:root{--yellow:#fff08a;--cream:#fffef3;--line:#e9e9df;--ink:#232820;--muted:#7b8274;--link:#407b84;--gold:#e2be35;--sans:"Segoe UI","Microsoft YaHei",sans-serif;--serif:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif}
*{box-sizing:border-box}body{margin:0;color:var(--ink);background:#fff;font:16px/1.8 var(--sans)}a{color:var(--link);text-decoration:none}a:hover{text-decoration:underline}button,input,select{font:inherit}button{cursor:pointer;color:inherit;background:none;border:0}button,a,input,select{outline-offset:4px}::selection{background:#fff0a0}.skip{position:fixed;top:-100px;background:white;padding:12px;z-index:99}.skip:focus{top:0}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.topbar{height:76px;background:var(--yellow);display:flex;align-items:center;padding:0 34px;gap:40px;border-bottom:1px solid #e9d977;position:sticky;top:0;z-index:20}.brand{font-size:25px;font-weight:700;letter-spacing:2px;color:#20291a;white-space:nowrap}.brand:hover{text-decoration:none}.header-home{font-size:16px;color:#303729;white-space:nowrap}.header-help{font-size:13px;color:#5d684f;white-space:nowrap;border-bottom:1px solid #c9bd7c;line-height:1.5}.header-help:hover{color:#303729;border-color:#756a3e}.search{margin-left:auto;display:flex;width:310px;background:#fffde9;border:1px solid #e5db9c;padding:5px 12px;align-items:center}.search input{width:100%;min-width:0;background:transparent;border:0;outline:none;font-size:14px}.search:focus-within{outline:2px solid #8f8144;outline-offset:2px}.search button{font-size:26px;line-height:1.2;padding:0 3px}.account{font-size:14px;white-space:nowrap;padding:4px 0}.layout{display:grid;grid-template-columns:255px minmax(0,1fr);max-width:1600px;margin:auto;min-height:calc(100vh - 76px)}
.subject-sidebar{background:var(--cream);border-right:1px solid var(--line);padding:40px 28px}.subject-sidebar h2,.reader-sidebar h2{display:table;font-size:22px;font-weight:500;margin:0 0 26px;padding-bottom:5px;border-bottom:3px solid var(--gold)}.sidebar-tree,.sidebar-tree-children{list-style:none;margin:0;padding:0}.sidebar-tree-children{margin:2px 0 7px 11px;padding-left:14px;border-left:1px solid var(--line)}.side-link{display:flex;align-items:center;gap:13px;padding:10px 8px;font-size:14px;margin:4px 0;color:#555e48}.selected{background:#f4efd2}.side-no{font:15px Georgia;color:#a5a992}.subject-sidebar a:hover{background:#f5f2dc;text-decoration:none}
main{padding:44px 62px 60px;min-width:0}h1{font-size:32px;line-height:1.5;font-weight:500;margin:0 0 32px}h2{font-weight:500}main:focus{outline:none}.subject-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:35px 58px}.subject-section{padding:0 0 25px;border-bottom:1px solid var(--line)}.subject-section h2{display:flex;gap:16px;align-items:baseline;margin:0 0 15px;font-size:21px}.subject-section h2>a{color:var(--ink)}.section-no{font:22px Georgia;position:relative;min-width:16px}.section-no:after{content:"";position:absolute;left:0;right:0;bottom:-7px;height:3px;background:var(--gold)}.course-list{list-style:none;margin:0;padding:0 0 0 32px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px 18px;font-size:15px}.course-list a{display:inline-block;padding:2px 0}.crumb{display:flex;flex-wrap:wrap;gap:10px;font-size:13px;color:#9a9e93;margin:0 0 30px}.crumb a{color:#77836a}.crumb>span:last-child{color:#707766}.large-course-list{list-style:none;padding:0;margin:0;max-width:760px}.large-course-list li{padding:14px 0;border-bottom:1px solid var(--line);font-size:19px}.page-heading{display:flex;justify-content:space-between;align-items:center;gap:25px;margin-bottom:34px}.page-heading h1{margin:0}.outline-button{font-size:13px;border:1px solid #d9decc;padding:6px 13px;background:#fff;border-radius:2px;white-space:nowrap}.outline-button:hover{background:#fffbe5}.directory-heading{font-size:24px;margin:0 0 23px;font-weight:400}.material-list{list-style:none;padding:0;margin:0}.material-list li{margin:14px 0;font-size:19px}
