:root{color-scheme:light;--bg:#fff;--surface:#f6f9f7;--soft:#edf4f0;--text:#203632;--muted:#5e6c67;--accent:#075b53;--line:#dce5df;--shadow:0 14px 35px #18382e14}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:30px}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:17px;line-height:1.65}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline;text-underline-offset:4px}button,input{font:inherit}button{cursor:pointer}button,a,input{touch-action:manipulation}a:focus-visible,button:focus-visible,input:focus-visible{outline:3px solid #b47b22;outline-offset:4px}h1,h2,h3,p{margin-top:0}h1,h2,h3{line-height:1.2;letter-spacing:-.035em}p{margin-bottom:1.2em}svg{width:24px;height:24px;flex-shrink:0}.wrap{max-width:1180px;margin-inline:auto;padding-inline:24px}.site-header{border-bottom:1px solid var(--line);background:var(--bg)}.header-inner{max-width:1360px;margin:auto;padding:25px 40px;display:flex;align-items:center;gap:24px;min-height:105px}.brand{display:flex;align-items:center;gap:13px;font-weight:650;font-size:15px;line-height:1.22;letter-spacing:-.3px;color:var(--text)}.brand:hover{text-decoration:none}.brand-mark{width:39px;height:43px;background:var(--accent);border-radius:4px;color:var(--bg);font-family:Georgia,serif;font-size:40px;line-height:1.08;text-align:center;font-weight:400;position:relative;overflow:hidden}.brand-mark span{font-family:Arial,sans-serif;font-size:23px;position:absolute;right:2px;top:3px}.header-divider{height:28px;width:1px;background:var(--line)}.kb-label{font-size:13px;color:var(--muted)}.top-nav{margin-left:auto;display:flex;gap:29px;font-size:14px;font-weight:500}.top-nav a{color:var(--text);padding-block:9px}.theme-button{width:44px;height:44px;border:1px solid var(--line);border-radius:50%;background:var(--bg);color:var(--text);font-size:24px}.hero{background:var(--surface);border-bottom:1px solid var(--line);position:relative;overflow:hidden}.hero-inner{max-width:880px;margin:auto;text-align:center;padding:62px 24px 54px;position:relative;z-index:1}.eyebrow{font-size:11px;letter-spacing:1.9px;font-weight:650;color:var(--accent);line-height:1.5;display:inline-block}.status-dot{display:inline-block;width:6px;height:6px;background:var(--accent);border-radius:50%;margin-right:7px;vertical-align:2px}.hero h1{font-size:54px;font-weight:550;margin:18px 0 16px;letter-spacing:-2.2px}.hero p{font-size:17px;line-height:1.7;color:var(--muted);margin-bottom:27px}.search{position:relative;display:flex;align-items:center;background:var(--bg);border:1px solid #b6c9c0;border-radius:7px;box-shadow:0 3px 4px #16392c04;text-align:left}.hero-search{max-width:650px;margin:0 auto}.search>svg{margin-left:21px;color:var(--accent);width:21px}.search input{border:0;background:transparent;color:var(--text);padding:19px 16px;width:100%;min-width:0;outline-offset:-4px;border-radius:7px;font-size:16px}.search input::placeholder{color:var(--muted);opacity:1}.search-hint{color:var(--muted);border:1px solid var(--line);border-radius:4px;font-size:15px;line-height:24px;width:28px;text-align:center;margin-right:17px}.search-examples{display:flex;justify-content:center;gap:8px;font-size:12px;color:var(--muted);margin-top:17px;flex-wrap:wrap}.search-examples a{border-bottom:1px solid #b4c9c1}.hero-decoration{position:absolute;width:350px;height:350px;right:-200px;top:15px;transform:rotate(-20deg);opacity:.5}.hero-decoration span{display:block;border:1px solid #b8d0c5;border-radius:50%;position:absolute;inset:0}.hero-decoration span:nth-child(2){inset:35px}.hero-decoration