:root {
  --ink:#0b1220; --muted:#647084; --accent:#244bc5; --accent-soft:#eef3ff;
  --line:#dfe4ec; --soft:#f6f7f9; --white:#fff; --header:72px;
  --serif:"Songti SC","STSong","Noto Serif SC",serif;
  --sans:Inter,"SF Pro Display","PingFang SC","Microsoft YaHei",sans-serif;
}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header) + 24px)}body{margin:0;background:var(--white);color:var(--ink);font-family:var(--sans);-webkit-font-smoothing:antialiased}body.reading-page{overflow:hidden}a{color:inherit;text-decoration:none}button,input{font:inherit}.reading-progress{position:fixed;left:0;right:0;top:0;height:2px;z-index:100;background:transparent}.reading-progress i{display:block;width:0;height:100%;background:var(--accent)}
.site-header{height:var(--header);padding:0 4vw;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;border-bottom:1px solid var(--line);background:rgba(255,255,255,.96);position:sticky;top:0;z-index:100}.brand{font-family:var(--serif);font-size:24px;font-weight:800;letter-spacing:-.03em}.desktop-nav{display:flex;height:100%;gap:34px}.desktop-nav a{display:grid;place-items:center;position:relative;font-size:14px;color:#3b4658}.desktop-nav a:after{content:"";height:2px;background:var(--accent);position:absolute;left:0;right:0;bottom:0;transform:scaleX(0);transition:.2s}.desktop-nav a:hover,.desktop-nav a.is-current{color:var(--accent)}.desktop-nav a.is-current:after{transform:scaleX(1)}.header-actions{justify-self:end;display:flex;align-items:center;gap:14px}.icon-button,.menu-trigger{width:38px;height:38px;border:0;background:transparent;cursor:pointer}.icon-button span{display:block;width:15px;height:15px;border:1.5px solid var(--ink);border-radius:50%;position:relative;margin:auto}.icon-button span:after{content:"";width:6px;height:1.5px;background:var(--ink);position:absolute;right:-5px;bottom:-3px;transform:rotate(45deg)}.menu-trigger{display:none}.menu-trigger i{display:block;width:20px;height:1px;background:var(--ink);margin:5px auto;transition:transform .2s,opacity .2s}.menu-trigger[aria-expanded="true"] i:first-child{transform:translateY(3px) rotate(45deg)}.menu-trigger[aria-expanded="true"] i:last-child{transform:translateY(-3px) rotate(-45deg)}.mobile-nav-layer{display:none}
.home-main{max-width:1440px;margin:auto;padding:0 4vw}.home-hero{min-height:600px;display:grid;grid-template-columns:minmax(0,1.2fr) minmax(380px,.8fr);gap:8vw;align-items:center;border-bottom:1px solid var(--line)}.eyebrow{color:#526078;font-size:12px;font-weight:700;letter-spacing:.14em;text-transform:uppercase}.hero-copy h1{font-family:var(--serif);font-size:clamp(48px,5vw,74px);line-height:1.18;letter-spacing:-.045em;margin:22px 0 28px;max-width:820px}.hero-deck{font-size:20px;line-height:1.85;color:var(--muted);max-width:700px;margin:0}.audience-line{display:flex;align-items:center;gap:18px;margin:22px 0 0;font-size:13px;color:#657085}.audience-line span+span:before{content:"/";margin-right:18px;color:#b1b8c3}.audience-line strong{color:var(--accent);font-weight:700;border-left:1px solid var(--line);padding-left:18px}.hero-actions{display:flex;align-items:center;gap:38px;margin-top:34px}.primary-link{display:inline-flex;gap:34px;align-items:center;padding:15px 20px;background:var(--accent);color:#fff;font-weight:650;transition:.2s}.primary-link:hover{background:#1739a1}.text-link{color:var(--accent);font-weight:650;border-bottom:1px solid var(--accent);padding:14px 0}.text-link span{margin-left:24px}.hero-map{border-left:1px solid var(--line);padding-left:48px}.hero-map h2{font-family:var(--serif);font-size:27px;margin:0 0 14px}.hero-map>a{display:grid;grid-template-columns:72px 1fr auto;align-items:center;gap:18px;min-height:104px;border-bottom:1px solid var(--line)}.hero-map>a>span{font-family:var(--serif);font-size:38px;color:var(--accent)}.hero-map strong,.hero-map small{display:block}.hero-map strong{font-size:17px}.hero-map small{color:var(--muted);margin-top:7px}.hero-map i,.task-entry i,.stage-list i{font-style:normal;color:var(--accent);opacity:.75}.hero-map>a:hover i,.task-entry>a:hover i,.stage-list>a:hover i{transform:translateX(4px)}
