.stack-app{--background:var(--card-background);--foreground:var(--card-text-color-main);--card:var(--card-background);--card-foreground:var(--card-background);--muted:var(--card-text-color-secondary);--muted-foreground:var(--card-text-color-secondary);--border:var(--card-separator-color);--primary:var(--accent-color);--primary-foreground:var(--accent-color);--accent:var(--accent-color);--accent-foreground:var(--accent-color);--viz-series-1:#ad563b;--font-size-base:16px;--red:#a23d32;--ink:var(--card-text-color-main);--paper:var(--card-background);--soft:#59645f;--clay:#a45239;--font-reading:'Noto Serif SC','Source Han Serif SC','Songti SC','SimSun',serif;--font-ui:'Microsoft YaHei','PingFang SC',sans-serif}
.stack-app *{box-sizing:border-box}.stack-app{scroll-behavior:smooth;scroll-padding-top:80px}.stack-app{background:var(--card-background);color:inherit;font-family:var(--base-font-family);line-height:1.95}.stack-app a{color:inherit;text-decoration-thickness:1px;text-underline-offset:3px}.stack-app a:hover{color:inherit}.stack-app button,
.stack-app input{font-family:var(--base-font-family);font-size:14px}.stack-app button{cursor:pointer}.stack-app button:focus-visible,
.stack-app a:focus-visible,
.stack-app input:focus-visible,
.stack-app summary:focus-visible{outline:3px solid #c7834a;outline-offset:4px}.stack-app button.btn{border:1px solid var(--card-separator-color);border-radius:var(--card-border-radius);background:transparent;color:inherit;padding:8px 15px;line-height:1.5;min-height:38px}.stack-app button.btn:hover{background:var(--card-background)}.stack-app button[aria-pressed=true]{background:var(--card-background);color:inherit;border-color:var(--card-separator-color)}.stack-app [hidden]{display:none!important}
.stack-app .bookbar{position:sticky;top:0;z-index:10;background:var(--card-background);color:inherit;font-family:var(--base-font-family);display:flex;align-items:center;justify-content:space-between;gap:16px;padding:13px 30px;border-bottom:1px solid var(--card-separator-color)}.stack-app .bookbar strong{font-weight:500;font-size:14px;letter-spacing:.06em}.stack-app .bookbar span{font-size:12px;opacity:.8}.stack-app .bookbar .btn{color:inherit;border-color:var(--card-separator-color);background:transparent;padding:6px 12px;min-height:32px}.stack-app .bookbar .btn:hover{background:var(--card-background)}.stack-app .layout{display:grid;grid-template-columns:278px minmax(0,1fr);max-width:1470px;margin:auto}.stack-app .sidebar{border-right:1px solid var(--card-separator-color);padding:34px 23px;font-family:var(--base-font-family);font-size:13px;line-height:1.7;position:sticky;top:67px;align-self:start;max-height:calc(100vh - 70px);overflow:auto}.stack-app .sidebar .index-label{font-size:11px;letter-spacing:.2em;color:inherit;margin-bottom:18px}.stack-app .sidebar details{margin-bottom:20px}.stack-app .sidebar summary{cursor:pointer;font-weight:600;color:inherit;line-height:1.6;margin:5px 0 8px}.stack-app .sidebar a{display:block;text-decoration:none;color:inherit;padding:7px 9px;border-left:1px solid var(--card-separator-color);font-size:12px}.stack-app .sidebar a.current{border-color:var(--card-separator-color);color:inherit;background:var(--card-background)}.stack-app .sidebar small{display:block;font-size:11px;color:inherit;padding:7px 0}.stack-app .sidebar .top-link{margin-bottom:20px;font-size:13px;color:inherit}.stack-app .reader{padding:54px 60px 110px;min-width:0}.stack-app .reader-inner{max-width:840px;margin:auto}.stack-app .cover{border-top:1px solid var(--card-separator-color);padding:35px 0 44px;border-bottom:1px solid var(--card-separator-color);margin-bottom:48px}.stack-app .eyebrow{font-family:var(--base-font-family);font-size:12px;letter-spacing:.18em;color:inherit;font-weight:600}.stack-app .cover h1{font-weight:500;font-size:43px;line-height:1.35;letter-spacing:.04em;margin:20px 0 12px}.stack-app .cover .subtitle{font-size:23px;color:inherit;margin:0 0 24px}.stack-app .cover .description{max-width:690px;color:inherit;font-size:16px}.stack-app .meta{display:flex;flex-wrap:wrap;gap:10px 28px;font-family:var(--base-font-family);font-size:12px;color:inherit;margin-top:27px}.stack-app .guide{margin:32px 0 40px;padding-left:20px;border-left:1px solid var(--card-separator-color)}.stack-app .guide strong{color:inherit}.stack-app .guide p{margin:8px 0;font-size:15px}.stack-app .chapter-heading{padding:26px 0 25px;border-bottom:1px solid var(--card-separator-color);margin:55px 0 30px;scroll-margin-top:84px}.stack-app .chapter-heading .chapter-no{font-family:var(--base-font-family);font-size:12px;letter-spacing:.1em;color:inherit}.stack-app .chapter-heading h2{font-size:31px;line-height:1.4;font-weight:500;margin:10px 0}.stack-app .chapter-heading p{font-family:var(--base-font-family);font-size:12px;color:inherit;margin:7px 0}.stack-app .lesson{margin:0 0 38px;scroll-margin-top:84px}.stack-app .lesson+.lesson{border-top:1px solid var(--card-separator-color);padding-top:30px}.stack-app .lesson>h3{font-family:var(--base-font-family);font-weight:600;font-size:21px;line-height:1.6;margin:0 0 18px;color:inherit}.stack-app .lesson h4,
.stack-app .lesson .subhead{font-family:var(--base-font-family);font-weight:600;font-size:17px;line-height:1.65;color:inherit;margin:24px 0 12px}.stack-app .lesson p{margin:13px 0}.stack-app .lesson strong{font-weight:600;color:inherit}.stack-app .lesson ul,
.stack-app .lesson ol{padding-left:1.65em;margin:16px 0}.stack-app .lesson li{padding-left:.15em;margin:7px 0}.stack-app .lesson li p{margin:6px 0}.stack-app .lesson hr{border:0;border-top:1px solid var(--card-separator-color);margin:28px 0}.stack-app .level{font-family:var(--base-font-family);font-size:12px;display:inline-block;vertical-align:middle;line-height:1.7;padding:1px 6px;border-radius:var(--card-border-radius);margin:0 2px;background:var(--card-background);color:inherit;white-space:nowrap}.stack-app .level.use{background:var(--card-background);color:inherit}.stack-app .level.context{background:var(--card-background);color:inherit}.stack-app .table-wrap{overflow-x:auto;margin:21px 0}.stack-app table{border-collapse:collapse;width:100%;font-size:14px;line-height:1.7;font-family:var(--base-font-family)}.stack-app th{text-align:left;font-weight:600;color:inherit;background:var(--card-background);border-top:1px solid var(--card-separator-color);border-bottom:1px solid var(--card-separator-color);padding:11px 13px}.stack-app td{padding:10px 13px;vertical-align:top;border-bottom:1px solid var(--card-separator-color)}.stack-app tbody tr:nth-child(even){background:var(--card-background)}.stack-app .diagram{margin:30px 0;padding:20px 0 17px;border-top:1px solid var(--card-separator-color);border-bottom:1px solid var(--card-separator-color);font-family:var(--base-font-family);font-size:14px;line-height:1.65;break-inside:avoid}.stack-app .diagram h3{font-size:16px!important;line-height:1.5!important;margin:0 0 16px!important;font-weight:600!important;color:inherit}.stack-app .figure-label{font-family:var(--base-font-family);font-size:11px;color:inherit;letter-spacing:.08em;margin:0 0 9px}.stack-app .viz-controls{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin-bottom:15px}.stack-app .viz-controls .form-label{display:block;flex:1 1 200px;font-size:13px}.stack-app .form-label span{float:right;font-variant-numeric:tabular-nums;color:inherit}.stack-app .form-range{display:block;width:100%;accent-color:var(--ink);height:25px;margin-top:6px}.stack-app .sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.stack-app .math-display{display:block;text-align:center;padding:15px 8px;margin:18px 0;background:var(--card-background);overflow-x:auto;break-inside:avoid}.stack-app .math-inline{display:inline-block;vertical-align:middle;max-width:100%;line-height:1.1}.stack-app .math-inline mjx-container{margin:0!important}.stack-app .math-display mjx-container{margin:0!important}.stack-app .math-display svg,