span:nth-child(3){inset:70px}.section-heading{display:flex;justify-content:space-between;align-items:flex-end;margin-bottom:27px;gap:16px}.section-heading h2{font-size:30px;font-weight:550;margin:10px 0 0}.section-note{font-size:12px;color:var(--muted);padding-bottom:5px}.browse{padding-top:49px;padding-bottom:50px}.category-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:17px}.category-card{border:1px solid var(--line);padding:23px 22px 25px;border-radius:7px;display:block;color:var(--text);transition:border-color .15s,background .15s;min-height:205px}.category-card:hover{border-color:var(--accent);background:var(--surface);text-decoration:none}.card-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:22px}.category-icon{display:inline-flex;align-items:center;justify-content:center;background:var(--soft);color:var(--accent);width:42px;height:42px;border-radius:9px}.card-count{font-size:11px;color:var(--muted)}.category-card h3{font-size:18px;font-weight:600;display:flex;justify-content:space-between;gap:8px;margin-bottom:9px;letter-spacing:-.4px}.category-card h3>span{font-weight:400;font-size:17px;color:var(--muted)}.category-card p{font-size:14px;line-height:1.65;color:var(--muted);margin:0}.starting{border-top:1px solid var(--line);display:grid;grid-template-columns:1fr 1fr;gap:70px;padding-top:43px;padding-bottom:46px}.starting h2{font-size:30px;font-weight:550;margin:11px 0 15px}.starting p{font-size:14px;color:var(--muted)}.text-link{font-size:14px;font-weight:600}.text-link span{margin-left:12px}.featured-link{display:flex;gap:16px;align-items:center;padding:18px 0;border-bottom:1px solid var(--line);color:var(--text);font-size:15px;line-height:1.5}.featured-link:last-child{border-bottom:0}.featured-link>span:last-child{margin-left:auto;color:var(--accent)}.small-number{font-size:11px;align-self:flex-start;padding-top:3px;color:var(--muted)}.featured-link small{display:block;font-size:11px;color:var(--muted);margin-top:4px}.worksheet-strip{display:flex;gap:19px;align-items:center;margin-bottom:60px;background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:25px;max-width:1132px}.worksheet-strip h2{font-size:18px;margin:0 0 5px;font-weight:600}.worksheet-strip p{font-size:13px;color:var(--muted);margin:0}.worksheet-strip>a{margin-left:auto;white-space:nowrap}footer{border-top:1px solid var(--line);background:var(--surface)}.footer-inner{max-width:1180px;padding:31px 24px;margin:auto}.footer-top,.footer-bottom{display:flex;justify-content:space-between;gap:20px}.footer-top{font-size:12px;margin-bottom:18px}.footer-brand{font-size:13px;font-weight:600;color:var(--text)}.footer-top>span,.footer-bottom>span{color:var(--muted)}.footer-bottom{font-size:11px}.footer-bottom a{color:var(--muted)}.header-search-row{max-width:850px;margin:0 auto;padding:0 24px 20px}.header-search input{padding:11px 16px}.results{position:absolute;z-index:20;top:calc(100% + 8px);left:0;right:0;background:var(--bg);box-shadow:var(--shadow);border:1px solid var(--line);border-radius:8px;padding:8px;max-height:430px;overflow-y:auto}.results a{display:block;padding:12px;color:var(--text);font-size:15px;line-height:1.4;border-radius:4px}.results a:hover,.results a:focus{background:var(--soft)}.results small{display:block;color:var(--muted);font-size:12px;margin-top:4px}.results p{font-size:14px;padding:12px;margin:0}.breadcrumbs{display:flex;flex-wrap:wrap;gap:10px;font-size:12px;color:var(--muted);padding:27px 0 33px}.breadcrumbs