@charset "UTF-8";
.visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
:root{--ink:#142c46;--blue:#2357a6;--blue-dark:#17417f;--paper:#f5f6f2;--white:#fff;--muted:#52616f;--line:#d8e0e5;--gold:#f6ce58;--soft-blue:#edf3fa;--measure:70ch;--reading-size:19px;--radius:10px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:110px}body{margin:0;color:var(--ink);background:var(--paper);font:16px/1.65 "Segoe UI",Arial,sans-serif;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}a:hover{color:var(--blue)}button,input,select{font:inherit}button,a,input,select,summary{-webkit-tap-highlight-color:transparent}button,summary{cursor:pointer}button{color:inherit}button:disabled{cursor:default;opacity:.45}img{max-width:100%;height:auto;display:block}svg{flex-shrink:0}h1,h2,h3,p{margin-top:0}h1,h2,h3{line-height:1.16}h1,h2{font-family:Georgia,"Times New Roman",serif;font-weight:400}h1{font-size:clamp(34px,4vw,56px);letter-spacing:-1.25px}h2{font-size:clamp(29px,3vw,38px);letter-spacing:-.65px}h3{font-size:22px;font-weight:600}p{margin-bottom:1.15em}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #b57806;outline-offset:4px;border-radius:3px}::selection{background:#ffecab;color:var(--ink)}[hidden]{display:none!important}.wrap{width:min(1180px,calc(100% - 64px));margin-inline:auto}.muted{color:var(--muted)}.eyebrow{font-size:12px;font-weight:700;letter-spacing:1.6px;text-transform:uppercase}.small{font-size:14px}.mono{font-variant-numeric:tabular-nums}.text-link{color:var(--blue);text-decoration:underline;text-underline-offset:4px}.skip-link{position:fixed;left:20px;top:-100px;padding:10px 20px;background:var(--gold);z-index:100}.skip-link:focus{top:10px}.icon{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}.arrow{font-size:23px;line-height:1}.pill{display:inline-flex;align-items:center;padding:4px 10px;border-radius:5px;background:var(--soft-blue);color:var(--blue-dark);font-size:12px;font-weight:700}.button{display:inline-flex;align-items:center;justify-content:center;gap:12px;min-height:46px;padding:10px 20px;border:1px solid var(--blue);border-radius:6px;background:var(--blue);color:white;font-size:15px;font-weight:600;text-decoration:none;transition:background .15s}.button:hover{background:var(--blue-dark);color:white}.button.secondary{background:white;color:var(--blue);border-color:var(--line)}.button.secondary:hover{background:var(--soft-blue)}.button.quiet{background:transparent;color:var(--ink);border-color:var(--line)}.button.gold{background:var(--gold);color:var(--ink);border-color:var(--gold)}.button.gold:hover{background:#ffdd72}.button.ghost-light{background:transparent;color:#fff;border-color:#7391b8}.button.ghost-light:hover{background:#203e5e}.icon-button{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;min-height:44px;border:0;border-radius:6px;background:transparent}.icon-button:hover{background:var(--soft-blue)}.button-row{display:flex;flex-wrap:wrap;gap:12px}
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.page-intro{padding:42px 0 31px}.breadcrumb{font-size:13px;color:var(--muted);margin-bottom:21px}.breadcrumb ol{display:flex;gap:10px;flex-wrap:wrap;list-style:none;padding:0;margin:0}.breadcrumb li+li:before{content:"/";margin-right:10px;color:#8795a2}.page-intro h1{margin-bottom:13px}.page-intro>p{font-size:16px;max-width:65ch;color:var(--muted);margin:0}.catalog-layout{display:grid;grid-template-columns:218px minmax(0,1fr);gap:44px;padding-bottom:68px}.filter-aside{align-self:start;position:sticky;top:124px}.filter-aside h2{font:600 16px "Segoe UI",Arial,sans-serif;margin-bottom:20px}.filter-section{padding-bottom:25px;margin-bottom:24px;border-bottom:1px solid var(--line)}.filter-label{font-size:12px;font-weight:700;letter-spacing:.75px;color:var(--muted);display:block;margin-bottom:10px}.type-filters{display:flex;flex-direction:column;gap:4px}.filter-type{display:flex;align-items:center;justify-content:space-between;text-align:left;padding:9px 12px;min-height:42px;border-radius:5px;border:0;background:transparent;font-size:14px}.filter-type[aria-pressed=true]{background:#e6edf6;color:var(--blue-dark);font-weight:700}.filter-type:hover{background:var(--soft-blue)}.filter-type span{font-size:12px;color:var(--muted)}.filter-aside select{width:100%;padding:10px;min-height:44px;border:1px solid var(--line);border-radius:5px;background:white;color:var(--ink);font-size:14px}.archive-info{font-size:13px;line-height:1.7;color:var(--muted)}.catalog-toolbar{display:flex;align-items:center;gap:13px;margin-bottom:22px}.catalog-search{flex:1;display:flex;gap:9px;align-items:center;border:1px solid var(--line);border-radius:7px;background:white;min-height:48px;padding:0 14px}.catalog-search