margin-left:.18em;line-height:1}
.particle-intro-pending #home.hero-particle .particle-copy{opacity:0}
.particle-intro-pending #home.hero-particle .particle-brand{display:flex}
.particle-intro-pending #home.hero-particle[data-intro-state="running"] .particle-brand{display:none}
.particle-intro-pending #home.hero-particle[data-intro-state="running"] .particle-canvas{display:block}
body.particle-header-dark .site-header{background:#08090b;border-bottom-color:#25282d;color:#f5f5f7}
body.particle-header-dark .site-header .header-cta{background:#f5f5f7;color:#252525}
body.particle-header-dark .site-header nav a:after{background:#c6cbd2}
body.particle-header-dark .site-header :focus-visible{outline-color:#fff}
@media(min-width:761px) and (max-height:800px){#home.hero-particle .particle-stage{min-height:430px;padding-top:30px;padding-bottom:26px}
#home.hero-particle h1{font-size:clamp(70px,7.8vw,112px)}
#home.hero-particle .particle-kicker{margin-bottom:16px}
#home.hero-particle .particle-description{margin-top:22px}
#home.hero-particle .particle-actions{padding-bottom:24px}
#home.hero-particle .particle-footer{padding-top:14px;padding-bottom:14px}}
@media(max-width:760px){#home.hero-particle .particle-stage{min-height:360px;padding:36px 0 28px}
#home.hero-particle .particle-kicker{font-size:13px;letter-spacing:.08em;margin-bottom:24px}
#home.hero-particle h1{font-size:clamp(48px,12.8vw,82px);line-height:1.18;letter-spacing:-.04em}
#home.hero-particle h1 span+span{margin-top:7px}
#home.hero-particle .particle-description{font-size:15px;line-height:1.85;margin-top:26px;max-width:24em}
#home.hero-particle .particle-motto{font-size:18px;margin-top:10px}
#home.hero-particle .particle-actions{padding-bottom:28px}
#home.hero-particle .particle-actions .pill{min-height:44px;min-width:146px;font-size:14px;padding:10px 20px}
#home.hero-particle .particle-footer{gap:16px;padding:16px 0}
#home.hero-particle .particle-footer p{font-size:10px}
#home.hero-particle .particle-down{font-size:11px;gap:10px}}
@media(prefers-reduced-motion:reduce){.particle-intro-pending #home.hero-particle .particle-copy{opacity:1!important}
#home.hero-particle .particle-brand,#home.hero-particle .particle-canvas{display:none!important}}
#home.hero-particle .particle-brand{visibility:hidden}
#home.hero-particle{justify-content:center;
 padding:56px var(--gutter) 64px;}
#home.hero-particle .particle-composition{width:100%;max-width:1040px;margin:0 auto;}
#home.hero-particle .particle-stage{flex:none;min-height:480px;padding:24px 0;}
#home.hero-particle .particle-copy{width:100%}
#home.hero-particle .particle-kicker{font-size:15px;font-weight:400;letter-spacing:.06em;margin-bottom:26px;}
#home.hero-particle h1{font-size:clamp(76px,7.6vw,112px);
 font-weight:600;line-height:1.18;letter-spacing:-.035em;}
#home.hero-particle h1 span+span{margin-top:5px}
#home.hero-particle .particle-description{width:fit-content;max-width:calc(100% - 8em);
 margin:32px auto 0;font-size:19px;line-height:1.85;
 text-align:left;text-wrap:pretty;}
#home.hero-particle .particle-description>span:first-child{display:block}
#home.hero-particle .particle-motto{display:block;margin-top:10px;margin-right:-4em;
 text-align:right;white-space:nowrap;
 font-size:inherit;font-weight:400;color:#d4d7dc;}
#home.hero-particle .particle-actions{justify-content:center;align-items:center;gap:28px;
 margin-top:30px;padding:0;}
#home.hero-particle .particle-actions .pill{gap:14px;min-width:160px;min-height:48px;
 padding:12px 22px;font-size:15px;line-height:24px;font-weight:500;}
#home.hero-particle .particle-actions .pill svg{display:block;width:14px;height:20px;flex:none;}
#home.hero-particle .particle-action-note{margin:0;font-size:13px;line-height:1.8;color:#aeb3bc;text-align:left;}
#home.hero-particle .particle-action-note strong{font-weight:400;color:#c5c9d0}
@media(min-width:761px) and (max-height:800px){#home.hero-particle{padding-top:32px;padding-bottom:40px}
#home.hero-particle .particle-stage{min-height:380px;padding:16px 0}
#home.hero-particle h1{font-size:clamp(68px,7.2vw,96px)}