.reader-layout{display:grid;grid-template-columns:285px minmax(0,1fr);max-width:1600px;margin:auto;min-height:calc(100vh - 76px)}.reader-sidebar{background:var(--cream);border-right:1px solid var(--line);padding:32px 28px;position:sticky;top:76px;height:calc(100vh - 76px);overflow:auto}.back-course{font-size:16px;display:block;margin-bottom:25px;color:#687a57}.reader-sidebar select{width:100%;padding:7px 10px;border:1px solid #dddccb;background:#fffef8;font-size:14px;color:#68745b;margin-bottom:30px}.reader-sidebar h2{margin-bottom:15px}.toc-link{display:flex;gap:13px;font-size:16px;line-height:1.8;padding:12px 9px;color:#a68a35;margin:5px 0}.toc-link>span{color:#b4b6a1;font-weight:600}.toc-link.active{background:#f6efc7;color:#645518}.toc-link:hover{text-decoration:none;background:#f9f3d7}.reading-main{padding:28px 54px 40px}.reading-main .crumb{margin-bottom:18px}.reader-toolbar{display:flex;justify-content:space-between;align-items:center;gap:15px;border-bottom:1px solid var(--line)}.page-tabs{display:flex;gap:28px}.page-tabs a{font-size:13px;color:#828c75;padding:9px 0;border-bottom:2px solid transparent}.page-tabs a.active{color:#3e4b33;border-color:var(--gold)}.reading-paper{min-height:500px;padding:33px 0 25px}.reading-paper h1{display:flex;gap:22px;align-items:flex-start;font-size:31px}.chapter-no{position:relative;font-family:Georgia}.chapter-no:after{content:"";position:absolute;left:-4px;right:-4px;bottom:-8px;height:4px;background:#e6c335}.reading-pagination{display:flex;justify-content:space-between;gap:20px;border-top:1px solid var(--line);padding-top:20px;font-size:14px}.empty-state{color:#939a88;font-size:14px}.search-results{list-style:none;padding:0;margin:0}.search-results li{border-bottom:1px solid var(--line);padding:17px 0;display:flex;justify-content:space-between;gap:20px}.search-results a{font-size:18px}.search-results span{font-size:13px;color:#939b87}
dialog{width:min(420px,calc(100vw - 36px));border:1px solid #dddccb;border-radius:5px;padding:30px;box-shadow:0 20px 80px #22332222;color:var(--ink)}dialog::backdrop{background:#22281e55}.close{position:absolute;right:13px;top:6px;font-size:25px;color:#909982}dialog h2{font-size:23px;margin:0 0 16px}dialog p{font-size:14px;color:#7f8872;margin:0}
@media(max-width:1100px){.topbar{padding:0 25px;gap:28px}.brand{font-size:22px}.search{width:255px}.layout{grid-template-columns:225px minmax(0,1fr)}.subject-sidebar{padding:34px 22px}main{padding:36px 36px}.subject-grid{gap:28px}.subject-section h2{font-size:19px}.course-list{font-size:14px;gap:7px 13px}.reader-layout{grid-template-columns:240px minmax(0,1fr)}.reading-main{padding:26px 34px}}
@media(max-width:850px){.header-home{display:none}.subject-grid{grid-template-columns:1fr}.course-list{grid-template-columns:repeat(2,minmax(0,1fr))}.subject-section h2{font-size:21px}.course-list{font-size:16px}.reader-sidebar{padding:28px 20px}}