.stack-app .math-inline svg{max-width:100%;height:auto}.stack-app .math-display svg{font-size:110%}.stack-app .answer-section{margin-top:27px;background:var(--card-background);padding:20px 24px}.stack-app .answer-section summary{font-family:var(--base-font-family);font-weight:600;color:inherit;cursor:pointer}.stack-app .answer-content{padding-top:9px}.stack-app .answer-content p:first-child{margin-top:8px}.stack-app .study-prompt{border-left:1px solid var(--card-separator-color);padding-left:18px;margin-top:25px}.stack-app .endnote{margin-top:55px;padding-top:25px;border-top:1px solid var(--card-separator-color);font-family:var(--base-font-family);font-size:13px;color:inherit}.stack-app .print-toc,
.stack-app .diagram-print{display:none}.stack-app .print-toc ul{padding-left:0;list-style:none;font-family:var(--base-font-family);font-size:12px;line-height:1.7}.stack-app .print-toc li{margin:5px 0}.stack-app .print-toc a{text-decoration:none}.stack-app .print-toc .toc-chapter{font-weight:600;font-size:17px;margin-top:18px}.stack-app .progress{height:2px;background:var(--card-background);position:absolute;bottom:0;left:0;width:0;transition:width .15s}.stack-app .math-source{display:none}
.stack-app .diagram .finance-flow{display:block;width:100%;overflow:visible;color:inherit}.stack-app .diagram .finance-flow text{fill:currentColor;font-family:var(--base-font-family)}.stack-app .diagram .finance-node,
.stack-app .diagram .m-node{fill:var(--muted);fill-opacity:.55;stroke:var(--border);stroke-width:1}.stack-app .diagram .finance-highlight,
.stack-app .diagram .m-active{fill:var(--viz-series-1);fill-opacity:.12}.stack-app .diagram .finance-arrow,
.stack-app .diagram .m-line{fill:none;stroke:currentColor;stroke-width:1.5}.stack-app .diagram .diagram-print svg{color:var(--foreground)}.stack-app .diagram .diagram-print svg text{fill:currentColor;font:inherit}
@media(max-width:1100px){.stack-app .layout{grid-template-columns:240px minmax(0,1fr)}.stack-app .reader{padding:38px 34px 80px}.stack-app .sidebar{padding:25px 16px}.stack-app .cover h1{font-size:37px}}
@media(max-width:760px){.stack-app{line-height:1.95}.stack-app .layout{display:block}.stack-app .bookbar{padding:11px 16px}.stack-app .bookbar span{display:none}.stack-app .sidebar{position:static;max-height:none;display:none;border-right:0;border-bottom:1px solid var(--card-separator-color);padding:22px}.stack-app .sidebar.mobile-open{display:block}.stack-app .reader{padding:30px 20px 70px}.stack-app .cover{padding-top:25px}.stack-app .cover h1{font-size:32px}.stack-app .cover .subtitle{font-size:21px}.stack-app .chapter-heading h2{font-size:25px}.stack-app .lesson>h3{font-size:19px}.stack-app .lesson .subhead{font-size:16px}.stack-app .diagram{padding-top:16px}.stack-app .answer-section{padding:17px}.stack-app .math-display{padding:12px 4px}.stack-app .table-wrap{margin-left:-2px;margin-right:-2px}.stack-app table{min-width:400px;font-size:13px}}
@media(min-width:761px){.stack-app .menu-button{display:none}}
@media print{
 @page{size:A4;margin:18mm 17mm 18mm 17mm}.stack-app{scroll-behavior:auto}.stack-app{line-height:1.8;background:var(--card-background);color:inherit;-webkit-print-color-adjust:exact;print-color-adjust:exact}.stack-app .bookbar,