a{color:var(--muted)}.category-page{max-width:990px;padding-bottom:80px;min-height:65vh}.category-title{padding:14px 0 25px}.category-title>.category-icon{margin-right:14px;vertical-align:middle}.category-title h1{font-size:45px;margin:24px 0 15px;font-weight:550}.category-title p{color:var(--muted);font-size:19px}.article-list{border-top:1px solid var(--line);margin-bottom:30px}.article-row{padding:27px 0;display:flex;justify-content:space-between;gap:24px;border-bottom:1px solid var(--line);color:var(--text)}.article-row h2{font-size:21px;margin-bottom:10px;font-weight:550}.article-row p{font-size:16px;color:var(--muted);margin:0}.article-row>span{color:var(--accent)}.article-wrap{max-width:1400px;margin:auto;padding:0 40px 80px}.article-layout{display:grid;grid-template-columns:205px minmax(0,710px) 175px;gap:45px;justify-content:center}.article-sidebar,.toc{align-self:start;position:sticky;top:28px;font-size:13px;line-height:1.5}.article-sidebar nav{display:grid;gap:5px;margin:18px 0 30px}.article-sidebar nav a{padding:11px 12px;color:var(--muted);border-radius:5px}.article-sidebar nav [aria-current]{background:var(--soft);color:var(--accent);font-weight:600}.back-link{font-weight:600}.sidebar-all{font-size:12px}.toc{border-left:1px solid var(--line);padding-left:19px}.toc .eyebrow{font-size:10px;letter-spacing:1.4px}.toc nav{display:grid;gap:15px;margin-top:18px}.toc a{color:var(--muted);font-size:12px}.toc a.active{color:var(--accent);font-weight:650}article h1{font-size:43px;line-height:1.15;font-weight:550;margin:13px 0 19px}article h2{font-size:27px;font-weight:550;margin:38px 0 18px}article p{font-size:18px;line-height:1.8}.article-meta{font-size:12px;color:var(--muted);display:flex;gap:9px;flex-wrap:wrap;margin-bottom:30px}.article-intro{border-top:1px solid var(--line);padding-top:27px}.article-intro p:first-child{font-size:19px}.process{display:flex;gap:13px;align-items:center;justify-content:space-between;background:var(--surface);border:1px solid var(--line);padding:22px 17px;border-radius:6px;font-size:13px;color:var(--accent);margin:25px 0}.process b{font-weight:400}li{padding-left:5px;margin-bottom:12px}dt{font-weight:650;margin-top:20px}dd{margin:3px 0 15px;color:var(--muted)}.download{display:inline-block;border-bottom:1px solid var(--accent);padding:7px 0}.feedback{border-block:1px solid var(--line);margin:45px 0 35px;padding:25px 0;display:flex;gap:20px;align-items:center;flex-wrap:wrap;font-size:15px}.feedback>div{display:flex;gap:8px}.feedback button{border:1px solid var(--line);border-radius:5px;padding:9px 22px;background:var(--bg);color:var(--accent);min-height:44px}.feedback button[aria-pressed=true]{background:var(--accent);color:var(--bg)}.feedback .feedback-status{width:100%;font-size:12px;color:var(--muted);margin:-8px 0 0}.related h2{font-size:23px;margin-top:0}.related a{display:flex;justify-content:space-between;gap:15px;border-bottom:1px solid var(--line);font-size:15px;padding:15px 0}.skip{position:fixed;top:-80px;left:16px;padding:12px;z-index:50;background:var(--bg);border:2px solid var(--accent)}.skip:focus{top:12px}.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}[hidden]{display:none!important}
:root[data-theme=dark]{color-scheme:dark;--bg:#15221f;--surface:#1b2b26;--soft:#243b32;--text:#e3ece6;--muted:#abbdb3;--accent:#87d4bf;--line:#364b40;--shadow:0 14px 35px #0005}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]){color-scheme:dark;--bg:#15221f;--surface:#1b2b26;--soft:#243b32;--text:#e3ece6;--muted:#abbdb3;--accent:#87d4bf;--line:#364b40;--shadow:0 14px 35px #0005}}
