:root{color-scheme:light;--page:#fafafa;--surface:#fff;--ink:#252b2a;--muted:#85898b;--line:#e9eaec;--soft:#edf1f7;--blue:#6176a5;--sage:#e7efdf;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--page);color:var(--ink)}button{font:inherit}button:focus-visible,a:focus-visible{outline:3px solid #6d85b6;outline-offset:3px}.skip-link{position:absolute;top:-60px;left:18px;z-index:100;background:var(--ink);color:#fff;padding:10px 14px;border-radius:8px}.skip-link:focus{top:12px}.topbar{height:65px;position:absolute;top:0;left:0;right:0;z-index:15;display:flex;align-items:center;gap:20px;padding-left:clamp(24px,8.7vw,110px);pointer-events:none}.topbar>*{pointer-events:auto}.overview-link{font-size:12px;text-decoration:none;background:#fff;border-radius:9px;padding:9px 12px;color:#61676c;box-shadow:0 2px 12px #00000008}.overview-link span{font-size:17px;vertical-align:-1px;margin-right:5px}.topbar-label{font-size:11px;color:#a0a6aa;opacity:.75}.menu-button{display:none;border:0;background:transparent;font-size:21px;color:#4b5358;cursor:pointer}.layout{display:grid;grid-template-columns:250px minmax(0,1fr);gap:145px;padding-left:clamp(24px,8.7vw,110px);padding-right:clamp(24px,5vw,64px);max-width:1500px;min-height:100vh;margin:0 auto}.sidebar{padding:79px 0 35px;position:sticky;top:0;height:100vh;overflow:auto;scrollbar-width:none}.sidebar::-webkit-scrollbar{display:none}.cover{height:250px;background:var(--sage);border-radius:14px;overflow:hidden;display:grid;place-items:center;margin-bottom:15px}.cover img{width:100%;height:100%;object-fit:cover}.cover-placeholder{font-size:11px;color:#84917f;padding:8px 11px;border:1px dashed #c4d0bd;border-radius:6px}.course-kicker{font-size:11px;color:#969ea2;margin:9px 0}.course-title{font-size:16px;line-height:1.32;letter-spacing:-.01em;margin:0 0 8px;font-weight:700}.course-summary{color:#929aa0;font-size:11px;line-height:1.7;margin:0;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}.course-summary.open{display:block}.summary-toggle{margin:5px 0 0;background:none;border:0;padding:0;color:var(--blue);font-size:11px;cursor:pointer}.sidebar-divider{border-top:1px solid var(--line);margin:16px 0 12px}.sidebar-heading{display:flex;justify-content:space-between;align-items:center;font-size:12px;color:#959da2;margin-bottom:7px}.sidebar-heading span:last-child{font-size:11px}.unit-nav{display:flex;align-items:flex-start;gap:8px;width:100%;text-align:left;background:transparent;border:0;border-radius:8px;padding:9px 8px;margin:2px 0;color:#6f777c;cursor:pointer;font-size:12px;line-height:1.45}.unit-nav:hover{background:#f1f3f6}.unit-nav[aria-current="page"]{background:#ebf0f8;color:#506486;font-weight:650}.unit-nav-num{flex:none;font-size:11px;min-width:20px;height:20px;border-radius:5px;display:grid;place-items:center;background:#f2f4f6;color:#879096}.unit-nav[aria-current="page"] .unit-nav-num{background:#657aaa;color:#fff}.main{position:relative;min-width:0;padding:14px 0 55px}.main-inner{max-width:800px}.unit-hero,.lecture-card,.small-card{background:var(--surface);border:1px solid #eeeff0;border-radius:15px;box-shadow:0 2px 10px #00000006}.unit-hero{padding:25px 23px;margin-bottom:28px}.eyebrow{font-size:12px;color:#9ba2a7;margin-bottom:10px}.unit-heading{font-size:25px;line-height:1.4;letter-spacing:-.02em;margin:0 0 10px}.unit-description{font-size:13px;line-height:1.75;color:#8b9296;max-width:720px;margin:0}.timeline{position:relative}.timeline:before{content:"";position:absolute;left:-45px;top:-45px;bottom:-18px;border-left:2px dashed #e6e9ec}.lecture-card,.small-card{position:relative;margin:0 0 