input{border:0;outline:0;min-width:0;width:100%;font-size:15px;background:transparent;color:var(--ink);height:46px}.catalog-search:focus-within{outline:3px solid #b57806;outline-offset:3px}.sort-select{font-size:13px;padding:12px 10px;border:1px solid var(--line);border-radius:6px;background:white;min-height:46px}.catalog-count{font-size:13px;color:var(--muted);margin-bottom:12px;min-height:22px}.catalog-list{background:white;border:1px solid var(--line);border-radius:9px;padding:0 26px}.material-row{padding:25px 0;display:grid;grid-template-columns:80px minmax(0,1fr);gap:23px}.material-row+.material-row{border-top:1px solid var(--line)}.row-image{width:80px;height:80px;object-fit:cover;border-radius:7px;margin-top:4px}.material-row h2{font:500 24px/1.28 "Segoe UI",Arial,sans-serif;letter-spacing:-.45px;margin-bottom:10px}.material-row p{font-size:14px;line-height:1.7;color:var(--muted);margin-bottom:10px}.material-row .card-meta{margin-bottom:8px}.row-bottom{display:flex;align-items:center;gap:12px;font-size:12px;color:var(--muted)}.review-indicator{display:inline-flex;align-items:center;gap:5px;color:#32593d;font-size:12px;font-weight:600}.review-indicator:before{content:"";width:5px;height:5px;background:#3b754a;border-radius:50%}.pagination{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-top:26px;font-size:13px;color:var(--muted)}.page-buttons{display:flex;gap:7px}.page-button{min-width:42px;height:42px;border:1px solid var(--line);background:#fff;border-radius:5px;font-size:14px}.page-button[aria-current=page]{background:var(--blue);color:white;border-color:var(--blue)}.empty-state{padding:45px 25px;text-align:center;background:white;border:1px solid var(--line);border-radius:9px}.empty-state h2{font-size:27px}.empty-state p{color:var(--muted);font-size:15px}.mobile-filter-toggle{display:none}
.reader-intro{max-width:900px;margin:0 auto;padding:40px 0 28px}.reader-intro h1{font-size:clamp(34px,4.1vw,52px);line-height:1.15;letter-spacing:-.9px;max-width:24ch;margin-bottom:25px}.reader-meta{display:flex;gap:22px;flex-wrap:wrap;font-size:14px;color:var(--muted);margin-bottom:18px}.reader-meta time{font-weight:600;color:var(--ink)}.reader-kicker{display:flex;align-items:center;gap:12px;margin-bottom:16px}.reader-kicker .eyebrow{color:var(--blue)}.archive-line{font-size:13px;color:var(--muted);padding:10px 0 10px 13px;border-left:3px solid #8494a6;max-width:76ch}.reader-layout{display:grid;grid-template-columns:minmax(0,760px) 220px;gap:48px;justify-content:center;padding-bottom:62px}.reader-sheet{min-width:0;background:white;border:1px solid var(--line);border-radius:9px;padding:35px 38px}.reader-controls{display:flex;align-items:center;justify-content:space-between;gap:18px;border-bottom:1px solid var(--line);padding-bottom:16px;margin-bottom:28px;font-size:12px;color:var(--muted)}.font-controls{display:flex;align-items:center;gap:4px}.font-controls button{height:35px;min-width:36px;background:transparent;border:1px solid transparent;border-radius:4px}.font-controls button[aria-pressed=true]{background:var(--soft-blue);border-color:#c6d5e7;color:var(--blue-dark)}.font-controls button:nth-of-type(1){font-size:13px}.font-controls button:nth-of-type(2){font-size:16px}.font-controls button:nth-of-type(3){font-size:19px}.prose{font:var(--reading-size)/1.82 Georgia,"Times New Roman",serif;overflow-wrap:break-word}.prose div{max-width:100%}.prose p{margin:0 0 1.45em}.prose h2,.prose h3{font-family:"Segoe UI",Arial,sans-serif;letter-spacing:-.35px;font-size:27px;font-weight:600;margin:1.8em 0 .8em;line-height:1.3;scroll-margin-top:120px}.prose h4{font-size:22px}.prose a{color:var(--blue);text-decoration:underline;text-underline-offset:3px;overflow-wrap:anywhere}.prose img{margin:24px auto 10px;max-width:100%;height:auto;border-radius:4px}.prose table{border-collapse:collapse;width:100%;margin:15px 0 32px;font:13px/1.65 "Segoe UI",Arial,sans-serif;color:var(--muted)}.prose td,.prose th{padding:4px 0}.prose ul,.prose ol{padding-left:25px}.prose blockquote{border-left:3px solid var(--line);margin:20px 0;padding:0 18px}.prose br+br{display:none}.prose center{margin:22px 0}.reader-side{align-self:start;position:sticky;top:124px}.reader-side h2{font:600 14px "Segoe UI",Arial,sans-serif;margin:0 0 13px}.reader-side nav{border-bottom:1px solid var(--line);padding-bottom:23px;margin-bottom:24px}.reader-side ol{list-style:none;padding:0;margin:0}.reader-side li+li{margin-top:13px}.reader-side a{font-size:13px;line-height:1.5;display:block;color:var(--muted)}.reader-side a:hover{color:var(--blue)}.reader-side .side-source{font-size:12px;text-decoration:underline;text-underline-offset:4px;color:var(--blue)}.reader-side .side-note{font-size:13px;color:var(--muted)}.mobile-toc{display:none}.editorial-note{border:1px solid #cadbed;border-left:3px solid var(--blue);border-radius:6px;background:#f1f6fc;padding:24px 25px;margin:0 0 32px;font:15px/1.75 "Segoe UI",Arial,sans-serif}.editorial-note h2{font:600 21px/1.35 "Segoe UI",Arial,sans-serif;margin:0 0 9px;letter-spacing:-.3px}.editorial-note .note-date{font-size:12px;color:var(--blue-dark);margin-bottom:16px}.editorial-note p{margin-bottom:12px}.editorial-note p:last-child{margin:0}.editorial-note details{border-top:1px solid #ccdae9;margin-top:16px}.editorial-note summary{padding:12px 0 4px;font-size:14px;font-weight:600;color:var(--blue-dark);min-height:44px}.editorial-note ul{padding-left:19px;font-size:13px;line-height:1.7}.editorial-note li+li{margin-top:9px}.editorial-note a{color:var(--blue);text-decoration:underline;text-underline-offset:3px;overflow-wrap:anywhere}.reader-end{border-top:1px solid var(--line);margin-top:36px;padding-top:24px;font-size:14px;color:var(--muted)}.reader-end h2{font:600 18px "Segoe UI",Arial,sans-serif}.reader-end a{color:var(--blue)}.reader-end .button{margin-top:8px;font-size:14px}.reader-related{padding:0 0 52px}.reader-related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.reader-related article{background:white;border:1px solid var(--line);border-radius:8px;padding:22px}.reader-related h3{font-size:19px;line-height:1.35;font-weight:500}
.tasks-layout{display:grid;grid-template-columns:236px minmax(0,1fr);gap:36px;padding-bottom:68px}.chapter-nav{background:white;border:1px solid var(--line);border-radius:8px;padding:20px 16px;position:sticky;top:125px;align-self:start}.chapter-nav h2{font:600 14px "Segoe UI",Arial,sans-serif;margin:0 9px 14px}.chapter-nav ol{list-style:none;padding:0;margin:0}.chapter-nav li+li{margin-top:5px}.chapter-nav a{display:grid;grid-template-columns:19px 1fr;gap:8px;padding:11px 9px;border-radius:5px;font-size:13px;line-height:1.5;min-height:44px}.chapter-nav a[aria-current=page]{background:var(--soft-blue);color:var(--blue-dark);font-weight:600}.chapter-nav .index{font-size:12px;color:#6d8093}.chapter-nav .all-chapters{border-top:1px solid var(--line);margin-top:14px;padding-top:15px;color:var(--blue)}.task-section-heading{display:flex;justify-content:space-between;align-items:start;gap:18px;margin-bottom:18px}.task-section-heading h2{font-size:31px;margin-bottom:8px}.task-section-heading p{font-size:14px;color:var(--muted);margin:0}.task-section-heading .pill{flex-shrink:0;font-weight:500;margin-top:3px}.task-toolbar{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:22px}.level-button{background:transparent;border:1px solid var(--line);border-radius:5px;padding:9px 13px;min-height:42px;font-size:13px}.level-button[aria-pressed=true]{background:var(--ink);color:white;border-color:var(--ink)}.task-progress{margin-left:auto;font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}.task-card{background:white;border:1px solid var(--line);border-radius:8px;margin-bottom:18px;padding:25px 28px;scroll-margin-top:118px}.task-top{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:18px}.task-top h3{font-size:19px;margin:0;font-weight:600}.task-top .pill{font-size:11px;padding:4px 9px;font-weight:600}.task-body{font:18px/1.8 Georgia,"Times New Roman",serif;margin-bottom:21px;overflow-wrap:break-word}.task-body p{margin-bottom:1em}.task-body p:last-child{margin:0}.task-body i{font-style:normal}.task-body h2{font-size:22px}.task-knowledge{font-size:13px;line-height:1.65;color:var(--muted);padding:11px 14px;background:#f4f7fa;border-radius:5px;margin-bottom:21px}.task-knowledge strong{font-weight:600;color:var(--ink)}.task-bottom{display:flex;align-items:center;justify-content:space-between;gap:14px;border-top:1px solid var(--line);padding-top:15px;font-size:12px;color:var(--muted)}.task-bottom label{display:flex;align-items:center;gap:8px;min-height:34px;cursor:pointer}.task-bottom input{accent-color:var(--blue);width:17px;height:17px}.task-bottom a{color:var(--blue);text-decoration:underline;text-underline-offset:3px}.task-card.completed{border-left:3px solid #5e8067}.task-help{font-size:13px;color:var(--muted);padding:15px 0}.task-help a{color:var(--blue);text-decoration:underline}.reset-progress{border:0;background:transparent;color:var(--blue);font-size:12px;text-decoration:underline;text-underline-offset:3px;padding:9px 0;min-height:38px}.mobile-chapters{display:none}