.course-map{padding:100px 0;border-bottom:1px solid var(--line)}.course-map>header{display:grid;grid-template-columns:180px 1fr 1fr;align-items:end;margin-bottom:44px}.course-map>header .eyebrow{grid-row:1/3}.course-map h2,.task-entry h2{font-family:var(--serif);font-size:40px;letter-spacing:-.03em;margin:0}.course-map>header>p:last-child{color:var(--muted);line-height:1.7;margin:0;justify-self:end;max-width:430px}.stage-map{display:grid;grid-template-columns:repeat(2,1fr);border-top:1px solid var(--line);border-left:1px solid var(--line)}.stage-map>section{padding:30px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}.stage-title{display:flex;align-items:center;gap:18px;margin-bottom:18px}.stage-title>span{font-family:var(--serif);font-size:34px;color:var(--accent)}.stage-title h3{margin:0;font-size:19px}.stage-title p{margin:5px 0 0;color:var(--muted);font-size:13px}.stage-list a{display:grid;grid-template-columns:36px 1fr auto;gap:10px;padding:11px 0;border-top:1px solid #edf0f4;font-size:14px}.stage-list span{color:var(--muted)}.stage-list strong{font-weight:560}.stage-list i{transition:.2s}.task-entry{padding:96px 0}.task-entry header{margin-bottom:30px}.task-entry>a{display:grid;grid-template-columns:72px 1fr auto;align-items:center;padding:28px 0;border-top:1px solid var(--line)}.task-entry>a:last-of-type{border-bottom:1px solid var(--line)}.task-entry>a>span{color:var(--muted);font-size:13px}.task-entry strong{font-family:var(--serif);font-size:25px}.task-entry p{color:var(--muted);margin:7px 0 0}.task-entry i{font-size:24px;transition:.2s}.site-footer{min-height:90px;border-top:1px solid var(--line);display:grid;grid-template-columns:1fr 2fr 1fr;align-items:center;font-size:12px;color:var(--muted)}.site-footer strong{font-family:var(--serif);font-size:16px;color:var(--ink)}.site-footer a{text-align:right;color:var(--accent)}
.reading-layout{display:grid;grid-template-columns:330px minmax(0,1fr);max-width:1320px;height:calc(100vh - var(--header));margin:auto;overflow:hidden}.course-rail{height:100%;border-right:1px solid var(--line);padding:18px 16px 44px 24px;overflow-y:auto;overscroll-behavior:contain;scrollbar-width:thin}.course-rail-inner{position:static;max-height:none;overflow:visible;padding-right:4px}.rail-group{border-bottom:1px solid var(--line)}.rail-section-title{display:grid;grid-template-columns:1fr auto;gap:10px;align-items:center;padding:17px 8px;border-bottom:1px solid var(--line);background:var(--white);position:sticky;top:-18px;z-index:3}.rail-section-title strong{font-size:14px}.rail-section-title span{font-size:12px;color:var(--muted)}.rail-links{display:block;padding:8px 0 10px}.rail-links a{display:grid;grid-template-columns:28px 1fr;gap:9px;padding:8px 10px;border-left:2px solid transparent;font-size:12px;line-height:1.45;color:#536075}.rail-links a span{color:#7b8798}.rail-links a:hover{color:var(--accent)}.rail-links a.is-active{background:var(--accent-soft);border-left-color:var(--accent);color:var(--accent);font-weight:650}.lesson-accordion{padding:6px 0 12px}.rail-lesson{border-bottom:1px solid #edf0f4}.rail-lesson summary{display:grid;grid-template-columns:28px 1fr 14px;gap:9px;align-items:start;padding:11px 9px;cursor:pointer;color:#536075;list-style:none}.rail-lesson summary::-webkit-details-marker{display:none}.rail-lesson summary>span{font-size:11px;line-height:1.55;color:#7b8798}.rail-lesson summary>strong{font-size:12px;line-height:1.5;font-weight:560}.rail-lesson summary>i{width:7px;height:7px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg);margin:3px 