27px}.lecture-card:before,.small-card:before{content:"✎";position:absolute;left:-58px;top:19px;background:#fbfbfb;color:#8996a6;border:1px solid #e6e9ec;border-radius:50%;width:25px;height:25px;display:grid;place-items:center;font-size:12px;box-shadow:0 2px 6px #00000008}.lecture-card{padding:22px 21px 12px}.lecture-heading{font-size:16px;line-height:1.5;margin:0;font-weight:600}.lecture-brief{font-size:12px;color:#969da2;margin:6px 0 15px;line-height:1.6}.lesson-list{border-top:1px solid #f2f3f4}.lesson-item+.lesson-item{border-top:1px solid #f3f4f5}.lesson-row{width:100%;min-height:50px;border:0;background:transparent;display:flex;align-items:center;text-align:left;gap:14px;padding:9px 2px;cursor:pointer;color:#454a50}.lesson-row:hover .lesson-name{color:var(--blue)}.lesson-name{flex:1;line-height:1.5;font-size:13px}.lesson-cta{flex:none;display:inline-flex;align-items:center;justify-content:center;min-width:64px;padding:5px 10px;border-radius:9px;background:#e7ecf6;color:#566b9c;box-shadow:0 1px 3px #00000014;font-size:11px}.lesson-cta:before{content:"▶";font-size:9px;margin-right:6px}.lesson-item.expanded .lesson-cta{background:#6176a5;color:#fff}.lesson-detail{padding:10px 13px 18px 0}.lesson-detail p{font-size:12px;color:#727d81;line-height:1.8;margin:0 0 10px}.lesson-detail .lesson-lead{font-weight:550;color:#525d66}.lesson-detail figure{margin:18px 0}.lesson-detail img{display:block;max-width:100%;height:auto;border-radius:9px}.lesson-detail figcaption{font-size:11px;color:#9aa2a5;margin-top:7px}.lesson-detail .pending-note{display:inline-block;border-radius:7px;background:#f1f4f8;color:#8290a2;padding:7px 10px;margin:3px 0!important}.empty-section{color:#9da4a7;font-size:12px;line-height:1.8;margin:15px 0 5px}.small-card{padding:18px 21px}.small-card:before{content:"▤"}.small-card-kind{font-size:11px;color:#a4aaae}.small-card h3{font-size:14px;font-weight:600;margin:5px 0 0;line-height:1.5}.unit-pager{display:flex;justify-content:space-between;gap:15px;margin:22px 0}.pager-button{border:1px solid #e8ebee;background:#fff;border-radius:9px;padding:9px 13px;cursor:pointer;color:#6f7d96;font-size:12px}.pager-button:hover{border-color:#bcc8da;background:#f8faff}.pager-button:disabled{visibility:hidden}.footer{font-size:10px;color:#adb4b8;text-align:center;margin:38px 0 8px}.mobile-scrim{display:none}
@media(max-width:1050px){.layout{gap:65px;grid-template-columns:250px minmax(0,1fr);padding-left:34px;padding-right:34px}.topbar{padding-left:34px}.timeline:before{left:-31px}.lecture-card:before,.small-card:before{left:-44px}}
@media(max-width:760px){.topbar{position:sticky;height:56px;padding:0 16px;background:#fafafa;border-bottom:1px solid #e9eaec;gap:12px}.menu-button{display:block}.overview-link{box-shadow:none;padding:6px 8px}.topbar-label{display:none}.layout{display:block;padding:0;min-height:calc(100vh - 56px)}.sidebar{position:fixed;z-index:30;top:56px;left:0;bottom:0;width:min(290px,86vw);height:calc(100vh - 56px);background:var(--page);transform:translateX(-100%);transition:transform .23s;padding:18px 20px 35px;box-shadow:10px 0 30px #00000015}.sidebar.open{transform:translateX(0)}.cover{height:225px}.mobile-scrim:not([hidden]){display:block;position:fixed;inset:56px 0 0;background:#26303b55;z-index:25}.main{padding:16px 16px 45px}.main-inner{max-width:none}.unit-hero{padding:20px 18px;margin-bottom:18px}.unit-heading{font-size:21px}.timeline:before,.lecture-card:before,.small-card:before{display:none}.lecture-card{padding:18px 16px 8px;margin-bottom:14px}.small-card{padding:16px;margin-bottom:14px}.lesson-row{gap:7px}.lesson-name{font-size:12px}.lesson-cta{min-width:58px;padding:5px}.unit-pager{margin:18px 0}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.sidebar{transition:none}}

