@charset "UTF-8";
:root{--ink:#142740;--muted:#607086;--blue:#235cca;--teal:#087d72;--mint:#dbf5ef;--paper:#f4f7fb;--line:#dce4ef;--white:#fff;--shadow:0 10px 36px #14274009;--radius:16px;font-family:"Segoe UI","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--paper);font-size:16px;line-height:1.7}*{box-sizing:border-box}body{margin:0}button,input,textarea,select{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}a{color:var(--blue);text-underline-offset:4px}button{cursor:pointer}button:disabled{cursor:default;opacity:.55}:focus-visible{outline:3px solid #e1a52c;outline-offset:4px}button,a{touch-action:manipulation}.skip{position:fixed;top:-60px;left:20px;background:white;padding:10px;z-index:99}.skip:focus{top:10px}.sidebar{width:238px;position:fixed;inset:0 auto 0 0;background:var(--ink);color:white;padding:36px 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Consolas,monospace;color:#8291a5;padding-top:3px}.lesson-nav a.active .number{color:var(--teal)}.lesson-nav strong{font-size:14px;display:block;font-weight:600}.lesson-nav small{font-size:12px;color:var(--muted);display:block;margin-top:3px}.reader{background:white;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden}.reader-head{padding:32px 36px 25px;background:linear-gradient(110deg,#edf7f8,#f8fbff);border-bottom:1px solid var(--line)}.reader-head h2{font-size:27px;margin:9px 0 12px}.reader-head p:last-child{margin:0;color:var(--muted);font-size:15px}.lesson-body{padding:32px 36px}.lesson-body p,.lesson-body li{font-size:16px;line-height:1.9}.lesson-body h3{margin:32px 0 12px}.lesson-body h3:first-child{margin-top:0}.lesson-body ul,.lesson-body ol{padding-left:24px}.callout{border-left:3px solid var(--teal);background:#f0faf7;padding:16px 20px;margin:25px 0;font-size:15px}.callout 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auto;gap:16px;align-items:start;padding:24px 0;border-bottom:1px solid var(--line)}.resource:first-child{padding-top:0}.resource .resource-mark{background:#e6f0fc;color:var(--blue);height:43px;width:43px;display:grid;place-items:center;border-radius:9px;font:16px Consolas}.resource h3{margin:0 0 7px}.resource p{font-size:14px;color:var(--muted);margin-bottom:8px}.resource a{font-size:14px}.map-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.map-card{background:white;border:1px solid var(--line);border-radius:14px;padding:24px}.map-card h3{margin-top:14px}.map-card p{font-size:14px;color:var(--muted)}.map-card ul{padding-left:19px;font-size:14px}.map-card .stage{font:13px Consolas;color:var(--teal)}.notebook-grid{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:24px}.saved-note{padding:18px 0;border-bottom:1px solid var(--line)}.saved-note h3{font-size:16px;margin:0 0 8px}.saved-note pre{white-space:pre-wrap;font:14px/1.7 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.lesson-nav{display:none}.muted{color:var(--muted)}.source-note{font-size:13px;color:var(--muted);margin:20px 0}.route-count{font:12px Consolas;color:var(--muted)}
@media(min-width:1600px){main{padding-top:48px}.reader-head,.lesson-body{padding-left:48px;padding-right:48px}.reader-head h2{font-size:30px}}
@media(max-width:1100px){.sidebar{width:205px;padding-left:17px;padding-right:17px}.workspace{margin-left:205px}main{padding:28px}.topbar{padding:20px 28px}.learning-layout{grid-template-columns:185px minmax(0,1fr);gap:17px}.reader-head,.lesson-body{padding:25px}.reader-head h2{font-size:24px}.map-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.notebook-grid{grid-template-columns:1fr}.lesson-nav a{padding:11px 7px}.grid{gap:15px}h1{font-size:28px}}
@media(max-width:760px){.sidebar{transform:translateX(-100%);transition:transform .2s;width:240px}.sidebar.open{transform:translateX(0);box-shadow:10px 0 70px #14274050}.workspace{margin-left:0}.mobile-menu{display:block;border:0;background:transparent;color:var(--ink);font-size:23px;margin-right:12px}.topbar{padding:15px 18px;min-height:76px;gap:8px}.topbar>div{flex:1}.top-sub{font-size:12px}.topbar .eyebrow{font-size:10px;letter-spacing:.5px}.topbar .quiet{padding:6px 9px;font-size:12px}main{padding:25px 17px 45px}.page-heading{margin-bottom:21px;display:block}h1{font-size:27px}.page-heading .pill{margin-top:12px}.learning-layout{grid-template-columns:1fr}.lesson-nav{position:static;display:flex;overflow-x:auto;padding-bottom:8px;gap:7px}.lesson-nav a{min-width:167px;padding:10px;border-color:var(--line);background:#edf2f8}.lesson-nav small{font-size:11px}.reader-head,.lesson-body{padding:24px 21px}.reader-head h2{font-size:23px}.grid,.map-grid{grid-template-columns:1fr}.card{padding:22px}.lesson-foot{padding:20px;flex-wrap:wrap}.evidence{padding:20px}.toolbar{gap:8px}.toolbar input{flex-basis:100%}.toolbar select{min-width:0;flex:1}.resource{grid-template-columns:35px 1fr;gap:13px}.resource>a{grid-column:2}.resource .resource-mark{width:35px;height:35px}.chain{gap:4px}.chain span{min-width:85px;padding:9px}.chain i{display:none}footer{padding:20px;display:block}footer span{display:block;margin-top:5px}.brand{font-size:18px}.notebook-grid{grid-template-columns:minmax(0,1fr)}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
@media print{.sidebar,.topbar,.lesson-nav,.actions,.toolbar,.lesson-foot,footer,#toast{display:none!important}.workspace{margin:0}main{padding:0}.learning-layout,.grid{display:block}.reader,.card{border:0;box-shadow:none}.reader-head{background:white}.practice{break-inside:avoid}textarea{border:1px solid #999}.lesson-body{padding:20px 0}a{color:#111}}
@media(max-width:760px){body.menu-open .sidebar{transform:translateX(0);box-shadow:10px 0 70px #14274050}} .saved-note p{overflow-wrap:anywhere} .lesson-nav a>span{font:14px Consolas,monospace;color:#8291a5;padding-top:3px}