.stack-app .sidebar{display:none!important}.stack-app .layout{display:block;max-width:none}.stack-app .reader{padding:0}.stack-app .reader-inner{max-width:none}.stack-app .cover{break-after:page;margin:0;padding-top:15mm;border-top-width:4px}.stack-app .cover h1{font-size:30pt}.stack-app .cover .subtitle{font-size:19pt}.stack-app .cover .description{font-size:11pt}.stack-app .cover .meta{font-size:9pt}.stack-app .guide{margin-top:9mm}.stack-app .print-toc{display:block;break-after:page}.stack-app .print-toc h2{font-size:22pt;color:inherit}.stack-app .chapter-heading{break-before:page;break-after:avoid;padding:0 0 5mm;margin:0 0 6mm}.stack-app .chapter-heading h2{font-size:22pt}.stack-app .lesson{margin-bottom:6mm}.stack-app .lesson+.lesson{padding-top:5mm}.stack-app .lesson>h3{font-size:14pt;break-after:avoid;margin-bottom:4mm}.stack-app .lesson .subhead{font-size:11.2pt;break-after:avoid;margin:5mm 0 2mm}.stack-app .lesson p{margin:2.8mm 0;orphans:3;widows:3}.stack-app .lesson li{margin:1.5mm 0}.stack-app .lesson ul,
.stack-app .lesson ol{margin:3mm 0}.stack-app .table-wrap{overflow:visible;margin:4mm 0}.stack-app table{font-size:9pt;min-width:0!important;line-height:1.55}.stack-app thead{display:table-header-group}.stack-app tr{break-inside:avoid}.stack-app td,
.stack-app th{padding:2.2mm 2.8mm}.stack-app .diagram{padding:4mm 0;margin:5mm 0;break-inside:avoid}.stack-app .diagram h3{font-size:10.8pt!important}.stack-app .figure-label{font-size:8pt}.stack-app .diagram-interactive{display:none}.stack-app .diagram-print{display:block}.stack-app .diagram-print-state{break-inside:avoid;margin:4mm 0}.stack-app .diagram-print-state h4{font-size:9.5pt;margin:2mm 0}.stack-app .diagram-print svg{display:block;max-width:100%;height:auto!important}.stack-app .diagram svg text{font-size:12px!important}.stack-app .level{font-size:8.5pt}.stack-app .math-display{padding:3mm;margin:3.5mm 0}.stack-app .math-inline svg{font-size:95%}.stack-app .answer-section{padding:4mm;background:var(--card-background);break-inside:auto}.stack-app .answer-section summary{display:block}.stack-app .answer-content{display:block!important}.stack-app .endnote{font-size:9pt}.stack-app .study-prompt{break-inside:avoid}.stack-app a{color:inherit}.stack-app .sr-only{display:none}
}
.stack-app{--viz-series-1:#a85035;--viz-series-2:#2b6d88;--viz-series-3:#416a46;--viz-series-4:#756245;--viz-series-5:#725c7d;--viz-series-6:#7a7452}
.stack-app{}.stack-app p{orphans:3;widows:3}.stack-app .bookbar .bar-actions{display:flex;gap:14px;align-items:center}.stack-app .bookbar a{color:inherit;font-size:13px;text-decoration:none}.stack-app .sidebar .top-link{font-size:13px}.stack-app .sidebar details>summary{color:inherit}.stack-app .sidebar a{line-height:1.65}.stack-app .reader-inner{max-width:840px}.stack-app .chapter-heading{margin-top:0}.stack-app .unit-meta{font-family:var(--base-font-family);letter-spacing:.05em;color:inherit;margin:0 0 6px!important}.stack-app .lesson>h3{font-family:var(--base-font-family);font-size:24px;line-height:1.5;font-weight:600}.stack-app .lesson h4{font-size:17px}.stack-app .lesson>p{max-width:100%}.stack-app .math-display{background:transparent;padding:11px 4px;margin:18px 0;overflow-x:auto;overflow-y:hidden}.stack-app .math-inline{display:inline-block;max-width:100%;vertical-align:middle}.stack-app .math-inline mjx-container{margin:0!important}.stack-app .math-display mjx-container{margin:0!important}.stack-app .math-display svg{max-width:none}.stack-app .math-inline svg{max-width:100%}.stack-app .diagram{margin:30px 0;padding:18px 0}.stack-app .diagram-interactive{display:block}.stack-app .diagram-print{display:none}.stack-app .diagram