#home.hero-particle .particle-kicker{margin-bottom:22px}
#home.hero-particle .particle-description{margin-top:26px;font-size:18px}
#home.hero-particle .particle-actions{margin-top:24px;padding:0}}
@media(max-width:760px){#home.hero-particle{padding-top:32px;padding-bottom:36px}
#home.hero-particle .particle-composition{max-width:520px}
#home.hero-particle .particle-stage{min-height:350px;padding:12px 0}
#home.hero-particle .particle-kicker{font-size:13px;font-weight:400;margin-bottom:24px;letter-spacing:.06em;}
#home.hero-particle h1{font-size:clamp(46px,12.4vw,60px);line-height:1.2;letter-spacing:-.03em;}
#home.hero-particle h1 span+span{margin-top:5px}
#home.hero-particle .particle-description{width:fit-content;max-width:min(100%,23em);
  margin-top:28px;font-size:15px;line-height:1.85;}
#home.hero-particle .particle-motto{margin-top:10px;margin-right:0;font-size:16px;font-weight:400;}
#home.hero-particle .particle-actions{flex-direction:column;gap:16px;margin-top:24px;padding:0;}
#home.hero-particle .particle-actions .pill{width:auto;min-width:150px;min-height:44px;
  padding:10px 18px;font-size:14px;line-height:24px;gap:12px;}
#home.hero-particle .particle-action-note{text-align:center;font-size:13px;line-height:1.75;}}
@media(max-width:760px) and (max-height:650px){#home.hero-particle{padding-top:20px;padding-bottom:24px}
#home.hero-particle .particle-stage{min-height:300px;padding:8px 0}
#home.hero-particle h1{font-size:44px}
#home.hero-particle .particle-kicker{margin-bottom:18px}
#home.hero-particle .particle-description{margin-top:22px}
#home.hero-particle .particle-actions{margin-top:18px;gap:12px}}
#home.hero-particle{--title-old-size:clamp(76px,7.6vw,112px);
 --title-size:clamp(76px,9vw,144px);
 --title-two-lines:2.36;
 --stage-old-min:480px;
 --stage-old-top:24px;
 --title-old-height:calc(var(--title-old-size) * var(--title-two-lines) + 5px);
 --title-new-height:calc(var(--title-size) * var(--title-two-lines) + 5px);
 --title-lift:calc(var(--title-new-height) - var(--title-old-height));}
#home.hero-particle .particle-title-slot{position:relative;width:100%;height:var(--title-old-height);}
#home.hero-particle .particle-title-slot h1{position:absolute;left:0;bottom:0;width:100%;margin:0;
 font-size:var(--title-size);}
#home.hero-particle .particle-kicker{transform:translateY(calc(0px - var(--title-lift)));}
#home.hero-particle .particle-stage{margin-top:calc(0px - var(--title-lift));
 min-height:calc(var(--stage-old-min) + var(--title-lift));
 padding-top:calc(var(--stage-old-top) + var(--title-lift));}
@media(min-width:761px) and (max-height:800px){#home.hero-particle{--title-old-size:clamp(68px,7.2vw,96px);
  --title-size:clamp(70px,7.8vw,112px);
  --stage-old-min:380px;
  --stage-old-top:16px;}}
@media(max-width:760px){#home.hero-particle{--title-old-size:clamp(46px,12.4vw,60px);
  --title-size:clamp(48px,12.8vw,82px);
  --title-two-lines:2.4;
  --stage-old-min:350px;
  --stage-old-top:12px;}}
@media(max-width:760px) and (max-height:650px){#home.hero-particle{--title-old-size:44px;
  --stage-old-min:300px;
  --stage-old-top:8px;}}
.books-editorial .collection-method .type-branch{--branch-line:#BDBDBD;
 width:100%;max-width:440px;margin:24px 0 26px;}
.books-editorial .type-branch .branch-root{margin:0;text-align:center;font-size:15px;line-height:1.6;
 font-weight:400;color:#666666;}
.books-editorial .type-branch .branch-root::after{content:"";display:block;width:1px;height:22px;
 margin:10px auto 0;background:var(--branch-line);}
.books-editorial .type-branch .branch-tiers{--branch-count:3;
 position:relative;display:grid;grid-template-columns:repeat(var(--branch-count),minmax(0,1fr));
 list-style:none;margin:0;padding:0;gap:0;}
.books-editorial .type-branch.branch-two .branch-tiers{--branch-count:2;width:90%;margin-right:auto;margin-left:auto;}
.books-editorial .type-branch .branch-tiers::before{content:"";position:absolute;top:0;
 left:calc(50% / var(--branch-count));right:calc(50% / var(--branch-count));
 height:1px;background:var(--branch-line);}