.site-footer{background:#fff;border-top:1px solid var(--line);padding:35px 0 26px}.footer-main{display:flex;justify-content:space-between;gap:40px;align-items:start}.footer-brand{font-size:23px;font-weight:600;color:var(--blue);margin-bottom:5px}.footer-summary{font-size:13px;color:var(--muted);max-width:42ch;margin:0}.footer-links{display:flex;gap:26px;flex-wrap:wrap;font-size:13px;color:var(--muted)}.footer-bottom{border-top:1px solid var(--line);padding-top:20px;margin-top:27px;display:flex;justify-content:space-between;gap:20px;font-size:12px;color:var(--muted)}.prototype-link{color:var(--blue);text-decoration:underline;text-underline-offset:3px}.design-note{padding:40px 0 70px;max-width:850px}.design-note h1{font-size:44px}.design-note h2{font:600 22px "Segoe UI",Arial,sans-serif;margin-top:32px}.design-note p,.design-note li{color:var(--muted);font-size:16px}.design-note table{width:100%;border-collapse:collapse;font-size:14px;margin:20px 0}.design-note th,.design-note td{text-align:left;border-bottom:1px solid var(--line);padding:12px 10px;vertical-align:top}.design-note th{color:var(--ink)}.design-note a{color:var(--blue);text-decoration:underline;text-underline-offset:4px}.swatches{display:flex;gap:20px;margin:25px 0}.swatch{flex:1}.swatch i{height:80px;border-radius:6px;display:block;margin-bottom:8px}.swatch span{font-size:12px}.prototype-banner{font-size:12px;color:var(--muted);border-bottom:1px solid var(--line);padding:8px 0;background:#eef1f3}.prototype-banner .wrap{display:flex;justify-content:space-between;gap:18px}.prototype-banner a{color:var(--blue);text-decoration:underline}
mjx-container[display="true"]{max-width:100%;overflow-x:auto;overflow-y:hidden;padding:6px 2px}mjx-container svg{max-width:none}.prose .legacy-formula,.task-body .legacy-formula{display:inline-block;max-width:100%;vertical-align:middle}
@media(min-width:1001px){.nav-panel{display:none!important}}
@media(max-width:1120px){.masthead{gap:24px}.desktop-nav{gap:18px}.desktop-nav a{font-size:13px}.brand{width:155px;flex-basis:155px}.brand img{width:155px}.login-link{padding:9px 4px}.reader-layout{gap:32px;grid-template-columns:minmax(0,1fr) 195px}.catalog-layout{gap:30px}}
@media(max-width:1000px){.wrap{width:calc(100% - 48px)}.desktop-nav{display:none}.menu-button{display:inline-flex}.masthead{height:86px}.brand{width:167px;flex-basis:167px}.brand img{width:167px}.header-tools{gap:4px}.login-link{padding:9px 10px}.hero .wrap{min-height:355px;grid-template-columns:1.25fr 1fr}.orbit-art{height:310px}.hero-copy{padding:38px 0}.hero h1{font-size:48px}.path+.path{padding-left:23px}.path{gap:12px}.path strong{font-size:15px}.path small{font-size:12px}.path .arrow{margin-right:12px}.featured-grid{gap:26px}.cover-copy{padding:22px}.compact-story h3{font-size:21px}.learn-panel{gap:30px;padding:30px}.reader-side{display:none}.reader-intro{max-width:760px}.reader-layout{display:block;max-width:760px;margin:auto}.mobile-toc{display:block;border:1px solid var(--line);border-radius:6px;background:#fff;padding:0 15px;margin:15px 0 24px;font-size:14px}.mobile-toc summary{padding:12px 0;font-weight:600;min-height:48px}.mobile-toc ol{padding:0 0 10px 20px}.mobile-toc li{margin:7px 0}.mobile-toc a{color:var(--blue)}.catalog-layout{grid-template-columns:185px minmax(0,1fr);gap:25px}.material-row h2{font-size:22px}.tasks-layout{grid-template-columns:210px minmax(0,1fr);gap:25px}.task-card{padding:24px}.task-section-heading h2{font-size:29px}}
@media(max-width:700px){html{scroll-padding-top:90px}.wrap{width:calc(100% - 36px)}.masthead{height:76px;gap:14px}.brand{width:143px;flex-basis:143px}.brand img{width:143px}.header-tools{gap:1px}.login-link{display:none}.menu-button{font-size:13px;gap:5px}.menu-button .icon{width:19px}.prototype-banner .wrap{gap:10px;font-size:10px}.prototype-banner{padding:6px 0}.hero .wrap{display:block;min-height:0}.hero-copy{padding:32px 0 39px;position:relative;z-index:2}.hero .eyebrow{font-size:10px;letter-spacing:1.1px;margin-bottom:18px}.hero h1{font-size:43px;letter-spacing:-1.2px;max-width:13ch;margin-bottom:18px}.hero p{font-size:15px;line-height:1.7;max-width:29ch;color:#d8e4ef}.hero .button-row{gap:9px}.hero .button{font-size:13px;padding:10px 14px;min-height:44px}.orbit-art{position:absolute;width:250px;height:250px;right:-85px;top:60px;opacity:.26}.path-grid{grid-template-columns:1fr}.path{padding:15px 0;min-height:77px;gap:17px}.path+.path{border-left:0;border-top:1px solid var(--line);padding:15px 0}.path .index{font-size:25px}.path strong{font-size:16px}.path small{font-size:12px}.path .arrow{margin-right:6px}.home-section{padding:36px 0}.section-head{margin-bottom:22px;align-items:end;gap:14px}.section-head h2{font-size:31px}.section-head a{font-size:12px;max-width:92px;text-align:right}.section-head .eyebrow{font-size:10px;margin-bottom:6px}.archive-caption{font-size:12px;line-height:1.7}.featured-grid{grid-template-columns:1fr;gap:25px}.cover-image{aspect-ratio:1.8}.cover-copy{padding:22px}.cover-copy h3{font-size:28px}.cover-copy p{font-size:14px}.compact-story{margin-bottom:18px;padding-bottom:20px}.compact-story h3{font-size:21px}.compact-story