@media(max-width:620px){.topbar{height:auto;min-height:108px;position:relative;padding:13px 18px;gap:13px;flex-wrap:wrap}.brand{font-size:22px;letter-spacing:1px}.account{margin-left:auto;font-size:12px}.header-help{order:2;font-size:12px}.search{order:3;width:100%;padding:5px 10px}.search input{font-size:13px}.layout{display:block}.subject-sidebar{padding:12px 18px;border-right:0;border-bottom:1px solid var(--line)}.subject-sidebar h2{display:none}.subject-sidebar nav{display:block;max-height:45vh;overflow:auto;scrollbar-width:thin}.sidebar-tree-children{margin-left:10px;padding-left:12px}.side-link{white-space:normal;padding:7px 10px;margin:0;font-size:12px}.side-no{font-size:12px}main{padding:28px 23px 40px}h1{font-size:28px;margin-bottom:30px}.subject-grid{gap:27px}.subject-section{padding-bottom:23px}.subject-section h2{font-size:20px;gap:13px}.section-no{font-size:21px}.course-list{padding-left:29px;font-size:15px;gap:9px 16px}.crumb{font-size:12px;gap:7px;margin-bottom:25px}.page-heading{margin-bottom:28px}.outline-button{font-size:11px;padding:5px 9px}.material-list li{font-size:18px}.directory-heading{font-size:22px}.reader-layout{display:block}.reader-sidebar{position:relative;top:0;height:auto;padding:18px 22px;border-bottom:1px solid var(--line)}.back-course{display:inline-block;margin:0 0 18px;font-size:17px}.reader-sidebar select{width:120px;float:right;font-size:12px;margin:0}.reader-sidebar h2{clear:both;font-size:20px;margin-bottom:6px}.reader-sidebar nav{display:flex;overflow:auto;gap:9px;scrollbar-width:thin}.toc-link{flex-shrink:0;font-size:14px;padding:9px 11px;gap:10px}.reading-main{padding:24px 23px 40px}.page-tabs{gap:22px}.page-tabs a{font-size:12px}.reading-paper{min-height:390px;padding-top:29px}.reading-paper h1{font-size:26px;gap:20px}.reading-pagination{font-size:12px}.search-results li{align-items:center}.search-results a{font-size:17px}.search-results span{font-size:10px}}

.actions,.form-actions,.editor-tools{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.form-actions{margin-top:20px}.primary{background:#f7e475;border:1px solid #d3bd49;padding:7px 16px;border-radius:2px}button:disabled{opacity:.6;cursor:wait}.status-text,small{font-size:12px;color:#737b68}.status-text{margin-left:12px}label{display:block;font-size:14px}label input,label select,label textarea{display:block;width:100%;margin:5px 0 14px;padding:8px 10px;border:1px solid #d4d8c9;border-radius:2px;background:#fff;min-width:0;font:inherit;color:inherit}textarea{resize:vertical}dialog #modal-message p{margin-bottom:12px;line-height:1.8}dialog label{margin-top:12px}dialog .form-error,.form-error{color:#a43c29;white-space:pre-wrap;font-size:14px}.archive-list>div{display:flex;justify-content:space-between;gap:12px;margin:12px 0}.material-section{border-bottom:1px solid var(--line);padding:12px 0 20px}.section-heading{display:flex;align-items:center;justify-content:space-between;gap:16px}.section-heading h2{font-size:22px}.editor-main{max-width:1600px;margin:auto;padding:30px 42px}.editor-fields{display:grid;grid-template-columns:minmax(0,1fr) 180px 120px;gap:20px}.editor-tools{margin:10px 0 20px}.file-label{cursor:pointer;border:1px solid #d9decc;font-size:13px;padding:6px 12px;position:relative;overflow:hidden}.file-label input{position:absolute;inset:0;opacity:0;cursor:pointer;margin:0}.editor-columns{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:24px;align-items:start}.source-pane textarea{height:60vh;min-height:360px;font:15px/1.75 Consolas,"Microsoft YaHei",monospace;tab-size:2;white-space:pre;overflow:auto}.preview-pane{min-height:calc(60vh + 26px);padding:0 22px 22px;border-left:1px solid var(--line);min-width:0}.preview-pane h2{font-size:14px;margin:0 0 18px}.tex-body{font-family:var(--serif);font-size:18px;line-height:2;overflow-wrap:anywhere}.tex-body h2{font-size:25px;margin:30px 0 16px}.tex-body h3{font-size:22px;margin:24px 