.books-editorial .type-branch .branch-tiers li{position:relative;display:flex;flex-direction:column;align-items:center;
 min-width:0;margin:0;padding:26px 0 0;border:0;}
.books-editorial .type-branch .branch-tiers li::before{content:"";position:absolute;top:0;left:calc(50% - .5px);
 width:1px;height:27px;background:var(--branch-line);}
.books-editorial .type-branch .branch-node{position:relative;display:block;width:10px;height:10px;
 box-sizing:border-box;border:1.5px solid var(--collection-accent);
 border-radius:50%;background:#F8F8F8;margin-bottom:12px;flex:none;}
.books-editorial .type-branch .branch-name{font-size:23px;line-height:1.5;font-weight:500;color:#252525;white-space:nowrap;}
@media(max-width:1000px) and (min-width:761px){.books-editorial .type-branch .branch-name{font-size:20px}}
@media(max-width:760px){.books-editorial .collection-method .type-branch{max-width:380px;margin-top:22px;margin-bottom:24px;}
.books-editorial .type-branch .branch-root{font-size:14px}
.books-editorial .type-branch .branch-root::after{height:20px;margin-top:8px}
.books-editorial .type-branch .branch-tiers li{padding-top:23px}
.books-editorial .type-branch .branch-tiers li::before{height:24px}
.books-editorial .type-branch .branch-node{width:9px;height:9px;margin-bottom:10px}
.books-editorial .type-branch .branch-name{font-size:20px}}
.books-editorial .collection-method h4{max-width:440px;margin:0 0 26px;
 color:#252525;font-size:clamp(22px,2vw,26px);
 line-height:1.5;font-weight:600;letter-spacing:0;}
.books-editorial .collection-method .type-branch{margin-top:28px;margin-bottom:30px}
.books-editorial .collection-method .type-branch .branch-root{font-size:18px;line-height:1.6;font-weight:500;}
.books-editorial .collection-method .type-branch .branch-name{font-size:22px;line-height:1.5;font-weight:500;}
.books-editorial .collection-method .method-guide{font-size:18px;line-height:1.8;font-weight:400;}
.books-editorial .collection-method .method-motto{margin-top:10px;font-size:14px;line-height:1.8;font-weight:400;}
@media(min-width:761px) and (max-width:1000px){.books-editorial .collection-method h4{font-size:22px}
.books-editorial .collection-method .method-guide{font-size:16px}}
@media(max-width:760px){.books-editorial .collection-method h4{max-width:380px;font-size:clamp(18px,5vw,22px);
  line-height:1.55;margin-bottom:24px;}
.books-editorial .collection-method .type-branch{margin-top:26px;margin-bottom:26px}
.books-editorial .collection-method .type-branch .branch-root{font-size:16px}
.books-editorial .collection-method .method-guide{font-size:15.5px;line-height:1.85}
.books-editorial .collection-method .method-motto{font-size:13px;margin-top:9px}}
@font-face{font-family:MiSans;src:url("/20261101-v122/assets/20261101-beabbf02c122db99.woff") format("woff");font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:MiSans;src:url("/20261101-v122/assets/20261101-97dc0adea1aee00b.woff") format("woff");font-weight:500;font-style:normal;font-display:swap}
@font-face{font-family:MiSans;src:url("/20261101-v122/assets/20261101-9be1c7875ce532c2.woff") format("woff");font-weight:600;font-style:normal;font-display:swap}
@font-face{font-family:MiSans;src:url("/20261101-v122/assets/20261101-ebf11c20d417b8d3.woff") format("woff");font-weight:700;font-style:normal;font-display:swap}
:root{--ui-ink:#252525;--ui-muted:#666666;--ui-rule:#BDBDBD;
 --ui-yellow:#FFD100;--ui-orange:#FF5800;--ui-blue:#0065BD;--ui-green:#00AF3F;
 --ui-title:clamp(42px,3vw,48px);--ui-group:clamp(28px,2.1vw,32px);
 --ui-number:clamp(48px,3.6vw,56px);--ui-body:16px;--ui-note:14px;
 --ui-section-space:clamp(72px,5vw,88px);}
.vi-arrow{display:inline-block;width:20px;height:20px;flex:none;vertical-align:middle;overflow:visible}
.vi-arrow path{stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;fill:none}
@media(max-width:760px){:root{--ui-title:clamp(28px,7.6vw,32px);--ui-group:24px;
 --ui-number:clamp(34px,9.2vw,40px);--ui-body:15px;--ui-note:13px;--ui-section-space:44px}}
.vi-phrase{white-space:nowrap;display:inline-block}
.vi-function-icon{display:block;width:20px;height:20px;flex:none;fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}