2px 0 0;transition:.18s}.rail-lesson[open] summary>i{transform:rotate(225deg);margin-top:7px}.rail-lesson summary:hover,.rail-lesson.is-current>summary{color:var(--accent);background:var(--accent-soft)}.rail-lesson.is-current>summary{border-left:2px solid var(--accent);padding-left:7px}.lesson-subnav{padding:4px 8px 12px 37px}.lesson-subnav a,.rail-local-toc a{display:block;padding:6px 8px;border-left:2px solid #e5e9f0;color:#6b7585;font-size:11px;line-height:1.45}.lesson-subnav a:hover,.lesson-subnav a.is-active,.rail-local-toc a:hover,.rail-local-toc a.is-active{color:var(--accent);border-left-color:var(--accent);background:#f7f9ff}.rail-local-toc{margin:4px 8px 16px 36px}.rail-local-toc>strong{display:block;margin:12px 0 6px;font-size:11px;color:#39465a}.article{height:100%;padding:38px 60px 70px;min-width:0;overflow-y:auto;overscroll-behavior:contain;scroll-behavior:smooth;scrollbar-width:thin}.breadcrumb{display:flex;gap:10px;align-items:center;color:#7a8493;font-size:12px;margin-bottom:34px}.breadcrumb a:hover{color:var(--accent)}.article-header{padding-bottom:28px;border-bottom:1px solid var(--line);margin-bottom:30px}.article-label{color:var(--accent);font-size:12px;font-weight:750;letter-spacing:.08em;margin:0 0 12px}.article-header h1{font-family:var(--serif);font-size:clamp(38px,4vw,54px);line-height:1.18;letter-spacing:-.04em;margin:0}.article-deck{font-size:17px;line-height:1.8;color:var(--muted);margin:18px 0 0;max-width:760px}.prose{font-size:16px;line-height:1.85;color:#3f4a5b}.prose h3{font-family:var(--serif);font-size:28px;line-height:1.3;color:var(--ink);letter-spacing:-.025em;margin:48px 0 13px;padding-top:4px;scroll-margin-top:24px}.prose h4{font-size:18px;color:var(--ink);margin:30px 0 8px}.prose p{margin:10px 0 18px}.prose ul,.prose ol{padding-left:1.35em;margin:10px 0 24px}.prose li{margin:7px 0;padding-left:.2em}.prose strong{color:var(--ink)}.prose a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}.prose code{font-family:"SFMono-Regular",Consolas,monospace;font-size:.88em;background:var(--soft);padding:.13em .35em;border:1px solid var(--line)}.prose pre{background:#111827;color:#e8edf5;padding:20px;overflow:auto;font-size:13px;line-height:1.7;margin:24px 0}.prose pre code{background:none;border:0;padding:0;color:inherit}.prose blockquote{border-left:3px solid var(--accent);margin:24px 0;padding:4px 0 4px 20px;color:#536075}.prose hr{border:0;border-top:1px solid var(--line);margin:36px 0}.table-wrap{overflow:auto;margin:24px 0;border:1px solid var(--line)}table{border-collapse:collapse;width:100%;min-width:620px;font-size:13px}th,td{text-align:left;vertical-align:top;padding:12px 14px;border-bottom:1px solid var(--line);border-right:1px solid var(--line)}th:last-child,td:last-child{border-right:0}tr:last-child td{border-bottom:0}th{background:var(--soft);color:var(--ink)}.page-pager{display:grid;grid-template-columns:1fr 1fr;gap:30px;border-top:1px solid var(--line);margin-top:58px;padding-top:22px}.page-pager a{display:flex;flex-direction:column;gap:7px}.page-pager a:last-child{text-align:right}.page-pager span{font-size:12px;color:var(--accent)}.page-pager strong{font-size:14px;font-weight:600}.page-pager a:hover strong{color:var(--accent)}
.search-dialog{width:min(760px,calc(100vw - 32px));border:0;padding:0;box-shadow:0 30px 90px rgba(11,18,32,.24)}.search-dialog::backdrop{background:rgba(11,18,32,.48)}.search-head{display:flex;justify-content:space-between;align-items:center;padding:20px 24px 14px}.search-head label{font-family:var(--serif);font-size:21px;font-weight:750}.search-head button{border:0;background:none;color:var(--muted);cursor:pointer}.search-dialog input{width:calc(100% - 48px);margin:0 24px 18px;padding:14px 0;border:0;border-bottom:2px solid var(--ink);outline:0;font-size:18px}.search-results{max-height:55vh;overflow:auto;border-top:1px solid var(--line)}.search-results>p{padding:18px 24px;color:var(--muted)}.search-results a{display:grid;grid-template-columns:120px 1fr;gap:16px;padding:16px 24px;border-bottom:1px solid var(--line)}.search-results a:hover{background:var(--soft)}.search-results span{font-size:12px;color:var(--accent)}.search-results strong{font-size:14px}