p{font-size:14px}.mini-story{grid-template-columns:1fr 67px;gap:16px}.learn-panel{grid-template-columns:1fr;gap:15px;padding:24px 22px}.learn-panel h2{font-size:28px}.learn-panel p{font-size:14px;margin-bottom:0}.learn-links a{font-size:14px;min-height:69px}.learn-links small{font-size:12px}.page-intro{padding:27px 0 23px}.page-intro h1{font-size:36px;letter-spacing:-.7px}.page-intro>p{font-size:14px;line-height:1.75}.breadcrumb{font-size:11px;margin-bottom:18px}.catalog-layout{display:block;padding-bottom:42px}.filter-aside{position:static;margin-bottom:20px}.filter-aside h2,.archive-info{display:none}.filter-section{padding:0;border:0;margin:0 0 15px}.filter-label{display:none}.type-filters{flex-direction:row;gap:5px;padding:4px;background:white;border:1px solid var(--line);border-radius:7px}.filter-type{flex:1;justify-content:center;gap:7px;font-size:13px;padding:8px 7px}.filter-type span{font-size:10px}.secondary-filters{display:grid;grid-template-columns:1fr 1fr;gap:10px}.filter-aside select{font-size:12px}.catalog-toolbar{display:block;margin-bottom:13px}.catalog-search{min-height:46px}.catalog-search input{font-size:14px;min-height:44px}.sort-select{width:100%;font-size:12px;min-height:42px;margin-top:10px;padding:9px 11px}.catalog-count{font-size:12px;margin-bottom:12px}.catalog-list{padding:0 18px}.material-row{grid-template-columns:1fr;gap:0;padding:22px 0;position:relative}.row-image-link{display:none}.material-row h2{font-size:22px;line-height:1.35;letter-spacing:-.3px;margin-bottom:11px}.material-row p{font-size:13px;margin-bottom:12px}.card-meta{font-size:11px;gap:6px}.row-bottom{font-size:11px;flex-wrap:wrap}.pagination{font-size:11px;gap:8px;flex-wrap:wrap}.page-buttons{gap:5px}.page-button{height:39px;min-width:39px;font-size:12px}.reader-intro{padding:28px 0 18px}.reader-intro h1{font-size:35px;letter-spacing:-.65px;line-height:1.18;max-width:100%;margin-bottom:20px}.reader-meta{font-size:12px;gap:7px 18px;margin-bottom:15px}.reader-kicker{margin-bottom:15px}.reader-kicker .eyebrow{font-size:10px}.archive-line{font-size:12px;line-height:1.7;padding-left:11px}.reader-layout{padding-bottom:40px;max-width:none}.reader-sheet{padding:22px 19px;margin-inline:-5px;border-radius:7px}.reader-controls{margin-bottom:22px;font-size:11px;gap:9px;padding-bottom:12px}.font-controls{gap:0}.font-controls button{min-width:32px}.prose{font-size:calc(var(--reading-size) - 1px);line-height:1.82}.prose h2,.prose h3{font-size:23px;margin:1.5em 0 .7em;scroll-margin-top:100px}.prose table{font-size:12px}.editorial-note{padding:20px 17px;font-size:14px;margin-bottom:27px}.editorial-note h2{font-size:19px;line-height:1.4}.editorial-note .note-date{font-size:11px}.editorial-note ul{font-size:12px;padding-left:15px}.editorial-note summary{font-size:13px}.reader-related{padding:0 0 36px}.reader-related-grid{grid-template-columns:1fr;gap:13px}.reader-related article{padding:19px}.reader-related h3{font-size:19px}.tasks-layout{display:block;padding-bottom:38px}.chapter-nav{display:none}.mobile-chapters{display:block;margin-bottom:19px;border:1px solid var(--line);border-radius:6px;background:white;padding:0 15px;font-size:13px}.mobile-chapters summary{min-height:46px;padding:11px 0;font-weight:600}.mobile-chapters ol{padding:0 0 10px 18px;margin:0}.mobile-chapters li{margin:12px 0}.mobile-chapters a{color:var(--blue)}.task-section-heading h2{font-size:27px;line-height:1.24}.task-section-heading{gap:12px;margin-bottom:20px}.task-section-heading p{font-size:13px}.task-section-heading .pill{font-size:11px;white-space:nowrap;padding:4px 7px}.task-toolbar{gap:5px;margin-bottom:15px}.level-button{font-size:11px;padding:8px 10px;min-height:40px}.task-progress{margin-left:0;width:100%;margin-top:6px;font-size:11px}.task-card{padding:21px 19px;margin-bottom:15px}.task-top{margin-bottom:16px;gap:8px}.task-top h3{font-size:18px}.task-top .pill{font-size:10px;padding:4px 7px}.task-body{font-size:17px;line-height:1.8;margin-bottom:18px}.task-knowledge{font-size:12px;padding:10px 12px;margin-bottom:17px}.task-bottom{font-size:10px;gap:10px;line-height:1.5}.task-bottom label{gap:6px;min-height:38px}.task-bottom input{width:17px;height:17px;flex-shrink:0}.task-bottom a{font-size:10px}.task-help{font-size:12px}.site-footer{padding:27px 0 22px}.footer-main{display:block}.footer-summary{font-size:12px}.footer-brand{font-size:22px}.footer-links{gap:9px 20px;font-size:12px;margin-top:22px}.footer-bottom{font-size:10px;gap:10px;margin-top:24px;line-height:1.7}.footer-bottom span{max-width:25ch}.design-note{padding:28px 0 45px}.design-note h1{font-size:35px}.design-note p,.design-note li{font-size:14px}.design-note table{font-size:12px}.design-note th,.design-note td{padding:10px 4px}.swatches{gap:12px}.swatch i{height:55px}}