@media(min-width:1600px){.hero-inner{padding-block:75px}.browse{padding-top:60px}}
@media(max-width:1150px){.article-layout{grid-template-columns:180px minmax(0,710px);gap:30px}.toc{display:none}.kb-label,.header-divider{display:none}.category-grid{gap:14px}.category-card{padding:20px 17px}.worksheet-strip{margin-inline:24px}}
@media(max-width:800px){.header-inner{padding:18px 24px;gap:18px;min-height:85px}.top-nav{gap:18px;font-size:12px}.hero h1{font-size:43px}.hero-inner{padding-top:48px}.category-grid{grid-template-columns:repeat(2,1fr)}.category-card{min-height:185px}.starting{gap:35px}.article-wrap{padding-inline:24px}.article-layout{display:block;max-width:710px;margin:auto}.article-sidebar{position:static;margin-bottom:30px}.article-sidebar nav{display:none}.sidebar-all{display:none}.worksheet-strip{flex-wrap:wrap}.worksheet-strip>a{margin-left:61px}.section-note{display:none}.article-wrap .breadcrumbs{padding-bottom:20px}}
@media(max-width:520px){.wrap{padding-inline:16px}.header-inner{padding:15px 16px;gap:12px}.brand{font-size:12px;gap:9px}.brand-mark{width:32px;height:36px;font-size:34px}.brand-mark span{font-size:19px}.top-nav{margin-left:auto}.top-nav a{font-size:12px;min-height:44px;display:flex;align-items:center}.top-nav a:last-child{display:none}.theme-button{width:38px;min-width:38px;height:44px;font-size:21px;border:0}.hero-inner{padding:40px 16px 35px}.hero h1{font-size:36px;letter-spacing:-1.5px;margin-top:18px}.eyebrow{font-size:9px;letter-spacing:1.3px}.hero p{font-size:15px}.search input{font-size:15px;padding:17px 10px}.search>svg{margin-left:15px;width:19px}.search-hint{display:none}.search-examples{font-size:11px;gap:5px;margin-top:16px}.browse{padding-top:32px;padding-bottom:33px}.section-heading h2{font-size:26px}.category-grid{gap:10px}.category-card{padding:17px 13px;min-height:214px}.category-card h3{font-size:16px}.category-card p{font-size:13px}.card-top{margin-bottom:19px}.card-count{font-size:10px}.category-icon{width:37px;height:37px}.starting{display:block;padding-top:30px;padding-bottom:28px}.starting h2{font-size:27px}.featured{margin-top:19px}.worksheet-strip{margin-inline:16px;margin-bottom:35px;padding:20px;gap:14px}.worksheet-strip>div{flex:1}.worksheet-strip>a{margin-left:0}.footer-inner{padding-inline:16px}.footer-top,.footer-bottom{display:block}.footer-top>span{display:block;margin-top:4px}.footer-bottom>span{display:block;margin-top:13px}.footer-bottom a{display:block;line-height:1.8;font-size:12px}.article-wrap{padding-inline:16px;padding-bottom:45px}article h1{font-size:34px}article h2{font-size:25px}article p{font-size:17px}.article-intro p:first-child{font-size:18px}.header-search-row{padding-inline:16px}.category-title h1{font-size:37px}.article-row h2{font-size:20px}.process{gap:8px;font-size:11px;padding:17px 10px}.toc{display:none}.breadcrumbs{font-size:11px}.category-page{padding-bottom:45px}.feedback{gap:13px}.results{max-height:320px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}@media print{.site-header,.article-sidebar,.toc,footer,.feedback,.related{display:none}.article-layout{display:block}.article-wrap{padding:0}body{color:#000;background:#fff}.breadcrumbs{display:none}article{max-width:none}}
/* PWA knowledge base refinements */