svg{color:var(--foreground)}.stack-app .diagram text{font-size:14px}.stack-app .form-select{display:block;width:100%;margin-top:7px;min-height:40px;padding:7px 10px;border:1px solid var(--card-separator-color);border-radius:var(--card-border-radius);background:var(--card-background);color:inherit;font-family:var(--base-font-family)}.stack-app .form-label{display:block;line-height:1.8}.stack-app .form-range{width:100%;display:block}.stack-app .diagram .viz-controls{align-items:start;gap:16px}.stack-app .diagram h3{font-size:17px!important}.stack-app .diagram .tabular-nums{font-variant-numeric:tabular-nums}.stack-app .answer-section{padding:14px 0;background:transparent;border:0;border-top:1px solid var(--card-separator-color);border-bottom:1px solid var(--card-separator-color);margin:24px 0}.stack-app .answer-section summary{color:inherit;font-family:var(--base-font-family);cursor:pointer}.stack-app .answer-content{padding:9px 0 0}.stack-app .answer-section:not([open])>.answer-content{display:none}.stack-app .answer-section[open]>.answer-content{display:block}.stack-app .exercise{margin-top:36px}.stack-app .section-links{display:flex;gap:18px;flex-wrap:wrap;font-family:var(--base-font-family);margin:22px 0 40px}.stack-app .section-review{margin:35px 0;padding:18px 0;border-top:1px solid var(--card-separator-color);font-size:15px}.stack-app .reading-guide{margin:28px 0 44px}.stack-app .reading-guide h2{font-weight:500;color:inherit;font-size:25px}.stack-app .print-toc{display:block;margin:28px 0 55px}.stack-app .print-toc p{display:flex;justify-content:space-between;gap:24px;border-bottom:1px solid var(--card-separator-color);padding:9px 0;margin:0}.stack-app .print-toc span{font-family:var(--base-font-family);color:inherit}.stack-app .endnote h3{font-size:17px;font-weight:500}.stack-app .index-main{max-width:1080px;margin:auto;padding:48px 40px 90px}.stack-app .index-main .cover{max-width:880px}.stack-app .index-actions{display:flex;flex-wrap:wrap;gap:16px 28px;font-family:var(--base-font-family);padding:0 0 20px}.stack-app .primary-link{font-weight:600}.stack-app .index-chapter{margin-top:48px}.stack-app .index-chapter h2{font-weight:500;font-size:26px;color:inherit}.stack-app .section-row{display:grid;grid-template-columns:62px minmax(0,1fr) auto;gap:22px;align-items:center;text-decoration:none;padding:25px 0;border-top:1px solid var(--card-separator-color)}.stack-app .section-row .number{font-family:var(--base-font-family);color:inherit}.stack-app .section-row strong{display:block;font-family:var(--base-font-family)}.stack-app .section-row small{display:block;font-family:var(--base-font-family);color:inherit;margin-top:5px}.stack-app .read-label{font-family:var(--base-font-family)}.stack-app .offline-note{font-family:var(--base-font-family);color:inherit;margin-top:30px}.stack-app h2,
.stack-app h3,
.stack-app h4{break-after:avoid}.stack-app .endnote{margin-top:45px;padding-top:22px;border-top:1px solid var(--card-separator-color)}
@media(max-width:760px){.stack-app .sidebar.is-open{display:block}.stack-app .bookbar{padding:10px 16px;gap:8px}.stack-app .bookbar strong{font-size:12px}.stack-app .bookbar .bar-actions{gap:8px}.stack-app .bookbar .btn{padding:5px 8px;font-size:12px}.stack-app .bookbar a{font-size:12px}.stack-app .reader{padding:32px 20px 70px}.stack-app .cover h1{font-size:34px}.stack-app .cover .subtitle{font-size:22px}.stack-app .chapter-heading h2{font-size:28px}.stack-app .lesson>h3{font-size:22px}.stack-app .index-main{padding:30px 20px 60px}.stack-app .section-row{grid-template-columns:45px minmax(0,1fr);gap:12px}.stack-app .read-label{display:none}.stack-app .diagram h3{font-size:16px!important}.stack-app .print-toc p{display:block}.stack-app .print-toc span{display:block;margin-top:5px}.stack-app .math-display{margin-left:-4px;margin-right:-4px}.stack-app .table-wrap{max-width:100%}.stack-app .section-links{gap:12px}.stack-app .bookbar strong{max-width:52%}}