@media(max-width:360px){.wrap{width:calc(100% - 28px)}.brand{width:131px;flex-basis:131px}.brand img{width:131px}.menu-button{font-size:12px;min-width:42px}.hero h1{font-size:39px}.hero .button-row{gap:7px}.hero .button{padding:10px 12px;font-size:12px}.reader-intro h1{font-size:31px}.task-top .pill{font-size:9px}.task-body{font-size:16px}.task-card{padding:18px 15px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
@media print{.site-header,.site-footer,.prototype-banner,.reader-side,.reader-controls,.reader-end,.mobile-toc,.reader-related{display:none!important}body{background:white;color:black}.wrap,.reader-intro{width:100%;max-width:100%}.reader-layout{display:block;padding:0}.reader-sheet{padding:0;border:0}.reader-intro{padding:0}.reader-intro h1{font-size:30px}.prose{font-size:12pt;line-height:1.55}.prose a{color:black}.editorial-note{break-inside:avoid}.task-card{break-inside:avoid}}

.hero .eyebrow{max-width:none}.material-row p{display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}

@media(max-width:700px){.catalog-search input,.filter-aside select,.sort-select{font-size:16px}}

@media(min-width:1121px){.brand{width:206px;flex-basis:206px}.brand img{width:206px}}
@media(min-width:701px) and (max-width:1000px){.brand{width:180px;flex-basis:180px}.brand img{width:180px}}
@media(min-width:361px) and (max-width:700px){.brand{width:173px;flex-basis:173px}.brand img{width:173px}}
@media(max-width:700px){.task-bottom{font-size:12px;flex-wrap:wrap}.task-bottom a{font-size:12px}.task-bottom label{min-height:44px}.task-knowledge{font-size:13px}.task-top .pill{font-size:11px}.reader-meta{font-size:13px}}

.cover-story{align-self:start}.cover-image{aspect-ratio:1.5}.home-signature{font-size:12px;color:var(--muted);margin:14px 0 8px}

/* A spatial embedding replaces the earlier orbital decoration. */
.curvature-figure{margin:0;min-width:0}.curvature-art{display:block;width:100%;height:auto}.curvature-figure figcaption{font:11px/1.6 "Segoe UI",Arial,sans-serif;color:#b6c9e1;text-align:right;padding:0 18px 15px;letter-spacing:.35px}.hero .curvature-figure{width:112%;margin-left:-6%;align-self:center}.prototype-banner a:hover{text-decoration:underline}.prototype-banner .variant-links{display:flex;align-items:center;gap:13px;flex-wrap:wrap}.prototype-banner a[aria-current=page]{font-weight:700;text-decoration:underline;text-underline-offset:3px}
.brand-word{font:700 34px/1.15 Georgia,serif;letter-spacing:-1.4px;color:var(--blue)}.brand-note{display:block;font-size:9px;line-height:1.6;letter-spacing:.8px;text-transform:uppercase;color:var(--muted);margin-top:4px}
.chapter-nav .all-chapters{display:block}
h1{overflow-wrap:anywhere}.prose mjx-container[jax="SVG"]:not([display="true"]){display:inline-block;max-width:100%;overflow-x:auto;overflow-y:hidden;vertical-align:middle}
@media(max-width:700px){.hero .curvature-figure{width:100%;margin:0;position:relative;padding-bottom:15px}.hero-copy{padding-bottom:16px}.curvature-figure figcaption{font-size:10px;text-align:left;padding-inline:0}.prototype-banner .variant-links{gap:9px}.prototype-banner .wrap{flex-wrap:wrap}}

/* Native PHP templates use the same design system as the selected prototype. */
.filter-type[aria-current=page]{background:var(--blue);color:white}.archive-filter-form input,.archive-filter-form select{width:100%;min-height:44px;border:1px solid var(--line);border-radius:5px;background:#fff;padding:9px;color:var(--ink)}.filter-actions{display:flex;align-items:center;gap:18px;margin-top:18px}.catalog-results{min-width:0}.material-row picture,.material-row .row-image-link img{display:block;width:80px;height:80px;object-fit:cover;border-radius:6px}.material-row .row-image-link img{float:none!important;margin:0!important}.archive-notice{color:var(--muted);font-size:14px;max-width:80ch}.archive-notice p{margin:7px 0}.navigation{display:flex;flex-wrap:wrap;align-items:center;gap:7px;margin:28px 0 45px}.page-nav,.page-navigation,.page-gap{display:inline-flex;align-items:center;justify-content:center;min-width:42px;min-height:44px;padding:8px 12px;border-radius:5px;font-size:14px}.page-nav{border:1px solid var(--line);background:white}.page-nav:hover{border-color:var(--blue)}.page-navigation{background:var(--blue);color:white}.page-direction{min-width:auto}.breadcrumbs ol{display:flex;flex-wrap:wrap;gap:8px;list-style:none;padding:0;font-size:12px;color:var(--muted)}.breadcrumbs li+li:before{content:' / ';margin-right:8px}.reader-intro .title{font:inherit}.reader-intro h1.title{font:700 51px/1.17 Georgia,serif;max-width:22ch;letter-spacing:-1.2px;margin:18px 0 25px}.legacy-reader .dialog_main{padding:0;border:0;background:none}.legacy-reader .meta1,.legacy-reader .meta3{font-size:13px;color:var(--muted);border-top:1px