.brand-mark{display:flex;align-items:center;justify-content:center;width:40px;height:44px;border-radius:7px}.brand-mark svg{width:32px;height:32px}.hero{overflow:visible}.hero-decoration{pointer-events:none;right:0;top:0;width:100px;height:100%;overflow:hidden;transform:none}.hero-decoration span{width:300px;height:300px;left:0;top:40px;right:auto;bottom:auto}.hero-decoration span:nth-child(2){inset:auto;left:30px;top:70px;width:240px;height:240px}.hero-decoration span:nth-child(3){inset:auto;left:60px;top:100px;width:180px;height:180px}.hero-inner{z-index:2}.results{z-index:30}.article-row small{font-size:12px;color:var(--muted);display:block;margin-top:10px}.offline-bar{border-top:1px solid var(--line);padding-top:17px;margin-top:24px;display:flex;align-items:center;gap:16px;flex-wrap:wrap;font-size:12px;color:var(--muted)}.offline-bar button{background:var(--bg);border:1px solid var(--line);border-radius:5px;padding:9px 12px;color:var(--accent);font-size:12px;min-height:44px}.offline-bar a{min-height:44px;display:inline-flex;align-items:center}.offline-status{margin-right:auto}.update-notice{padding:12px 16px;margin:15px 0 0;border:1px solid var(--line);background:var(--soft);border-radius:5px;font-size:13px}.sources{border:1px solid var(--line);background:var(--surface);padding:22px;border-radius:7px;margin-top:35px}.sources h2{font-size:20px;margin:0 0 12px}.sources p,.sources li{font-size:14px;line-height:1.7}.sources ul{margin:0;padding-left:20px}.sources li{margin:8px 0}.process-figure{margin:26px 0}.process-figure .process{margin:0 0 8px}.process-figure figcaption{font-size:11px;color:var(--muted)}.table-wrap{overflow-x:auto;margin:24px 0;border:1px solid var(--line);border-radius:6px}table{width:100%;border-collapse:collapse;font-size:15px;line-height:1.6}caption{text-align:left;font-size:13px;color:var(--muted);padding:14px;background:var(--surface)}th,td{text-align:left;vertical-align:top;padding:14px;border-bottom:1px solid var(--line)}th{background:var(--soft);font-weight:600}tr:last-child td{border-bottom:0}.mobile-article-nav{display:none}article,article section{min-width:0}article a{overflow-wrap:anywhere}.category-card p{font-size:15px}.category-card h3{font-size:18px}.category-card{min-height:220px}.eyebrow{font-size:11px}.footer-bottom{font-size:12px}.hero h1{font-weight:550}.related a{min-height:48px}.toc a{padding-block:5px}.article-sidebar nav a{min-height:44px}.text-link{display:inline-flex;align-items:center;min-height:44px}.search-examples a{padding-block:5px}.search-examples{align-items:center}.breadcrumbs a{min-height:32px;display:inline-flex;align-items:center}.breadcrumbs>span{align-self:center}
@media(max-width:800px){.mobile-article-nav{display:block;margin-bottom:25px;border:1px solid var(--line);border-radius:6px;font-size:14px}.mobile-article-nav summary{padding:12px 15px;cursor:pointer;color:var(--accent)}.mobile-article-nav nav{display:grid;padding:0 10px 10px;gap:3px}.mobile-article-nav nav a{padding:10px;min-height:44px}.mobile-article-nav [aria-current]{background:var(--soft);border-radius:4px}.article-sidebar{display:none}.worksheet-strip>a{margin-left:0}.process{flex-wrap:wrap}}
@media(max-width:520px){.category-card h3{font-size:16px}.category-card p{font-size:14px}.category-card{min-height:220px}.brand-mark{width:34px;height:40px}.brand-mark svg{width:29px;height:29px}.hero h1{font-size:35px}.hero p{font-size:16px}.category-grid{gap:10px}.hero-decoration{width:45px;opacity:.3}.offline-bar{gap:8px 14px}.offline-status{width:100%}.sources{padding:17px}.table-wrap th,.table-wrap td{padding:10px;font-size:14px}.process{font-size:12px;gap:8px}.process span{max-width:26%;text-align:center}.feedback>span{width:100%}}