@media(max-width:760px){.stack-app .bookbar{flex-wrap:wrap}.stack-app .bookbar strong{flex:1 1 100%;max-width:none;line-height:1.5}.stack-app .bookbar .bar-actions{width:100%;justify-content:flex-end}.stack-app .bookbar a,
.stack-app .bookbar .btn{white-space:nowrap}}
@media print{
  @page{size:A4;margin:18mm 17mm 18mm 17mm}
  .stack-app .unit-meta{break-after:avoid}.stack-app #s2-09,
.stack-app #s3-08{line-height:1.6}.stack-app #s2-09 p{margin:1.2mm 0}.stack-app #s3-08 p{margin:1.8mm 0}.stack-app #s2-09 .math-display{margin:1.2mm 0;padding:.2mm 0}.stack-app #s3-08 .math-display{margin:2mm 0;padding:.7mm 0}.stack-app #s2-09 h4,
.stack-app #s3-08 h4{margin:3mm 0 1.5mm}.stack-app #s3-08 li{margin:1mm 0}
  .stack-app{scroll-behavior:auto}.stack-app{background:var(--card-background);color:inherit;line-height:1.72}.stack-app .bookbar,
.stack-app .sidebar,
.stack-app .section-links,
.stack-app .section-review{display:none!important}.stack-app .layout{display:block;max-width:none}.stack-app .reader{padding:0}.stack-app .reader-inner{max-width:none}.stack-app .cover{padding:12mm 0 9mm;margin-bottom:7mm;border-top:1px solid var(--card-separator-color)}.stack-app .cover h1{font-size:29pt}.stack-app .cover .subtitle{font-size:19pt}.stack-app .cover .description{font-size:11pt}.stack-app .cover .meta{font-size:9pt}.stack-app .reading-guide{margin:6mm 0}.stack-app .reading-guide h2{font-size:16pt}.stack-app .print-toc{display:block!important;break-after:page;margin:8mm 0}.stack-app .print-toc h2{font-size:17pt}.stack-app .print-toc p{padding:2.5mm 0}.stack-app .print-toc span{font-size:9pt}.stack-app .chapter-heading{break-before:page;padding:0 0 4mm;margin:0 0 6mm;break-after:avoid}.stack-app .chapter-heading h2{font-size:20pt}.stack-app .chapter-heading p{font-size:9pt}.stack-app .lesson{margin:0 0 6mm;break-inside:auto}.stack-app .lesson+.lesson{padding-top:4mm}.stack-app .lesson>h3{font-size:14pt;margin:0 0 3mm}.stack-app .unit-meta{font-size:8pt;margin-bottom:1mm!important}.stack-app .lesson h4,
.stack-app .subhead{font-size:11pt;margin:4mm 0 2mm}.stack-app .lesson p{margin:2.5mm 0;orphans:3;widows:3}.stack-app .lesson li{margin:1.4mm 0}.stack-app .math-display{padding:1.5mm 0;margin:3mm 0;overflow:visible;break-inside:avoid}.stack-app .math-display svg{max-width:100%;height:auto!important}.stack-app .math-inline{display:inline-block;max-width:100%;vertical-align:middle}.stack-app .math-inline svg{max-width:100%}.stack-app .table-wrap{overflow:visible;margin:4mm 0}.stack-app table{font-size:8.7pt;line-height:1.55;min-width:0!important}.stack-app th,
.stack-app td{padding:2mm 2.4mm}.stack-app tr{break-inside:avoid}.stack-app thead{display:table-header-group}.stack-app .diagram{padding:3mm 0;margin:4mm 0;break-inside:avoid}.stack-app .diagram-interactive{display:none!important}.stack-app .diagram-print{display:block!important}.stack-app .diagram-print svg{display:block;max-width:100%;height:auto!important}.stack-app .diagram-print .print-pair{display:grid;grid-template-columns:1fr 1fr;gap:6mm}.stack-app .diagram-print text{font-size:14px!important}.stack-app .figure-label{font-size:8pt}.stack-app .answer-section{display:block;break-inside:auto;padding:3mm 0;margin:4mm 0;background:transparent}.stack-app .answer-section summary{display:block;font-size:10pt;break-after:avoid}.stack-app .answer-section>.answer-content{display:block!important;padding-top:1mm}.stack-app .answer-content p{font-size:10.3pt}.stack-app .endnote{font-size:8.7pt;line-height:1.65;margin-top:7mm}.stack-app .endnote h3{font-size:11pt}.stack-app a{color:inherit;text-decoration:none}.stack-app .exercise{margin-top:6mm}.stack-app .sr-only{display:none}