.vi-original-symbol{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip-path:inset(50%)!important;white-space:nowrap!important;border:0!important}
.site-header nav a{font-size:14px;font-weight:500}
.site-header .header-cta{font-weight:500;border-radius:4px}
.author-marketing{padding-top:var(--ui-section-space);padding-bottom:var(--ui-section-space);gap:clamp(40px,5vw,88px)}
.author-marketing h2{font-size:var(--ui-title);line-height:1.3;letter-spacing:-.025em;font-weight:600}
.author-marketing .author-degree{font-size:24px;line-height:1.45;font-weight:500;margin-top:20px}
.author-marketing .author-founder{font-size:16px;line-height:1.75;font-weight:400;margin-top:8px}
.author-marketing .author-results{margin-top:32px;padding:24px 0;gap:20px}
.author-marketing .author-results dd{font-size:var(--ui-number);font-weight:600;line-height:1.12;letter-spacing:-.025em}
.author-marketing .author-results dt{font-size:14px;line-height:1.7;color:var(--ui-muted);min-height:1.7em}
.author-marketing .author-results small{font-size:16px;font-weight:500;margin-left:4px}
.author-marketing .author-results .result-plus{font-size:.5em;top:0;vertical-align:super;line-height:0}
.author-marketing .author-proof{gap:12px 24px;margin:24px 0;align-items:baseline}
.author-marketing .author-proof li{font-size:14px;line-height:1.7;gap:6px;white-space:nowrap}
.author-marketing .author-proof strong{font-size:14px;font-weight:500}
.author-marketing .author-intro{font-size:var(--ui-body);font-weight:400;line-height:1.8;margin-top:0;max-width:36em}
.author-marketing .credentials{margin:24px 0 12px}
.author-marketing .credentials>div,
.author-marketing .credentials>div:first-child{grid-template-columns:72px minmax(0,1fr);gap:20px;padding:20px 0;font-size:16px;line-height:1.8}
.author-marketing .credentials dt{font-size:14px;font-weight:500;line-height:1.8;padding-top:2px;white-space:nowrap}
.author-marketing .credentials dd{font-size:inherit;line-height:1.8}
.author-marketing .author-career{gap:12px}
.author-marketing .author-career strong{font-weight:500;color:var(--ui-ink)}
.author-marketing .credentials dd strong{font-weight:500;color:var(--ui-ink)}
.author-marketing .quiet-link,.books-editorial .collection-explore{font-size:14px;font-weight:500;gap:12px;min-height:44px}
.quiet-link .vi-arrow{width:20px;height:20px}
.books-editorial{padding-top:var(--ui-section-space);padding-bottom:var(--ui-section-space)}
.books-editorial .books-heading{margin-bottom:36px}
.books-editorial #books-title,
.books-editorial #books-tsinghua .exam-series-heading h2{font-size:var(--ui-title);line-height:1.35;letter-spacing:-.025em;font-weight:600}
.books-editorial .books-heading>p,
.books-editorial #books-tsinghua .exam-series-heading>p{font-size:14px;line-height:1.75;margin-bottom:16px}
.books-editorial .publisher-emphasis{font-weight:500}
.books-editorial .collection-summary{border-top-width:4px;padding:32px 0 36px;column-gap:clamp(32px,5vw,80px)}
.books-editorial .collection-title h3{font-size:var(--ui-group);line-height:1.4;font-weight:600}
.books-editorial .collection-title>span{font-size:14px;font-weight:500;color:var(--ui-muted)}
.books-editorial .collection-counts{margin-top:24px;gap:24px}
.books-editorial .collection-counts dd{font-size:var(--ui-number);line-height:1.15;font-weight:600;letter-spacing:-.025em;font-variant-numeric:lining-nums tabular-nums}
.books-editorial .collection-counts dt{font-size:14px;line-height:1.7;font-weight:400}
.books-editorial .collection-method h4{font-size:24px;font-weight:500;line-height:1.5;margin:0 0 24px}
.books-editorial .collection-method .type-branch{margin:24px 0}
.books-editorial .collection-method .type-branch .branch-root{font-size:16px;font-weight:400}
.books-editorial .collection-method .type-branch .branch-name{font-size:20px;font-weight:500}
.books-editorial .collection-method .method-guide{font-size:16px;font-weight:400;line-height:1.8}
.books-editorial .collection-method .method-guide .method-phrase:first-child{font-weight:500}