.mobile-lesson-switcher,.mobile-lesson-layer{display:none}
@media(max-width:1180px){.reading-layout{grid-template-columns:280px minmax(0,1fr)}.desktop-nav{gap:20px}.article{padding-left:40px;padding-right:40px}.course-map>header{grid-template-columns:140px 1fr}.course-map>header>p:last-child{display:none}}
@media(max-width:820px){:root{--header:62px}.site-header{grid-template-columns:1fr auto;padding:0 20px}.brand{font-size:20px}.desktop-nav{display:none}.menu-trigger{display:block}.mobile-nav-layer{display:block;position:fixed;inset:var(--header) 0 0;z-index:90;pointer-events:none}.mobile-nav-scrim{position:absolute;inset:0;width:100%;height:100%;padding:0;border:0;background:rgba(11,18,32,.42);opacity:0;transition:opacity .22s}.mobile-nav-panel{position:relative;z-index:1;background:var(--white);padding:22px 20px 28px;border-bottom:1px solid var(--line);box-shadow:0 24px 55px rgba(11,18,32,.16);opacity:0;transform:translateY(-14px);transition:opacity .22s,transform .22s}.mobile-nav-panel>p{margin:0 0 10px;color:var(--muted);font-size:11px;font-weight:750;letter-spacing:.12em}.mobile-nav-panel>a{display:flex;align-items:center;justify-content:space-between;min-height:52px;border-top:1px solid var(--line);font-family:var(--serif);font-size:19px;font-weight:700}.mobile-nav-panel>a:after{content:"→";color:var(--accent);font-family:var(--sans);font-size:16px}.mobile-nav-panel>a.is-current{color:var(--accent)}.mobile-nav-layer.is-open{pointer-events:auto}.mobile-nav-layer.is-open .mobile-nav-scrim{opacity:1}.mobile-nav-layer.is-open .mobile-nav-panel{opacity:1;transform:translateY(0)}body.mobile-nav-open{overflow:hidden}.home-main{padding:0 20px}.home-hero{min-height:auto;grid-template-columns:minmax(0,1fr);gap:48px;padding:62px 0}.hero-copy{min-width:0}.hero-copy h1{font-size:36px;overflow-wrap:anywhere}.hero-deck{overflow-wrap:anywhere}.hero-deck{font-size:17px}.audience-line{flex-wrap:wrap;gap:8px 14px}.audience-line span+span:before{margin-right:14px}.audience-line strong{width:100%;border-left:0;padding-left:0;margin-top:4px}.hero-actions{align-items:flex-start;flex-direction:column;gap:8px}.primary-link{gap:18px}.hero-map{border-left:0;border-top:1px solid var(--line);padding:32px 0 0}.hero-map>a{grid-template-columns:52px 1fr auto;min-height:88px}.course-map{padding:66px 0}.course-map>header{display:block}.course-map>header .eyebrow{margin-bottom:12px}.course-map h2,.task-entry h2{font-size:32px}.stage-map{grid-template-columns:1fr}.stage-map>section{padding:24px 18px}.task-entry{padding:64px 0}.task-entry>a{grid-template-columns:44px 1fr auto}.task-entry strong{font-size:21px}.task-entry p{font-size:14px;line-height:1.6}.site-footer{grid-template-columns:1fr auto;gap:12px;padding:28px 0}.site-footer span{display:none}body.reading-page{overflow:auto}.reading-layout{display:block;height:auto;overflow:visible}.course-rail{display:none}.article{height:auto;padding:26px 20px 54px;overflow:visible}.breadcrumb{margin-bottom:24px;overflow:auto;white-space:nowrap}.article-header h1{font-size:38px}.article-deck{font-size:16px}.prose{font-size:16px}.prose h3{font-size:25px;margin-top:38px;scroll-margin-top:calc(var(--header) + 18px)}.page-pager{gap:18px}.page-pager strong{font-size:12px}.search-results a{grid-template-columns:90px 1fr}}
@media(max-width:820px){.course-rail-inner{max-height:none;overflow:visible;padding-right:0}}
