.lecture-reader-shell-module__IwxGJa__shell{--reader-green:#2e7d5b;--reader-green-soft:#f2f7f4;--reader-ink:#2b2b28;--reader-muted:#6f6f68;--reader-line:#e3e1da;--reader-paper:#fdfdfc;--reader-serif:"Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "SimSun", serif;--reader-kai:"Kaiti SC", "STKaiti", "KaiTi", "楷体", "Songti SC", serif;min-height:100vh;color:var(--reader-ink);font-family:var(--font-sans);background:#f5f5f2}.lecture-reader-shell-module__IwxGJa__shell,.lecture-reader-shell-module__IwxGJa__shell *{box-sizing:border-box}body:has([data-reader-shell])>main{width:100%;max-width:none;padding:0}body:has([data-reader-shell])>footer{display:none}.lecture-reader-shell-module__IwxGJa__progress{z-index:90;background:var(--reader-green);height:2px;transition:width .12s linear;position:fixed;inset:0 auto auto 0}.lecture-reader-shell-module__IwxGJa__topbar{z-index:50;border-bottom:1px solid var(--reader-line);-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#f0efe9f2;align-items:center;gap:18px;height:58px;padding:0 22px;display:flex;position:sticky;top:0}.lecture-reader-shell-module__IwxGJa__brand{align-items:center;display:flex}.lecture-reader-shell-module__IwxGJa__mobileMenuSlot{display:none}.lecture-reader-shell-module__IwxGJa__breadcrumb{min-width:0;color:var(--reader-muted);align-items:center;gap:9px;font-size:13px;display:flex}.lecture-reader-shell-module__IwxGJa__breadcrumb a:hover{color:var(--reader-green)}.lecture-reader-shell-module__IwxGJa__breadcrumb strong{max-width:min(38vw,260px);color:var(--reader-ink);text-overflow:ellipsis;white-space:nowrap;font-weight:550;overflow:hidden}.lecture-reader-shell-module__IwxGJa__topActions{align-items:center;gap:10px;margin-left:auto;display:flex}.lecture-reader-shell-module__IwxGJa__searchButton,.lecture-reader-shell-module__IwxGJa__iconButton,.lecture-reader-shell-module__IwxGJa__panelToggle{border:1px solid var(--reader-line);color:var(--reader-muted);background:#fff;align-items:center;gap:9px;display:inline-flex}.lecture-reader-shell-module__IwxGJa__panelToggle{white-space:nowrap;padding:8px 10px;font-size:11px}.lecture-reader-shell-module__IwxGJa__panelToggle[aria-pressed=true]{background:var(--reader-green-soft);color:var(--reader-green);border-color:#bad2c3}.lecture-reader-shell-module__IwxGJa__searchButton{min-width:210px;padding:8px 10px;font-size:12px}.lecture-reader-shell-module__IwxGJa__searchButton svg,.lecture-reader-shell-module__IwxGJa__iconButton svg,.lecture-reader-shell-module__IwxGJa__mobileBar svg,.lecture-reader-shell-module__IwxGJa__commandInput svg{fill:none;stroke:currentColor;stroke-width:1.7px;width:17px}.lecture-reader-shell-module__IwxGJa__searchButton kbd{border:1px solid var(--reader-line);margin-left:auto;padding:1px 5px;font-size:10px}.lecture-reader-shell-module__IwxGJa__aiButton{background:var(--reader-green);color:#fff;padding:9px 15px;font-size:12px;font-weight:650}.lecture-reader-shell-module__IwxGJa__workspace{grid-template-columns:248px minmax(0,1fr) 224px;align-items:start;display:grid}.lecture-reader-shell-module__IwxGJa__workspace.lecture-reader-shell-module__IwxGJa__leftCollapsed{grid-template-columns:minmax(0,1fr) 224px}.lecture-reader-shell-module__IwxGJa__workspace.lecture-reader-shell-module__IwxGJa__rightCollapsed{grid-template-columns:248px minmax(0,1fr)}.lecture-reader-shell-module__IwxGJa__workspace.lecture-reader-shell-module__IwxGJa__leftCollapsed.lecture-reader-shell-module__IwxGJa__rightCollapsed{grid-template-columns:minmax(0,1fr)}.lecture-reader-shell-module__IwxGJa__leftCollapsed .lecture-reader-shell-module__IwxGJa__leftPanel,.lecture-reader-shell-module__IwxGJa__rightCollapsed .lecture-reader-shell-module__IwxGJa__rightPanel{display:none}.lecture-reader-shell-module__IwxGJa__leftPanel,.lecture-reader-shell-module__IwxGJa__rightPanel{background:#f4f3ee;height:calc(100vh - 58px);position:sticky;top:58px;overflow-y:auto}.lecture-reader-shell-module__IwxGJa__leftPanel{border-right:1px solid var(--reader-line);padding:20px 14px}.lecture-reader-shell-module__IwxGJa__rightPanel{border-left:1px solid var(--reader-line);padding:20px 16px}.lecture-reader-shell-module__IwxGJa__panelHeader{color:var(--reader-muted);letter-spacing:.12em;justify-content:space-between;align-items:center;margin-bottom:15px;font-size:11px;font-weight:700;display:flex}.lecture-reader-shell-module__IwxGJa__panelHeader button{color:var(--reader-muted);font-size:10px}.lecture-reader-shell-module__IwxGJa__panelHeader button:hover{color:var(--reader-green)}.lecture-reader-shell-module__IwxGJa__tree{padding-top:4px}.lecture-reader-shell-module__IwxGJa__tree details+details{margin-top:12px}.lecture-reader-shell-module__IwxGJa__tree summary{cursor:pointer;color:var(--reader-muted);justify-content:space-between;align-items:center;padding:6px 7px;font-size:11px;font-weight:700;list-style:none;display:flex}.lecture-reader-shell-module__IwxGJa__tree summary::-webkit-details-marker{display:none}.lecture-reader-shell-module__IwxGJa__tree ol{margin-top:3px}.lecture-reader-shell-module__IwxGJa__tree li a{text-align:left;color:#565b55;grid-template-columns:25px 1fr;gap:6px;width:100%;padding:7px;font-size:12px;line-height:1.45;display:grid}.lecture-reader-shell-module__IwxGJa__tree li a span{color:#a4a8a1;padding-top:2px;font-size:9px}.lecture-reader-shell-module__IwxGJa__tree li a:hover{color:var(--reader-ink);background:#f0f2ed}.lecture-reader-shell-module__IwxGJa__tree .lecture-reader-shell-module__IwxGJa__activeLesson a{background:var(--reader-green-soft);color:var(--reader-green);font-weight:650}.lecture-reader-shell-module__IwxGJa__tree .lecture-reader-shell-module__IwxGJa__activeLesson a span{color:var(--reader-green)}.lecture-reader-shell-module__IwxGJa__subjectGroup+.lecture-reader-shell-module__IwxGJa__subjectGroup{margin-top:6px}.lecture-reader-shell-module__IwxGJa__tree .lecture-reader-shell-module__IwxGJa__subjectSummary{color:var(--reader-ink);font-family:var(--font-serif);padding:9px 7px;font-size:13px;font-weight:650}.lecture-reader-shell-module__IwxGJa__tree .lecture-reader-shell-module__IwxGJa__subjectSummary:hover,.lecture-reader-shell-module__IwxGJa__subjectGroup[open]>.lecture-reader-shell-module__IwxGJa__subjectSummary{color:var(--reader-green)}.lecture-reader-shell-module__IwxGJa__subjectMeta{color:var(--reader-muted);font-family:var(--font-sans);align-items:center;gap:7px;font-size:10px;font-weight:400;display:inline-flex}.lecture-reader-shell-module__IwxGJa__subjectMeta .lecture-reader-shell-module__IwxGJa__arrow{font-size:11px;transition:transform .15s;display:inline-block}.lecture-reader-shell-module__IwxGJa__subjectGroup[open] .lecture-reader-shell-module__IwxGJa__subjectMeta .lecture-reader-shell-module__IwxGJa__arrow{transform:rotate(90deg)}.lecture-reader-shell-module__IwxGJa__subjectBody{border-left:1px solid var(--reader-line);margin:2px 0 12px 9px;padding-left:8px}.lecture-reader-shell-module__IwxGJa__subjectBody details+details{margin-top:8px}.lecture-reader-shell-module__IwxGJa__reader{background:var(--reader-paper);min-width:0}.lecture-reader-shell-module__IwxGJa__readerInner{width:min(100%,780px);min-height:100vh;margin:0 auto;padding:68px 54px 110px}.lecture-reader-shell-module__IwxGJa__titleBlock{border-bottom:1px