.books-editorial .collection-method .method-motto{font-size:14px;font-weight:400;line-height:1.75;margin-top:8px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{padding-top:32px;row-gap:32px}
.books-editorial .book-list .book-cover{margin-bottom:16px}
.books-editorial .book-list h3{font-size:17px;font-weight:500;line-height:1.65;letter-spacing:0}
.books-editorial .book-list p{font-size:14px;font-weight:400;line-height:1.75;margin-top:8px}
.books-editorial .collection-junior .book-list p{font-weight:500;color:var(--ui-ink)}
.books-editorial .junior-books-group{margin-top:72px}
.books-editorial #books-tsinghua{margin-top:72px;padding-top:32px}
.books-editorial #books-tsinghua .exam-series-heading{margin-bottom:32px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:26px;font-weight:500;line-height:1.5;margin-bottom:12px}
.books-editorial #books-tsinghua .exam-book-copy p{font-size:15px;line-height:1.8}
footer.social-footer{padding-top:48px;padding-bottom:20px}
footer.social-footer .footer-brand-row{padding-bottom:28px}
footer.social-footer .footer-brand p{font-size:13px;line-height:1.8}
footer.social-footer .footer-social-main{padding:36px 0;gap:32px}
footer.social-footer .footer-social-main h2{font-size:30px;line-height:1.4;font-weight:600}
footer.social-footer .social-account figcaption{font-size:13px;font-weight:500}
footer.social-footer .footer-top{font-size:12px;gap:10px;min-height:44px}
footer.social-footer .footer-registration,
footer.social-footer .footer-registration a{font-size:11px;line-height:1.7;font-weight:400}
footer.social-footer .footer-registration{padding-top:16px;gap:4px 24px}
footer.social-footer .footer-registration a{min-height:36px}
.contact-dialog{border-radius:4px;padding:24px}
.contact-dialog-heading h2{font-size:26px;line-height:1.4;font-weight:600}
.contact-dialog-close{width:44px;height:44px;border-radius:4px;display:grid;place-items:center}
@media(min-width:761px) and (max-width:1050px){.author-marketing{grid-template-columns:minmax(0,4fr) minmax(0,6fr);gap:32px}
.author-marketing .author-results{gap:12px}
.author-marketing .author-results dd{font-size:44px}
.author-marketing .credentials>div,.author-marketing .credentials>div:first-child{grid-template-columns:64px minmax(0,1fr);gap:12px}
.books-editorial .collection-method h4{font-size:24px}}
@media(max-width:760px){.site-header nav a{font-size:13px}
.author-marketing{gap:32px;padding-top:44px;padding-bottom:44px}
.author-marketing .author-degree{font-size:20px;margin-top:16px}
.author-marketing .author-founder{font-size:15px;margin-top:8px}
.author-marketing .author-results{gap:12px;margin-top:24px;padding:20px 0}
.author-marketing .author-results dt{font-size:13px;line-height:1.7;min-height:3.4em}
.author-marketing .author-results small{font-size:14px}
.author-marketing .author-proof{gap:12px 20px;margin:20px 0}
.author-marketing .author-proof li{font-size:13px;gap:6px}
.author-marketing .author-proof strong{font-size:14px;font-weight:500}
.author-marketing .credentials{margin-top:24px}
.author-marketing .credentials>div,.author-marketing .credentials>div:first-child{grid-template-columns:minmax(0,1fr);gap:12px;padding:24px 0;font-size:15px}
.author-marketing .credentials dt{font-size:13px;padding-top:0}
.author-marketing .author-career{gap:12px}
.books-editorial .books-heading{margin-bottom:28px}
.books-editorial .books-heading>p,.books-editorial #books-tsinghua .exam-series-heading>p{font-size:13px;line-height:1.75;margin-bottom:16px}
.books-editorial .collection-summary{padding:24px 0 28px;row-gap:28px}
.books-editorial .collection-title>span{font-size:13px}
.books-editorial .collection-counts{margin-top:20px;gap:16px}
.books-editorial .collection-method h4{font-size:20px;line-height:1.5;margin-bottom:24px}
.books-editorial .collection-method .type-branch{margin:24px 0}
.books-editorial .collection-method .type-branch .branch-root{font-size:14px}
.books-editorial .collection-method .method-motto{font-size:13px}
.books-editorial .book-list,.books-editorial .collection-junior .book-list{padding-top:24px;gap:28px 16px}