.small-card-brief{font-size:12px;line-height:1.7;color:#929aa0;margin:7px 0 0}

.lesson-detail p{white-space:pre-wrap}

.whiteboard-figure{margin:20px 0 26px!important}.whiteboard-figure a{display:block;border:1px solid #e7e9ec;border-radius:11px;overflow:hidden;background:#fff}.whiteboard-figure img{width:100%;max-width:none!important;border-radius:0!important}.whiteboard-figure figcaption{margin-top:8px!important}.transcript-reading h4{font-size:15px;margin:26px 0 13px;color:#33404b}.transcript-reading p{font-size:13px;line-height:1.9;color:#4c5964;margin:0 0 13px}.transcript-reading .transcript-answer,.transcript-reading .transcript-quiz{padding:10px 13px;background:#f3f6fa;border-left:3px solid #95a9c9;border-radius:0 7px 7px 0;color:#52657a}.source-notes{margin:18px 0;padding:12px 14px;border:1px solid #e7eaee;border-radius:8px;background:#fff}.source-notes summary{cursor:pointer;color:#6176a5;font-size:12px;font-weight:600}.source-notes p{margin:14px 0 0}.source-notes figure{margin:16px 0 0}

.lesson-map{margin:20px 0 26px}.map-intro{padding:24px 26px;border:1px solid #dde5f0;border-radius:17px;background:radial-gradient(circle at 85% 8%,#e8effb 0,#f7f9fd 45%,#fff 100%)}.map-eyebrow{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.11em;color:#7186ae}.map-root-title{margin:9px 0 17px;font-size:22px;line-height:1.35;color:#25354f}.map-intro-copy p,.map-node-reading p,.map-closing p{font-size:13px;line-height:1.85;color:#475566;margin:0 0 12px}.map-pathways{display:flex;flex-wrap:wrap;gap:9px;margin-top:18px}.map-pathways button{border:1px solid #ccd8eb;border-radius:999px;background:#fff;padding:8px 13px;color:#4c6390;font-size:12px;font-weight:600;cursor:pointer}.map-pathways button:hover{background:#e9f0fa}.map-branches{position:relative;margin:26px 0 25px;padding-left:27px}.map-branches:before{content:"";position:absolute;top:14px;bottom:14px;left:11px;width:2px;background:#c7d5ed}.map-node{position:relative;margin:0 0 23px;padding:21px;border:1px solid #e4e9f1;border-radius:16px;background:#fff;box-shadow:0 6px 22px #334a7110;scroll-margin-top:25px}.map-node:before{content:"";position:absolute;left:-23px;top:29px;width:11px;height:11px;border:3px solid #fff;border-radius:50%;background:#6681b0;box-shadow:0 0 0 2px #a7bde0}.map-node-heading{display:flex;align-items:center;gap:10px;margin-bottom:17px}.map-node-heading h5{margin:0;font-size:18px;color:#29394e}.map-node-number{display:grid;place-items:center;min-width:30px;height:30px;border-radius:9px;background:#e8eef9;color:#526d9f;font-size:11px;font-weight:800}.map-node-content{display:grid;grid-template-columns:minmax(210px,.8fr) minmax(0,1.2fr);align-items:start;gap:22px}.map-board-crop{margin:0!important;position:sticky;top:20px}.map-board-window{display:block;overflow:hidden;aspect-ratio:1036 / 1752;border:1px solid #e6e7e9;border-radius:10px;background:#fff}.map-board-window img{display:block;width:300%!important;max-width:none!important;height:auto!important;border-radius:0!important}.crop-middle img{transform:translateX(-33.333333%)}.crop-right img{transform:translateX(-66.666667%)}.map-board-crop figcaption{margin:7px 0 0!important}.map-node-reading{min-width:0}.map-board-note{margin:14px 0;padding:12px 14px;border-left:3px solid #9282d6;border-radius:0 8px 8px 0;background:#f6f3ff}.map-board-label{font-size:10px;font-weight:700;color:#7665be;letter-spacing:.08em}.map-board-note p{margin:5px 0 0;line-height:1.7;overflow-wrap:anywhere}.map-node-reading .transcript-answer,.map-node-reading .transcript-quiz{padding:10px 13px;border-radius:8px;background:#edf3fb;color:#405a79}.map-closing{padding:22px 26px;border:1px solid #dce7dd;border-radius:15px;background:#f7fbf7}.map-closing h5{margin:8px 0 15px;font-size:17px;color:#335443}.source-notes{margin-top:16px}