solid #cfd3ca;padding-bottom:30px}.lecture-reader-shell-module__IwxGJa__titleBlock>p{color:var(--reader-green);letter-spacing:.16em;margin-bottom:16px;font-size:11px;font-weight:700}.lecture-reader-shell-module__IwxGJa__titleBlock h1{max-width:620px;font-family:var(--font-serif);letter-spacing:0;font-size:clamp(32px,4vw,48px);font-weight:500;line-height:1.25}.lecture-reader-shell-module__IwxGJa__meta{color:var(--reader-muted);flex-wrap:wrap;gap:15px;margin-top:24px;font-size:11px;display:flex}.lecture-reader-shell-module__IwxGJa__meta span+span:before{content:"·";margin-right:15px}.lecture-reader-shell-module__IwxGJa__article{overflow-wrap:anywhere;font-family:var(--reader-serif);padding-top:42px;font-size:17.5px;line-height:2}.lecture-reader-shell-module__IwxGJa__article h2,.lecture-reader-shell-module__IwxGJa__article h3{color:var(--reader-ink);scroll-margin-top:88px}.lecture-reader-shell-module__IwxGJa__article h2{align-items:baseline;gap:14px;margin:72px 0 30px;font-size:24px;font-weight:700;line-height:1.5;display:flex}.lecture-reader-shell-module__IwxGJa__article h2:after{content:"";border-top:1px solid var(--reader-line);flex:1}.lecture-reader-shell-module__IwxGJa__article h2:first-of-type{margin-top:5px}.lecture-reader-shell-module__IwxGJa__article h3{margin:48px 0 20px;font-size:19px;font-weight:700}.lecture-reader-shell-module__IwxGJa__article p{text-align:justify;margin:0 0 1.6em}.lecture-reader-shell-module__IwxGJa__article ul,.lecture-reader-shell-module__IwxGJa__article ol{margin:18px 0 25px;padding-left:1.35em}.lecture-reader-shell-module__IwxGJa__article li{margin:8px 0;padding-left:.25em}.lecture-reader-shell-module__IwxGJa__article blockquote{border-left:2px solid var(--reader-green);color:#4a4a44;font-family:var(--reader-kai);margin:2.2em 0;padding:4px 0 4px 24px;font-size:16.5px}.lecture-reader-shell-module__IwxGJa__article blockquote cite{color:var(--reader-muted);text-align:right;margin-top:10px;font-size:14.5px;font-style:normal;display:block}.lecture-reader-shell-module__IwxGJa__article strong{color:var(--reader-ink);font-weight:700}.lecture-reader-shell-module__IwxGJa__article a{color:var(--reader-green);text-underline-offset:3px;text-decoration:underline}.lecture-reader-shell-module__IwxGJa__article table{border-collapse:collapse;max-width:100%;font-family:var(--font-sans);font-size:13px;display:block;overflow-x:auto}.lecture-reader-shell-module__IwxGJa__article th,.lecture-reader-shell-module__IwxGJa__article td{border:1px solid var(--reader-line);text-align:left;min-width:130px;padding:10px}.lecture-reader-shell-module__IwxGJa__article .metaBlock{border-left:3px solid var(--reader-green);background:var(--reader-green-soft);border-radius:0 6px 6px 0;margin:14px 0;padding:18px 22px;font-size:15.5px;line-height:1.9}.lecture-reader-shell-module__IwxGJa__article .metaLabel{color:var(--reader-green);font-family:var(--font-sans);letter-spacing:.1em;margin-bottom:6px;font-size:12.5px;display:block}.lecture-reader-shell-module__IwxGJa__article .metaHead{border-left:3px solid var(--reader-green);background:var(--reader-green-soft);color:var(--reader-green);font-family:var(--font-sans);letter-spacing:.1em;border-radius:0 6px 0 0;margin:28px 0 0;padding:14px 22px 6px;font-size:12.5px}.lecture-reader-shell-module__IwxGJa__article .metaHead+ul{border-left:3px solid var(--reader-green);background:var(--reader-green-soft);border-radius:0 0 6px;margin-top:0;padding:4px 22px 16px 44px}.lecture-reader-shell-module__IwxGJa__article li.metaLi{border-left:3px solid var(--reader-green);background:var(--reader-green-soft);border-radius:0 