.books-editorial .book-list .book-cover{margin-bottom:12px}
.books-editorial .book-list h3{font-size:15px;line-height:1.65}
.books-editorial .book-list p{font-size:13px}
.books-editorial .junior-books-group{margin-top:48px}
.books-editorial #books-tsinghua{margin-top:48px;padding-top:28px}
.books-editorial #books-tsinghua .exam-series-heading{margin-bottom:28px}
.books-editorial #books-tsinghua .exam-book-copy h3{font-size:20px}
.books-editorial #books-tsinghua .exam-book-copy p{font-size:14px}
footer.social-footer{padding-top:36px;padding-bottom:16px}
footer.social-footer .footer-brand p{font-size:12px}
footer.social-footer .footer-social-main{padding:28px 0;gap:24px}
footer.social-footer .footer-social-main h2{font-size:26px}
footer.social-footer .footer-registration,
 footer.social-footer .footer-registration a{font-size:10.5px}
.contact-dialog{padding:20px}
.contact-dialog-heading h2{font-size:22px}}
@media(max-width:360px){.author-marketing .credentials>div,.author-marketing .credentials>div:first-child{grid-template-columns:1fr;gap:12px}
.author-marketing .credentials dt{font-size:13px;padding-top:0}
.books-editorial .book-list h3{font-size:15px}}
#home.hero-particle .particle-actions .pill{gap:12px}
#home.hero-particle .particle-actions .pill svg{width:20px;height:20px}
#home.hero-particle .particle-actions{align-items:center}
#home.hero-particle .particle-action-note{line-height:1.75}
.author-marketing .author-results dd{display:flex;align-items:baseline}
.author-marketing .author-results .result-plus{align-self:flex-start;position:relative;top:.2em;line-height:1;vertical-align:baseline}
.books-editorial .collection-method>p.method-description{margin-top:24px;line-height:1.8}
.books-editorial #books-tsinghua{border-top-width:4px}
.books-editorial .book-list h3{overflow-wrap:normal}
.books-editorial .publisher-emphasis{vertical-align:baseline}
@media(max-width:760px){.author-marketing .author-proof li{align-items:baseline}
.books-editorial .collection-method>p.method-description{margin-top:24px}
.books-editorial .book-list h3{line-height:1.6}
.books-editorial .collection-junior .book-list p{font-weight:500}
.books-editorial #books-title .vi-phrase,
 .books-editorial #tsinghua-books-title .vi-phrase{max-width:100%}}
#home.hero-particle{--hero-copy-size:19px}
#home.hero-particle .particle-description,
#home.hero-particle .particle-kicker,
#home.hero-particle .particle-description .particle-motto{font-size:var(--hero-copy-size)}
#home.hero-particle .particle-kicker{font-weight:500}
.books-editorial .collection-summary{display:block;padding:32px 0;border-top:4px solid var(--collection-accent);border-bottom:1px solid #BDBDBD}
.books-editorial .collection-overview{display:grid;grid-template-columns:minmax(200px,1fr) minmax(0,1.6fr);align-items:center;gap:40px;padding-bottom:28px;border-bottom:1px solid #D5D5D5}
.books-editorial .collection-title{display:flex;align-items:baseline;gap:16px}
.books-editorial .collection-counts{max-width:none;margin:0;gap:32px;grid-template-columns:repeat(3,minmax(0,1fr))}
.books-editorial .collection-counts>div{display:flex;flex-direction:column;align-items:flex-start;gap:6px}
.books-editorial .collection-counts dd{font-size:clamp(40px,3.3vw,48px);line-height:1.15}
.books-editorial .collection-counts dt{font-size:14px;line-height:1.7;white-space:nowrap}
.books-editorial .collection-method{display:grid;grid-template-columns:minmax(0,.95fr) minmax(0,1.2fr) minmax(0,1fr);align-items:center;gap:32px;padding-top:28px}
.books-editorial .collection-method h4{max-width:none;margin:0;font-size:24px;line-height:1.65;font-weight:500;text-wrap:balance}
.books-editorial .collection-method .type-branch{width:100%;max-width:440px;margin:0;justify-self:center}
.books-editorial .collection-method .type-branch.branch-two .branch-tiers{width:100%}
.books-editorial .collection-method .type-branch .branch-root{font-size:14px;line-height:1.7}
.books-editorial .collection-method .type-branch .branch-name{font-size:20px;font-weight:500;line-height:1.5}
.books-editorial .collection-method>p.method-description{max-width:none;margin:0;line-height:1.8}
