:root{--nav-ink:#27394e;--nav-blue:#416592;--nav-muted:#63748b;--nav-line:#dbe5f0;--nav-paper:#f3f7fc}
.course-home{margin:0;background:#fff;color:var(--nav-ink);font-family:Cantarell,"PingFang SC","Microsoft YaHei",sans-serif;-webkit-font-smoothing:antialiased}
.course-home *{box-sizing:border-box}
.course-home a{color:inherit;text-decoration:none}
.course-home a:focus-visible,.lesson-nav a:focus-visible{outline:3px solid #416592;outline-offset:5px;border-radius:3px}
.site-header,.home-main,.site-footer{max-width:1080px;margin-inline:auto;padding-inline:40px}
.site-header{height:104px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{display:flex;align-items:center;gap:12px;font-size:21px;font-weight:700}
.brand-symbol{display:grid;place-items:center;inline-size:34px;block-size:38px;border-radius:3px 10px 10px 3px;background:var(--nav-blue);color:#fff;font-size:28px;font-family:Georgia,serif;font-style:italic}
.brand-caption{font-size:14px;font-weight:400;color:var(--nav-muted);margin-left:6px}
.header-link{font-size:14px;border-bottom:1px solid var(--nav-line);padding-block:8px}
.course-intro{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:32px;align-items:center;background:var(--nav-paper);padding:48px 52px;border-radius:8px 32px 8px 8px}
.course-category{margin:0 0 18px;color:var(--nav-blue);font-size:14px}
.course-intro h1{max-width:530px;font-family:"Noto Serif CJK SC","Songti SC",SimSun,serif;font-size:clamp(30px,3.7vw,43px);font-weight:600;line-height:1.45;letter-spacing:-.025em;margin:0 0 18px;text-wrap:balance}
.course-description{font-size:15px;line-height:1.95;color:var(--nav-muted);margin:0 0 28px}
.start-link{display:inline-flex;align-items:center;justify-content:center;min-height:46px;background:var(--nav-blue);color:#fff!important;border-radius:5px;padding:10px 22px;font-size:14px}
.start-link:hover{background:#32527d}
.course-book{width:205px;height:248px;display:flex;justify-self:center;transform:rotate(5deg);box-shadow:10px 15px 0 #dfe8f4;border-radius:2px 8px 8px 2px;overflow:hidden}
.book-spine{width:15px;background:#284568;border-right:1px solid #7291b6}
.book-cover{padding:26px 22px;background:#416592;color:#fff;flex:1;display:flex;flex-direction:column;justify-content:space-between}
.book-cover>span{font-size:12px;color:#e0e9f6}
.book-cover strong{font-family:"Noto Serif CJK SC","Songti SC",SimSun,serif;font-size:27px;font-weight:500;line-height:1.55}
.book-line{height:1px;background:#7795b9;width:40px}
.contents{padding-top:52px;scroll-margin-top:24px}
.contents-heading{display:flex;align-items:center;justify-content:space-between;gap:16px;padding-bottom:20px}
.contents h2{font-size:23px;font-weight:600;margin:0}
.contents-heading>span{font-size:13px;color:var(--nav-muted)}
.lesson-list{list-style:none;padding:0;margin:0;border-top:1px solid var(--nav-line)}
.lesson-list li{border-bottom:1px solid var(--nav-line)}
.lesson-link{display:grid;grid-template-columns:46px minmax(0,1fr) 80px;gap:20px;align-items:center;padding:28px 12px;min-height:118px}
.lesson-link:hover{background:var(--nav-paper)}
.lesson-number{font-size:24px;color:#7b91ad;font-variant-numeric:tabular-nums;align-self:start;padding-top:1px}
.lesson-text h3{font-size:18px;font-weight:600;line-height:1.55;margin:0 0 8px}
.lesson-text p{font-size:14px;color:var(--nav-muted);line-height:1.8;max-width:650px;margin:0}
.read-label{font-size:13px;color:var(--nav-blue);justify-self:end;white-space:nowrap}
.update-note{font-size:13px;color:var(--nav-muted);margin:22px 0 48px}
.library-intro h1{font-size:clamp(36px,4vw,48px);margin-bottom:18px}
.catalog-counts{display:flex;gap:18px;font-size:13px;color:var(--nav-muted)}
.project-list{list-style:none;margin:0;padding:0;border-top:1px solid var(--nav-line)}