6px 6px 0;margin:10px 0;padding:12px 18px;list-style:none}.lecture-reader-shell-module__IwxGJa__article .metaLabelInline{color:var(--reader-green);font-family:var(--font-sans);letter-spacing:.1em;margin-right:8px;font-size:12.5px}.lecture-reader-shell-module__IwxGJa__lessonPager{border-top:1px solid var(--reader-line);color:var(--reader-green);justify-content:space-between;gap:20px;margin-top:72px;padding-top:24px;font-size:12px;display:flex}.lecture-reader-shell-module__IwxGJa__outline{flex-direction:column;gap:1px;display:flex}.lecture-reader-shell-module__IwxGJa__outline button{border-left:2px solid var(--reader-line);color:var(--reader-muted);text-align:left;padding:7px 5px 7px 14px;font-size:12px;line-height:1.5;transition:color .12s,border-color .12s,background .12s;position:relative}.lecture-reader-shell-module__IwxGJa__outline button:hover{color:var(--reader-ink);border-left-color:#b9bcb2}.lecture-reader-shell-module__IwxGJa__outline .lecture-reader-shell-module__IwxGJa__subheading{color:#8a8d84;padding-left:28px;font-size:11px}.lecture-reader-shell-module__IwxGJa__outline .lecture-reader-shell-module__IwxGJa__subheading:hover{color:var(--reader-ink)}.lecture-reader-shell-module__IwxGJa__outline .lecture-reader-shell-module__IwxGJa__activeOutline{border-left:2px solid var(--reader-green);background:var(--reader-green-soft);color:var(--reader-green);font-weight:650}.lecture-reader-shell-module__IwxGJa__related{border-top:1px solid var(--reader-line);margin-top:28px;padding-top:18px}.lecture-reader-shell-module__IwxGJa__related p{color:var(--reader-muted);letter-spacing:.12em;margin-bottom:8px;font-size:10px;font-weight:700}.lecture-reader-shell-module__IwxGJa__related a{color:#555b55;padding:5px 0;font-size:11px;display:block}.lecture-reader-shell-module__IwxGJa__related a:hover{color:var(--reader-green)}.lecture-reader-shell-module__IwxGJa__mobileBar,.lecture-reader-shell-module__IwxGJa__backdrop{display:none}.lecture-reader-shell-module__IwxGJa__searchLayer{z-index:100;place-items:start center;padding-top:min(18vh,160px);display:grid;position:fixed;inset:0}.lecture-reader-shell-module__IwxGJa__searchBackdrop{-webkit-backdrop-filter:blur(3px);backdrop-filter:blur(3px);background:#1216135c;width:100%;position:absolute;inset:0}.lecture-reader-shell-module__IwxGJa__command{border:1px solid var(--reader-line);background:#fff;width:min(92vw,580px);padding:10px;position:relative;box-shadow:0 24px 70px #1f282229}.lecture-reader-shell-module__IwxGJa__commandInput{border-bottom:1px solid var(--reader-line);align-items:center;gap:10px;padding:6px 8px 14px;display:flex}.lecture-reader-shell-module__IwxGJa__commandInput input{outline:none;flex:1;min-width:0;font-size:15px}.lecture-reader-shell-module__IwxGJa__commandInput kbd{color:var(--reader-muted);font-size:10px}.lecture-reader-shell-module__IwxGJa__command>p{color:var(--reader-muted);letter-spacing:.12em;padding:14px 10px 6px;font-size:10px;font-weight:700}.lecture-reader-shell-module__IwxGJa__command>button{text-align:left;justify-content:space-between;width:100%;padding:10px;font-size:13px;display:flex}.lecture-reader-shell-module__IwxGJa__command>button:hover{background:var(--reader-green-soft);color:var(--reader-green)}.lecture-reader-shell-module__IwxGJa__command>button small{color:var(--reader-muted);font-size:10px}@media (max-width:980px){.lecture-reader-shell-module__IwxGJa__workspace{grid-template-columns:220px