.books-editorial .collection-method .method-guide{font-size:16px;line-height:1.8;text-wrap:pretty}
.books-editorial .collection-method .method-motto{font-size:14px;line-height:1.75;margin-top:12px;text-align:left;text-wrap:pretty}
footer.social-footer .footer-social-main{padding:0 0 36px;align-items:start}
footer.social-footer .social-account{gap:12px}
footer.social-footer .social-account figcaption{min-height:24px;font-size:14px;line-height:1.7}
footer.social-footer .footer-brand-row{padding:28px 0 20px;border-top:1px solid #BDBDBD;border-bottom:0;align-items:center}
footer.social-footer .footer-brand .footer-wordmark{display:inline-block;cursor:default}
footer.social-footer .footer-wordmark sup{font-size:.42em;font-weight:500;vertical-align:super;line-height:0;margin-left:3px}
footer.social-footer .footer-registration{border-top:0;padding-top:0}
@media(min-width:761px) and (max-height:800px){#home.hero-particle{--hero-copy-size:18px}}
@media(min-width:761px) and (max-width:1150px){.books-editorial .collection-overview{grid-template-columns:minmax(180px,.8fr) minmax(0,1.5fr);gap:32px}
.books-editorial .collection-method{grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:24px 32px}
.books-editorial .collection-method h4{grid-column:1/-1;font-size:22px;text-wrap:pretty}}
@media(max-width:760px){#home.hero-particle{--hero-copy-size:15px}
.books-editorial .collection-summary{padding:24px 0 28px}
.books-editorial .collection-overview{grid-template-columns:minmax(0,1fr);gap:24px;padding-bottom:24px}
.books-editorial .collection-title{gap:12px}
.books-editorial .collection-counts{margin:0;gap:20px}
.books-editorial .collection-counts dd{font-size:clamp(34px,9.2vw,40px)}
.books-editorial .collection-counts dt{font-size:13px}
.books-editorial .collection-method{grid-template-columns:minmax(0,1fr);gap:24px;padding-top:24px}
.books-editorial .collection-method h4{font-size:20px;line-height:1.6}
.books-editorial .collection-method .type-branch{max-width:340px;margin:0 auto}
.books-editorial .collection-method .type-branch .branch-name{font-size:18px}
.books-editorial .collection-method .type-branch.branch-two{max-width:280px}
.books-editorial .collection-method .method-guide{font-size:15px}
.books-editorial .collection-method .method-motto{font-size:13px;margin-top:8px}
footer.social-footer .footer-social-main{padding:0 0 28px;gap:24px}
footer.social-footer .social-account{gap:12px}
footer.social-footer .social-account figcaption{font-size:13px;min-height:24px}
footer.social-footer .footer-brand-row{padding:24px 0 20px;gap:16px}
footer.social-footer .footer-registration{padding-top:0}}
@media(max-width:760px){.learning-network .network-heading .network-heading-actions{display:none}
footer.social-footer .footer-registration{display:grid;grid-template-columns:max-content max-content;align-items:center;justify-content:start;column-gap:clamp(6px,2vw,12px);row-gap:4px;flex-direction:row;text-align:left}
footer.social-footer .footer-registration .footer-company{grid-column:1/-1}
footer.social-footer .footer-registration a{max-width:none;white-space:nowrap}}
#home.hero-particle .particle-kicker{font-size:var(--hero-copy-size);color:#d4d7dc}
@media(max-width:760px){.author-marketing .author-results{grid-template-columns:.95fr 1.2fr 1.1fr}
.author-marketing .author-results dt{font-size:var(--teacher-note-size)}
.author-marketing .author-results>div:last-child dt{white-space:nowrap}
.author-marketing .author-proof{--proof-size:clamp(10.5px,3.15vw,12px);display:flex;flex-wrap:nowrap;justify-content:space-between;align-items:baseline;gap:clamp(4px,1.5vw,8px)}
.author-marketing .author-proof li{flex:0 0 auto;gap:3px;font-size:var(--proof-size);line-height:1.75;white-space:nowrap}
.author-marketing .author-proof strong{font-size:inherit;font-weight:500}
.author-marketing .author-career>li:nth-child(-n+2){font-size:var(--teacher-career-size);line-height:1.8;white-space:nowrap}
.author-marketing .author-career>li:nth-child(-n+2) strong{font-size:inherit}