}
@media print{.stack-app .chapter-heading{break-before:auto;margin-top:7mm}.stack-app .print-toc+.chapter-heading{margin-top:0}}

.stack-app .svg-stage{max-width:100%;overflow-x:auto;background:#fffef9}.stack-app .svg-stage>svg{display:block;width:100%;height:auto;min-width:590px}.stack-app .figure-controls{display:flex;gap:15px;align-items:center;flex-wrap:wrap;margin:0 0 16px;font-family:var(--base-font-family)}.stack-app .figure-controls label{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.stack-app .figure-controls select{padding:7px 12px;min-height:39px;border:1px solid var(--card-separator-color);border-radius:var(--card-border-radius);background:var(--card-background);color:inherit;font-family:var(--base-font-family);max-width:100%}.stack-app .figure-status{font-family:var(--base-font-family);color:inherit;margin:10px 0 0}.stack-app .index-section{padding:28px 0 36px;border-top:1px solid var(--card-separator-color);margin-top:48px}.stack-app .index-section .chapter-subtitle{font-family:var(--base-font-family);color:inherit}.stack-app .index-section h2{margin-bottom:8px}.stack-app .index-section .section-row{grid-template-columns:65px minmax(0,1fr) auto;padding:17px 0}.stack-app .index-section .section-row strong{font-size:16px}.stack-app .chapter-open{display:flex;gap:22px;flex-wrap:wrap;font-family:var(--base-font-family);margin:18px 0 28px}.stack-app .source-inline{font-family:var(--base-font-family);color:inherit}.stack-app .lesson>h3{scroll-margin-top:100px}.stack-app .chapter-heading{scroll-margin-top:85px}.stack-app .exercise-tag{font-family:var(--base-font-family);color:inherit}
@media(max-width:760px){.stack-app .index-section .section-row{grid-template-columns:48px minmax(0,1fr)}.stack-app .figure-controls select{max-width:320px}.stack-app .figure-controls{display:block}.stack-app .figure-controls label{display:block}.stack-app .figure-controls select{display:block;margin-top:8px}.stack-app .diagram{margin:24px 0}.stack-app .figure-status:after{content:' 图形可在框内左右滑动查看。';display:block}.stack-app .index-section h2{font-size:24px}}
@media print{.stack-app .svg-stage>svg{min-width:0}.stack-app .figure-controls,
.stack-app .figure-status{display:none}.stack-app .diagram-print svg{width:100%;min-width:0}.stack-app .diagram-print text{font-size:14px!important}.stack-app .cover{break-after:page}.stack-app .source-inline{font-size:9pt}.stack-app .lesson{padding-bottom:1mm}.stack-app .chapter-heading{margin-top:7mm;break-inside:avoid}.stack-app .exercise-tag{font-size:8pt}.stack-app .print-toc p{break-inside:avoid}}

.stack-app main li,
.stack-app main p{overflow-wrap:anywhere}.stack-app .collection-math-display,
.stack-app .collection-math-inline{position:relative}.stack-app .collection-math-display{max-width:100%;overflow-x:auto;overflow-y:hidden;overscroll-behavior-x:contain;padding-block:.3em}.stack-app .collection-math-display>.katex-display{margin:.35em 0;text-align:inherit}.stack-app .collection-math-inline{display:inline-block;max-width:100%;vertical-align:-.15em;overflow-x:auto;overflow-y:hidden;font-family:var(--base-font-family);background:transparent!important;padding:0!important}.stack-app .collection-math-inline>.katex{font-size:1.04em}.stack-app .collection-math-svg{overflow:visible;pointer-events:none}.stack-app .collection-math-svg .katex{font-size:1em}.stack-app .eq:has(>.katex),
.stack-app .formula:has(>.katex){font-family:inherit}.stack-app .katex-display>.katex{white-space:nowrap} .stack-app .katex .katex-mathml{white-space:nowrap}