0 12px}.tex-body h4{font-size:19px;margin:20px 0 10px}.tex-gap{display:block;height:1em}.tex-theorem{margin:22px 0}.qed{float:right}.tex-display{display:block;max-width:100%;overflow-x:auto;overflow-y:hidden;padding:8px 0}.tex-inline{white-space:normal}.tex-body .katex{font-size:1.12em}.tex-error,.tex-unknown{white-space:pre-wrap;overflow-wrap:anywhere;color:#a43c29;font-size:14px}.warnings{background:#fffae6;border-left:3px solid #dac45f;padding:10px 15px;font:13px/1.7 var(--sans);margin-bottom:20px;overflow-wrap:anywhere}.warnings ul{padding-left:20px}.syntax-help{margin:18px 0;font-size:13px;color:#6a745b}.syntax-help p{margin:8px 0;max-width:900px}.history-row{display:flex;align-items:center;justify-content:space-between;gap:18px;padding:14px 0;border-bottom:1px solid var(--line);font-size:14px}.history-row small,.comment small{display:block}.source-comparison{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.source-comparison textarea{min-height:320px;font:13px/1.7 Consolas,monospace}.comment{border-bottom:1px solid var(--line);padding:14px 0;margin-bottom:14px;overflow-wrap:anywhere}.comment p{white-space:normal}.comments+form textarea{min-height:140px}.reader-sidebar>a:first-child{display:block;margin-bottom:24px}.reader-sidebar button{margin-top:20px}.reading-paper>h1{overflow-wrap:anywhere}
@media(max-width:900px){.editor-main{padding:25px}.editor-columns{grid-template-columns:1fr}.preview-pane{border-left:0;border-top:1px solid var(--line);padding:20px 0;min-height:200px}.source-pane textarea{height:45vh}.reader-toolbar{flex-wrap:wrap;padding-bottom:12px}.editor-fields{grid-template-columns:minmax(0,1fr) 140px}.editor-fields>label:first-child{grid-column:1/-1}}
@media(max-width:620px){.editor-main{padding:20px}.editor-fields{gap:10px}.editor-tools{gap:7px}.source-comparison{grid-template-columns:1fr}.tex-body{font-size:17px}.page-heading{gap:12px;flex-wrap:wrap}.page-heading h1{font-size:26px}.brand{font-size:20px}.account{max-width:40%;overflow:hidden;text-overflow:ellipsis}.section-heading h2{font-size:20px}.reading-paper{padding-top:24px}.reading-main{padding:23px 18px}.reader-sidebar nav{display:block;max-height:220px;overflow:auto}.toc-link{white-space:normal}.source-pane textarea{font-size:14px}.editor-fields>label{min-width:0}}

\ndialog{max-height:85vh;overflow-y:auto}.archive-list>div>span{overflow-wrap:anywhere;min-width:0}\n.page-tree{display:block}.tree-link{display:block;padding:9px 8px 9px calc(8px + var(--depth,0)*14px);line-height:1.7;overflow-wrap:anywhere;color:#6d7958}.tree-link.active{background:#f5edc8}.page-body{margin:28px 0;min-width:0}.page-body:empty{display:none}.subpages{list-style:none;padding:15px 0;margin:20px 0}.subpages li{padding:12px 0;border-bottom:1px solid var(--line);font-size:19px}.page-maintenance{display:flex;gap:12px;flex-wrap:wrap;margin-top:38px;padding-top:16px;border-top:1px solid var(--line)}.editor-fields{grid-template-columns:minmax(0,1fr) minmax(120px,180px) 100px minmax(180px,220px)}.editor-fields>label{min-width:0}.preamble-panel{margin:0 0 18px;font-size:14px}.preamble-panel textarea{min-height:120px;font:14px/1.7 Consolas,"Microsoft YaHei",monospace}.preamble-panel small{display:block;line-height:1.8}.preview-heading{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-bottom:15px}.preview-heading h2{margin:0 auto 0 0}.preview-heading button{white-space:normal}#preview-status{font:13px/1.6 var(--sans);white-space:pre-wrap;color:#78765f}.tex-image{display:block;max-width:100%;height:auto;margin:20px auto}.tex-body figure{margin:20px 0;text-align:center}.tex-body