.books-editorial .collection-method>p.method-description{width:100%;text-align:center;justify-self:stretch}
.books-editorial .collection-method .method-guide,
 .books-editorial .collection-method .method-motto{text-align:center}}
.network-selection-snapshot{position:absolute;inset:0;z-index:1;overflow:hidden;pointer-events:none;background:#f0f0f0}
.network-selection-snapshot>canvas{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}
@media(prefers-reduced-motion:no-preference){.vi-reveal-pending{opacity:0;transform:translateY(20px)}
.learning-network.node-detail-mode .network-reading-pane,.learning-network.node-detail-mode .network-local-map{animation:none}
.learning-network .module-items button{transition:opacity 220ms ease,color 180ms ease,border-color 180ms ease,background-color 180ms ease}
.quiet-link .vi-arrow,.footer-top .vi-arrow,.network-return .vi-arrow{transition:transform 170ms ease}
.header-cta,.quiet-link,.footer-top,.network-return,.network-zoom button,.network-stages button,.contact-dialog-close{transition:transform 150ms ease,background-color 150ms ease,color 150ms ease}
.header-cta.vi-is-pressed,.quiet-link.vi-is-pressed,.footer-top.vi-is-pressed,.network-return.vi-is-pressed,.network-zoom button.vi-is-pressed,.network-stages button.vi-is-pressed,.contact-dialog-close.vi-is-pressed{transform:scale(.98)}
body .books-editorial .book-list .book-cover img,body .books-editorial #books-tsinghua .exam-book-cover img{transition:transform 180ms ease}
body .books-editorial .book-list .book-cover.vi-is-pressed img,body .books-editorial #books-tsinghua .exam-book-cover.vi-is-pressed img{transform:scale(.99)}}
@media(hover:hover) and (pointer:fine) and (prefers-reduced-motion:no-preference){body .books-editorial .book-list .book-cover:hover img,body .books-editorial #books-tsinghua .exam-book-cover:hover img{transform:translateY(-4px)}
.quiet-link:hover .vi-arrow{transform:translateX(3px)}
.footer-top:hover .vi-arrow{transform:translateY(-3px)}
.network-return:hover .vi-arrow{transform:translateX(-3px)}}
@media(max-width:760px){.vi-reveal-pending{transform:translateY(12px)}}
@media(prefers-reduced-motion:reduce){.vi-reveal-pending{opacity:1;transform:none}
.learning-network.node-detail-mode .network-reading-pane,.learning-network.node-detail-mode .network-local-map{animation:none!important}
.network-selection-snapshot{display:none}}
@media(prefers-reduced-motion:no-preference){#home .particle-actions .pill .vi-arrow{transition:transform 180ms cubic-bezier(.2,.65,.3,1)}
#home .particle-actions .pill:focus-visible .vi-arrow{transform:translateY(4px)}
#home .particle-actions .pill:active .vi-arrow,#home .particle-actions .pill.hero-arrow-pressed .vi-arrow{transform:translateY(4px);transition-duration:110ms}}
@media(hover:hover) and (pointer:fine) and (prefers-reduced-motion:no-preference){#home .particle-actions .pill:hover .vi-arrow{transform:translateY(4px)}}
@media(prefers-reduced-motion:reduce){#home .particle-actions .pill .vi-arrow{transform:none;transition:none}}
#author .author-proof{--proof-inline-gap:6px;display:flex;flex-wrap:nowrap;align-items:baseline;justify-content:flex-start;gap:12px 24px}
#author .author-proof li{display:flex;flex:0 0 auto;align-items:baseline;gap:var(--proof-inline-gap);font-size:16px;line-height:1.75;white-space:nowrap}
#author .author-proof strong,#author .author-proof span{font-size:inherit;line-height:inherit}
#author .author-proof.proof-stacked{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));align-items:start}
#author .author-proof.proof-stacked li{flex-direction:column;align-items:flex-start;gap:2px}
#author .author-intro{font-size:var(--teacher-note-size)}
@media(max-width:760px){#author .author-copy{width:100%;max-width:100%;min-width:0;align-self:stretch}
#author .author-proof{gap:12px;justify-content:space-between}
#author .author-proof li{font-size:var(--teacher-career-size)}
#author .author-intro{font-size:var(--teacher-note-size)}}
@media(max-width:760px){#author .author-career>li:nth-child(3){font-size:var(--teacher-career-size)}
#author .author-career>li:nth-child(3) strong{font-size:inherit}}