.project-list li{border-bottom:1px solid var(--nav-line)}
.project-link{display:grid;grid-template-columns:76px minmax(0,1fr) 100px;align-items:center;gap:26px;padding:30px 12px}
.project-link:hover{background:var(--nav-paper)}
.project-icon{display:grid;place-items:center;width:70px;height:90px;background:#eaf0f8;color:var(--nav-blue);border-radius:3px 9px 9px 3px;border-left:4px solid #a2b6d4}
.project-icon svg{width:30px;height:38px}
.project-copy h3{font-size:21px;font-weight:600;line-height:1.5;margin:0 0 9px}
.project-copy p{font-size:14px;line-height:1.85;color:var(--nav-muted);margin:0 0 14px;max-width:650px}
.project-meta{display:flex;flex-wrap:wrap;gap:8px 20px;font-size:12px;color:var(--nav-muted)}
.project-open{justify-self:end;font-size:14px;color:var(--nav-blue);padding:9px 14px;border:1px solid #bdcde1;border-radius:5px;white-space:nowrap}
.project-breadcrumb{display:flex;flex-wrap:wrap;gap:10px;font-size:13px;color:var(--nav-muted);line-height:1.7;margin:0 0 22px}
.project-breadcrumb a{color:var(--nav-blue)}
.project-intro{grid-template-columns:minmax(0,1fr);padding:38px 44px}
.project-intro h1{max-width:none;font-size:clamp(28px,3.3vw,38px)}
.project-intro .course-description{margin-bottom:18px;max-width:720px}
.project-details{display:flex;flex-wrap:wrap;gap:8px 22px;color:var(--nav-muted);font-size:13px;margin:0 0 24px}
.site-footer{border-top:1px solid var(--nav-line);min-height:82px;display:flex;align-items:center;justify-content:space-between;gap:16px;color:var(--nav-muted);font-size:12px}
.skip-link{position:absolute;left:16px;top:-80px;background:#fff;padding:12px;z-index:10}
.skip-link:focus{top:12px}
.lesson-nav{box-sizing:border-box;max-width:950px;margin:24px auto 0;padding:0 24px 18px;border-bottom:1px solid #dbe5f0;display:flex;align-items:center;justify-content:space-between;gap:16px;font-family:Cantarell,"PingFang SC","Microsoft YaHei",sans-serif;font-size:14px;line-height:1.6}
.lesson-nav a{color:#416592;text-decoration:none;display:inline-block;padding:8px 0}
.lesson-nav a:hover{text-decoration:underline}
.lesson-nav div{display:flex;gap:22px}
@media(max-width:700px){.site-header,.home-main,.site-footer{padding-inline:22px}.site-header{height:82px}.brand{font-size:19px}.brand-caption{font-size:12px;margin-left:2px}.header-link{font-size:12px}.course-intro{grid-template-columns:minmax(0,1fr);padding:32px 26px;border-radius:6px 22px 6px 6px}.course-book{display:none}.course-intro h1{font-size:32px}.course-description{font-size:14px}.contents{padding-top:36px}.contents h2{font-size:21px}.lesson-link{grid-template-columns:32px minmax(0,1fr);gap:14px;padding:24px 0}.lesson-number{font-size:21px}.lesson-text h3{font-size:17px}.read-label{grid-column:2;justify-self:start}.site-footer{align-items:start;flex-direction:column;justify-content:center;gap:8px;padding-block:20px}.lesson-nav{margin-top:12px;gap:10px}.lesson-nav div{gap:16px}}
@media(max-width:700px){#write table{display:block;max-width:100%;overflow-x:auto}#write table:focus-visible{outline:2px solid #416592;outline-offset:3px}}
@media(max-width:700px){.library-intro h1{font-size:36px}.catalog-counts{font-size:12px;gap:12px}.project-link{grid-template-columns:48px minmax(0,1fr);gap:16px;padding:24px 0}.project-icon{width:46px;height:62px;align-self:start}.project-icon svg{width:24px;height:30px}.project-copy h3{font-size:19px}.project-open{grid-column:2;justify-self:start;font-size:13px}.project-meta{gap:6px 12px}.project-intro{padding:28px 24px}.project-breadcrumb{font-size:12px}.lesson-nav{font-size:12px}.lesson-nav div{gap:14px}}
@media print{.lesson-nav,.skip-link{display:none}.course-book{box-shadow:none}.start-link{border:1px solid #416592}}