figcaption{font-size:15px;color:#6b735e}.pdf-document{width:100%;min-width:0}.pdf-page{position:relative;margin:0 auto 16px;width:100%;max-width:1000px;background:white;box-shadow:0 0 0 1px #eee}.pdf-page canvas{display:block;width:100%;height:auto}.pdf-link{position:absolute;display:block;z-index:2;cursor:pointer}.pdf-link:hover,.pdf-link:focus{background:#ffeb5f33;outline:1px solid #bda430}.page-body>.pdf-document{max-width:950px}.archive-list button{flex-shrink:0}.preview-pane{overflow-wrap:anywhere}.pdf-document p{font-size:14px}
@media(max-width:1100px){.editor-fields{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}}
@media(max-width:620px){.editor-fields{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}.editor-fields>label:first-child{grid-column:1/-1}.page-maintenance{margin-top:24px}.reader-sidebar .page-tree{display:block;max-height:200px}.reader-sidebar{padding-bottom:18px}.page-heading{margin-bottom:18px}.reader-toolbar{gap:9px}.subpages li{font-size:18px}.preview-pane{padding-left:0;padding-right:0}}

.banana-page{width:100%;height:75vh;min-height:600px;border:0}

/* Independent discussion room; course reading styles stay unchanged. */
.forum-topics{list-style:none;padding:0}.forum-topics li{padding:16px 0;border-bottom:1px solid #ddd}.forum-topics small{display:block;color:#666;margin-top:6px}.forum-post{padding:18px 0;border-bottom:1px solid #ddd}.forum-markdown{overflow-wrap:anywhere;text-align:left;line-height:1.8}.forum-markdown pre,.forum-post pre{overflow:auto;white-space:pre-wrap;background:#f6f6f6;padding:12px}.forum-markdown blockquote{border-left:3px solid #bbb;margin-left:0;padding-left:14px;color:#555}.forum-markdown .katex-display{overflow-x:auto;overflow-y:hidden;padding:5px 0}#forum-compose textarea{width:100%;min-height:180px}#forum-preview{max-height:300px;overflow:auto;border:1px solid #ddd;padding:12px;margin-bottom:12px}
@media(max-width:600px){.topbar{flex-wrap:wrap}.forum-post .form-actions{flex-wrap:wrap}}
@media(max-width:850px){.topbar{height:auto;min-height:76px;flex-wrap:wrap;gap:14px;padding-top:12px;padding-bottom:12px}.header-discussion{display:inline-block}.search{max-width:100%}}
.page-body .theorem-proof{border:0;border-left:2px solid #00a090;padding:0 0 0 1.5rem}.recent-change>div{flex:1;min-width:0}.recent-change>button{align-self:flex-start;flex-shrink:0}.recent-change pre{white-space:pre-wrap;overflow-wrap:anywhere}@media(max-width:768px){.page-body .theorem-proof{padding-left:1.2rem}}
.page-tree-content{margin:20px 0 28px}
.page-body.empty-parent-page-body{display:none}
.reader-layout.sidebar-collapsed{grid-template-columns:minmax(0,1fr)}
.reader-layout.sidebar-collapsed>.reader-sidebar{display:none}
.about-page{max-width:860px;overflow-wrap:anywhere}.about-page section+section{margin-top:32px}.about-page h2{font-size:23px;line-height:1.5;margin:0 0 14px}.about-page p{margin:0 0 16px}.about-page code{font-family:var(--sans);font-size:1em}.about-page a{text-decoration:underline;text-underline-offset:3px}
.catalog-overview{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px;max-width:900px}
.catalog-card{display:flex;align-items:center;min-height:150px;padding:28px 32px;background:var(--cream);border:1px solid var(--line);border-top:3px solid var(--gold);color:var(--ink)}
.catalog-card:hover{background:#fffbe5;text-decoration:none;border-color:#d9d4bd}
.catalog-card h2{font-size:23px;font-weight:500;margin:0}
@media(max-width:620px){.catalog-overview{grid-template-columns:1fr;gap:16px}.catalog-card{min-height:100px;padding:20px 24px}.catalog-card h2{font-size:21px}}