solid var(--line);padding-top:16px}.legacy-reader .meta1 a{display:inline-block;margin:4px 4px 4px 0;padding:2px 9px;border-radius:20px;background:var(--soft-blue);text-decoration:none;font-size:12px}.legacy-reader .editorial-note{font-size:16px;margin-bottom:28px}.editorial-note h2{font:700 24px/1.3 Georgia,serif}.review-date,.review-scope{font-size:13px!important;color:var(--muted)}.editorial-note details{border-top:1px solid var(--line);padding-top:10px}.editorial-note summary{cursor:pointer;min-height:40px}.reader-side .side-source{display:block;margin:18px 0}.legacy-reader #comments{margin-top:35px;border-top:1px solid var(--line)}.dialog-comments{padding:20px 0;border-bottom:1px solid var(--line);font-size:16px}.com_title{font-weight:700}.dialog-comments .meta_index{font-size:13px;color:var(--muted)}.reader-sheet,.prose,.generic-sheet{min-width:0}.prose .legacy-formula,.task-body .legacy-formula{max-width:100%}.prose mjx-container,.task-body mjx-container{max-width:100%;overflow-x:auto;overflow-y:hidden}.task-body mjx-container[jax=SVG]:not([display=true]){display:inline-block;vertical-align:middle}.legacy-reader iframe{width:100%;max-width:100%;aspect-ratio:16/9;height:auto}.legacy-reader table,.generic-sheet table{max-width:100%;width:auto;display:block;overflow-x:auto}.prose img{height:auto;max-width:100%}.prose form input:not([type=hidden]),.prose form textarea{max-width:100%;min-height:44px;border:1px solid var(--line);border-radius:4px;padding:8px;font:inherit}.prose form input[type=submit],.prose button{cursor:pointer;background:var(--blue);color:white;border:0;border-radius:5px;padding:10px 18px}.generic-layout{display:grid;grid-template-columns:minmax(0,830px) minmax(180px,1fr);gap:50px;align-items:start;padding-bottom:65px}.generic-sheet{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:42px 50px}.generic-sheet .dialog_main{border:0;padding:0;background:transparent;margin:0 0 25px}.generic-side{position:sticky;top:110px;font-size:14px}.generic-side h2{font:700 22px Georgia,serif}.generic-side a{display:block;padding:12px 0;border-bottom:1px solid var(--line)}.generic-sheet h2{font:700 30px/1.3 Georgia,serif}.generic-sheet .title_article{font:700 23px/1.3 Georgia,serif}.generic-sheet .dialog_main:has(.title_article){padding:24px 0;border-bottom:1px solid var(--line)}.generic-sheet form{margin:25px 0}.generic-sheet form label{font-weight:600}.generic-sheet form button{min-height:44px}.generic-sheet input[type=search]{width:100%}.task-filter-form{display:flex;gap:12px;align-items:end;margin:25px 0 15px;flex-wrap:wrap}.task-filter-form label{font-size:13px;font-weight:600;flex:1;min-width:180px}.task-filter-form input:not([type=hidden]),.task-filter-form select{display:block;width:100%;min-height:44px;font:inherit;background:white;border:1px solid var(--line);border-radius:4px;padding:9px}.task-top h2{margin:0;font:700 23px Georgia,serif}.task-permalink{color:var(--muted);font-size:13px;padding:6px}.task-guidance{font-size:14px;background:var(--soft-blue);padding:12px 16px;border-radius:4px;margin:15px 0 20px}.task-guidance p{margin:0 0 4px}.task-level-intro{color:#285b43}.task-level-university{color:var(--blue)}.task-level-advanced{color:#714800}.task-section-guidance{padding:22px 28px;border:1px solid #cfdae8;border-left:4px solid var(--blue);border-radius:5px;background:#fff;font-size:14px}.task-section-guidance h2{font-size:23px}.task-section-guidance p{margin:10px 0}.chapter-nav small{display:block;font-size:11px;color:var(--muted);margin-top:4px}.chapter-nav li a{min-width:0}.task-body{overflow-wrap:anywhere}.home-news{padding-top:0}.account-dropdown{position:relative;font-size:13px}.account-dropdown summary{display:flex;align-items:center;gap:6px;cursor:pointer;min-height:44px;max-width:120px}.account-dropdown summary span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.account-dropdown>div{position:absolute;right:0;top:48px;width:270px;padding:18px 22px;background:#fff;border:1px solid var(--line);border-radius:6px;box-shadow:0 10px 35px #142c4620;z-index:30}.account-dropdown p{margin:8px 0}.analytics-choice{position:fixed;bottom:18px;left:18px;max-width:480px;padding:22px;background:white;border:1px solid var(--line);box-shadow:0 8px 35px #142c4620;border-radius:8px;z-index:90;font-size:14px}.analytics-choice button,#analytics-preferences{font:inherit;cursor:pointer;border:1px solid var(--line);border-radius:4px;padding:8px}.analytics-choice button{background:var(--blue);color:white;margin:4px}.analytics-choice p{margin:0 0 12px}[hidden]{display:none!important}
@media(max-width:1000px){.generic-layout{grid-template-columns:minmax(0,1fr) 190px;gap:25px}.generic-sheet{padding:32px 30px}.reader-intro h1.title{font-size:43px}.brand{flex-shrink:0}}