.map-node-lead{font-size:14px!important;line-height:1.8!important;color:#344b67!important;margin:0 0 15px!important}.map-outcomes{list-style:none;margin:0 0 18px;padding:0}.map-outcomes li{position:relative;padding:0 0 0 23px;margin:0 0 10px;color:#3f5f4d;font-size:13px;line-height:1.7}.map-outcomes li:before{content:"✓";position:absolute;left:0;color:#3d9b67;font-weight:800}
.map-board-table{width:100%;margin-top:8px;border-collapse:collapse;font-size:11px;line-height:1.55;color:#514766}.map-board-table th,.map-board-table td{border:1px solid #ddd5f0;padding:6px;vertical-align:top;text-align:left}.map-board-table th{background:#ede8fa;font-weight:700}
@media(max-width:850px){.map-node-content{grid-template-columns:1fr}.map-board-crop{position:static;max-width:440px}.map-board-window{height:290px;aspect-ratio:auto}.crop-left img{transform:translateY(-20%)}.crop-middle img{transform:translate(-33.333333%,-17%)}.crop-right img{transform:translate(-66.666667%,-16%)}.map-node{padding:17px}.map-intro,.map-closing{padding:20px}.map-root-title{font-size:19px}}
.lesson-row{text-decoration:none;color:inherit}.lesson-row:hover .lesson-name{color:#536fa3}.lesson-page-topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:62px;padding:12px max(24px,calc((100vw - 1180px)/2));border-bottom:1px solid #e9eaec;background:#fafafaf2;backdrop-filter:blur(12px);font-size:12px;color:#84909a}.lesson-back{display:inline-flex;align-items:center;min-height:34px;padding:7px 11px;border-radius:8px;background:#fff;color:#566b92;text-decoration:none;font-size:13px;font-weight:600}.lesson-back:hover{background:#edf2fa}.lesson-page-shell{max-width:1180px;margin:0 auto;padding:30px 24px 55px}.lesson-page-hero{padding:31px 36px;border:1px solid #e8eaed;border-radius:18px;background:#fff}.lesson-page-location{margin:0 0 11px;font-size:12px;color:#7383a0;line-height:1.6}.lesson-page-hero h1{margin:0;font-size:clamp(24px,2.7vw,35px);line-height:1.35;color:#26313e}.lesson-page-brief{margin:15px 0 0;font-size:14px;line-height:1.85;color:#67727e}.lesson-page-content{max-width:900px;margin:25px auto 0;padding:26px 32px;border:1px solid #e8eaed;border-radius:18px;background:#fff}.lesson-page-content.has-map{max-width:none;padding:0;border:0;background:transparent}.lesson-page-content:not(.has-map)>p{font-size:14px;line-height:1.9;color:#4c5964}.lesson-page-content .lesson-map{margin-top:0}.lesson-page-pager{display:flex;justify-content:space-between;gap:18px;margin:30px 0}.lesson-page-next{display:flex;flex-direction:column;gap:5px;min-width:0;max-width:49%;padding:16px 19px;border:1px solid #e0e5ed;border-radius:12px;background:#fff;color:#61779e;text-decoration:none;font-size:12px}.lesson-page-next:last-child{margin-left:auto}.lesson-page-next strong{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:#303d4d;font-size:13px}.lesson-page-next:hover{border-color:#aabbd7;background:#f8faff}
@media(max-width:760px){.lesson-page-topbar{padding:10px 16px}.lesson-page-topbar>span{overflow:hidden;white-space:nowrap;text-overflow:ellipsis;max-width:50%}.lesson-page-shell{padding:18px 15px 35px}.lesson-page-hero{padding:22px 19px}.lesson-page-content{padding:20px 18px}.lesson-page-pager{gap:9px}.lesson-page-next{padding:12px 11px;max-width:49%}}