@media(max-width:820px){html{scroll-padding-top:calc(var(--header) + 72px)}body.lesson-nav-open{overflow:hidden}.mobile-lesson-switcher{display:block;position:sticky;top:var(--header);z-index:80;background:rgba(255,255,255,.98);border-bottom:1px solid var(--line)}.mobile-lesson-trigger{display:grid;grid-template-columns:auto minmax(0,1fr) 14px;align-items:center;gap:10px;width:100%;min-height:54px;padding:8px 20px;border:0;background:transparent;text-align:left;color:var(--ink);cursor:pointer}.mobile-lesson-trigger>span{color:var(--accent);font-size:11px;font-weight:750;white-space:nowrap}.mobile-lesson-trigger>strong{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-family:var(--serif);font-size:15px}.mobile-lesson-trigger>i{width:8px;height:8px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg) translateY(-2px);transition:.2s}.mobile-lesson-trigger[aria-expanded="true"]>i{transform:rotate(225deg) translate(-2px,-2px)}.mobile-lesson-layer{display:block;position:fixed;inset:0;z-index:120;pointer-events:none}.mobile-lesson-scrim{position:absolute;inset:0;width:100%;height:100%;padding:0;border:0;background:rgba(11,18,32,.52);opacity:0;transition:opacity .22s}.mobile-lesson-sheet{position:absolute;left:0;right:0;bottom:0;max-height:min(82vh,720px);max-height:min(82dvh,720px);display:flex;flex-direction:column;background:var(--white);border-radius:20px 20px 0 0;box-shadow:0 -22px 60px rgba(11,18,32,.24);transform:translateY(104%);transition:transform .26s ease}.mobile-lesson-sheet:before{content:"";width:42px;height:4px;margin:9px auto 0;border-radius:9px;background:#d6dbe4}.mobile-lesson-sheet>header{display:flex;align-items:end;justify-content:space-between;padding:12px 20px 14px;border-bottom:1px solid var(--line)}.mobile-lesson-sheet>header p{margin:0 0 2px;color:var(--accent);font-size:10px;font-weight:800;letter-spacing:.1em}.mobile-lesson-sheet>header h2{margin:0;font-family:var(--serif);font-size:23px}.mobile-lesson-close{min-width:44px;min-height:44px;border:0;background:transparent;color:var(--muted);font-size:13px;cursor:pointer}.mobile-lesson-list{padding:4px 16px calc(24px + env(safe-area-inset-bottom));overflow-y:auto;overscroll-behavior:contain}.mobile-lesson-stage{padding:16px 0 2px}.mobile-lesson-stage>h3{display:grid;grid-template-columns:28px 1fr auto;gap:8px;align-items:baseline;margin:0 4px 8px}.mobile-lesson-stage>h3 span{font-family:var(--serif);font-size:18px;color:var(--accent)}.mobile-lesson-stage>h3 strong{font-size:13px}.mobile-lesson-stage>h3 small{color:var(--muted);font-size:10px;font-weight:500}.mobile-lesson-stage nav{border-top:1px solid var(--line)}.mobile-lesson-stage a{display:grid;grid-template-columns:30px minmax(0,1fr) auto;gap:9px;align-items:center;min-height:48px;padding:8px 10px;border-bottom:1px solid #edf0f4;color:#465267}.mobile-lesson-stage a>span{color:#7b8798;font-size:11px}.mobile-lesson-stage a>strong{font-size:13px;line-height:1.4;font-weight:580}.mobile-lesson-stage a>i{color:var(--accent);font-style:normal}.mobile-lesson-stage a>em{padding:3px 7px;border-radius:20px;background:var(--accent);color:#fff;font-size:9px;font-style:normal}.mobile-lesson-stage a.is-current{background:var(--accent-soft);color:var(--accent)}.mobile-lesson-layer.is-open{pointer-events:auto}.mobile-lesson-layer.is-open .mobile-lesson-scrim{opacity:1}.mobile-lesson-layer.is-open .mobile-lesson-sheet{transform:translateY(0)}.prose h3{scroll-margin-top:calc(var(--header) + 72px)}}
@media print{body.reading-page{overflow:visible}.site-header,.course-rail,.breadcrumb,.page-pager,.reading-progress{display:none!important}.reading-layout{display:block;height:auto;overflow:visible}.article{height:auto;overflow:visible;padding:0;max-width:none}.article-header h1{font-size:34px}.prose{font-size:11pt}.table-wrap{overflow:visible}table{min-width:0}}
@media print{.mobile-lesson-switcher,.mobile-lesson-layer{display:none!important}}