minmax(0,1fr)}.lecture-reader-shell-module__IwxGJa__workspace.lecture-reader-shell-module__IwxGJa__leftCollapsed,.lecture-reader-shell-module__IwxGJa__workspace.lecture-reader-shell-module__IwxGJa__rightCollapsed,.lecture-reader-shell-module__IwxGJa__workspace.lecture-reader-shell-module__IwxGJa__leftCollapsed.lecture-reader-shell-module__IwxGJa__rightCollapsed{grid-template-columns:minmax(0,1fr)}.lecture-reader-shell-module__IwxGJa__rightPanel,.lecture-reader-shell-module__IwxGJa__panelToggle{display:none}}@media (max-width:720px){.lecture-reader-shell-module__IwxGJa__topbar{gap:10px;height:54px;padding:0 14px}.lecture-reader-shell-module__IwxGJa__mobileMenuSlot{display:block}.lecture-reader-shell-module__IwxGJa__iconButton{background:0 0;border:0;padding:6px}.lecture-reader-shell-module__IwxGJa__brand{display:none}.lecture-reader-shell-module__IwxGJa__breadcrumb{font-size:12px}.lecture-reader-shell-module__IwxGJa__breadcrumb a,.lecture-reader-shell-module__IwxGJa__breadcrumb span{display:none}.lecture-reader-shell-module__IwxGJa__searchButton{border:0;min-width:0;padding:6px}.lecture-reader-shell-module__IwxGJa__searchButton span,.lecture-reader-shell-module__IwxGJa__searchButton kbd,.lecture-reader-shell-module__IwxGJa__aiButton{display:none}.lecture-reader-shell-module__IwxGJa__workspace{display:block}.lecture-reader-shell-module__IwxGJa__leftPanel,.lecture-reader-shell-module__IwxGJa__rightPanel{z-index:80;width:min(86vw,320px);height:100dvh;transition:transform .22s cubic-bezier(.2,.8,.2,1);display:block;position:fixed;top:0;bottom:0}.lecture-reader-shell-module__IwxGJa__leftPanel{left:0;transform:translate(-102%)}.lecture-reader-shell-module__IwxGJa__rightPanel{right:0;transform:translate(102%)}.lecture-reader-shell-module__IwxGJa__leftPanel.lecture-reader-shell-module__IwxGJa__drawerOpen,.lecture-reader-shell-module__IwxGJa__rightPanel.lecture-reader-shell-module__IwxGJa__drawerOpen{transform:translate(0)}.lecture-reader-shell-module__IwxGJa__panelHeader button{font-size:11px;display:block}.lecture-reader-shell-module__IwxGJa__readerInner{padding:42px 24px 100px}.lecture-reader-shell-module__IwxGJa__titleBlock{padding-bottom:24px}.lecture-reader-shell-module__IwxGJa__titleBlock h1{font-size:32px}.lecture-reader-shell-module__IwxGJa__article{padding-top:34px;font-size:16px;line-height:1.9}.lecture-reader-shell-module__IwxGJa__article h2{margin-top:48px;font-size:23px}.lecture-reader-shell-module__IwxGJa__article h3{font-size:18px}.lecture-reader-shell-module__IwxGJa__lessonPager{flex-direction:column}.lecture-reader-shell-module__IwxGJa__mobileBar{z-index:60;border:1px solid var(--reader-line);padding:7px 5px calc(7px + env(safe-area-inset-bottom));-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#fffffcf5;grid-template-columns:repeat(4,1fr);display:grid;position:fixed;bottom:12px;left:12px;right:12px;box-shadow:0 12px 34px #1a231d21}.lecture-reader-shell-module__IwxGJa__mobileBar button,.lecture-reader-shell-module__IwxGJa__mobileBar a{color:var(--reader-muted);flex-direction:column;align-items:center;gap:2px;font-size:9px;display:flex}.lecture-reader-shell-module__IwxGJa__mobileBar svg{width:19px;height:19px}.lecture-reader-shell-module__IwxGJa__aiGlyph{background:var(--reader-green);color:#fff;place-items:center;width:20px;height:20px;font-size:8px;font-weight:800;display:grid}.lecture-reader-shell-module__IwxGJa__backdrop{z-index:70;opacity:0;pointer-events:none;background:#161b1747;transition:opacity .18s;position:fixed;inset:0}.lecture-reader-shell-module__IwxGJa__backdropVisible{opacity:1;pointer-events:auto;display:block}}@media (prefers-reduced-motion:reduce){.lecture-reader-shell-module__IwxGJa__leftPanel,.lecture-reader-shell-module__IwxGJa__rightPanel{transition:none}}