@media(max-width:700px){.catalog-layout{display:block}.filter-aside{border:1px solid var(--line);padding:20px;border-radius:8px;background:white;margin-bottom:25px}.archive-filter-form{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:0 12px}.archive-filter-form .filter-section:first-child,.filter-actions{grid-column:1/-1}.archive-filter-form input,.archive-filter-form select{font-size:16px}.archive-filter-form .filter-section{min-width:0}.filter-label{font-size:13px}.archive-info{font-size:12px}.generic-layout{display:block;padding-bottom:35px}.generic-sheet{padding:24px 19px}.generic-side{position:static;margin-top:28px}.generic-sheet h2{font-size:24px}.reader-intro h1.title{font-size:34px;letter-spacing:-.5px;max-width:none}.reader-meta{gap:8px}.reader-intro .breadcrumbs{font-size:11px}.task-top h2{font-size:20px}.task-filter-form{display:block}.task-filter-form label{display:block;margin:12px 0}.task-filter-form input,.task-filter-form select{font-size:16px}.task-filter-form button{width:100%}.task-section-guidance{padding:18px}.task-guidance{font-size:13px}.navigation{gap:5px}.page-nav,.page-navigation{font-size:12px;padding:7px 10px;min-width:38px}.account-dropdown summary span{display:none}.account-dropdown summary{min-width:32px}.analytics-choice{left:12px;right:12px;bottom:12px;max-width:none}.prose form table td{padding:6px;white-space:normal}.prose form input:not([type=hidden]),.prose form textarea{font-size:16px}.prose .title_article{font-size:20px}}
@media(max-width:360px){.reader-intro h1.title{font-size:30px}.archive-filter-form{display:block}.filter-actions{gap:14px}.generic-sheet{padding:20px 15px}.page-direction{font-size:11px}.brand-word{font-size:30px}.brand-note{font-size:8px}}
.legacy-reader .publication-footer{display:flex;align-items:center;flex-wrap:wrap;gap:8px 18px;margin:18px 0 20px;padding:10px 0 0;border-top:1px solid var(--line);font:13px/1.6 "Segoe UI",Arial,sans-serif;color:var(--muted);scroll-margin-top:130px}
.publication-stats{display:flex;align-items:baseline;flex-wrap:wrap;gap:6px 16px;margin:0}
.publication-field{display:inline-flex;align-items:baseline;gap:4px;min-width:0}
.publication-field dt{font-size:13px;font-weight:400}
.publication-field dt::after{content:":"}
.publication-field dd{margin:0;font-size:13px;font-weight:500;color:var(--ink)}
.publication-date dt{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.publication-date dd{font-weight:400;color:var(--muted)}
.publication-counter dd{font-variant-numeric:tabular-nums}
.publication-actions{margin-left:auto;min-width:0}
.prose .publication-comment-link{display:inline-flex;align-items:center;justify-content:center;min-width:24px;min-height:24px;margin-left:-4px;padding:0 4px;text-decoration:none}
.prose .publication-comment-link:hover{text-decoration:underline}
.publication-share{display:flex;align-items:flex-start;flex-direction:column;gap:4px;max-width:100%}
.publication-share .share-button{min-height:32px;padding:4px 0;gap:6px;border:0;border-radius:3px;background:transparent;color:var(--blue);font:500 12px/1.5 "Segoe UI",Arial,sans-serif;white-space:nowrap}
.publication-share .share-button:hover{background:transparent;text-decoration:underline;text-underline-offset:3px}
.share-button .icon{width:15px;height:15px;flex-shrink:0}
.publication-share .share-status{max-width:100%;font-size:12px;color:var(--blue-dark);overflow-wrap:anywhere}
.share-status:empty{display:none}
.legacy-reader #comments{scroll-margin-top:120px}
.compact-story.has-thumbnail{display:grid;grid-template-columns:80px minmax(0,1fr);gap:18px;align-items:start}
.compact-story-copy{min-width:0}
.compact-story .story-image-link{display:block;border-radius:6px;overflow:hidden;margin-top:3px}
.compact-story .story-image-link picture,.compact-story .story-image-link img{display:block;width:80px;height:80px;object-fit:cover}
.compact-story .story-image-link img{float:none!important;margin:0!important}
.compact-story-copy .home-signature{margin:10px 0 6px}
@media(max-width:700px){
 .legacy-reader .publication-footer{gap:8px 14px;margin:16px 0 18px;scroll-margin-top:105px}
 .publication-stats{gap:5px 14px}
 .publication-actions{margin-left:0}
 .legacy-reader #comments{scroll-margin-top:105px}
 .compact-story.has-thumbnail{grid-template-columns:64px minmax(0,1fr);gap:14px}
 .compact-story .story-image-link picture,.compact-story .story-image-link img{width:64px;height:64px}
}
@media(max-width:360px){.compact-story.has-thumbnail{grid-template-columns:56px minmax(0,1fr);gap:12px}.compact-story .story-image-link picture,.compact-story .story-image-link img{width:56px;height:56px}}
@media print{.legacy-reader .publication-footer{break-inside:avoid}.publication-actions{display:none}}