:root{color-scheme:light;--bg:#f7f9fc;--surface:#fff;--surface-soft:#eaf4fc;--ink:#172536;--muted:#5e6e81;--line:#dfe6ee;--brand:#1769aa;--brand-strong:#115586;--warn:#8c5b12;--warn-bg:#fff6df;--danger:#9e3834;--shadow:0 14px 40px #16283b0d;font-family:system-ui,"Segoe UI",Tahoma,Arial,sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-size:16px;line-height:1.75}body[data-theme="warm"]{--bg:#f0f2f4;--surface:#fff;--surface-soft:#e5e9ee;--ink:#202832;--muted:#606b75;--line:#d9dee4}body[data-theme="dark"]{color-scheme:dark;--bg:#141a24;--surface:#1c2532;--surface-soft:#203548;--ink:#eaf1f8;--muted:#b4c0cd;--line:#354252;--brand:#71c5f0;--brand-strong:#95d7fa;--warn:#f6d68f;--warn-bg:#30291a;--danger:#ff9d95}.container{width:min(1160px,calc(100% - 36px));margin-inline:auto}.skip-link{position:absolute;inset-inline-start:-999px;top:8px;background:var(--surface);padding:8px}.skip-link:focus{inset-inline-start:8px;z-index:10}.site-header{position:sticky;top:0;z-index:5;background:color-mix(in srgb,var(--bg) 95%,transparent);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}.header-inner{min-height:74px;display:flex;align-items:center;justify-content:space-between;gap:22px}.brand{display:inline-flex;align-items:center;gap:12px;color:var(--ink);text-decoration:none;font-weight:800;font-size:20px;white-space:nowrap}.brand small{display:block;color:var(--muted);font-size:12px;font-weight:500}.brand-mark{position:relative;display:block;width:34px;height:34px;border:2px solid var(--brand);border-radius:50%;transform:rotate(-35deg)}.brand-mark:before{content:"";position:absolute;width:39px;height:15px;border:1.5px solid var(--brand);border-radius:50%;top:8px;left:-5px}.brand-mark:after{content:"";position:absolute;width:8px;height:8px;border-radius:50%;background:var(--brand);right:1px;top:1px}.brand-mark i{position:absolute;width:10px;height:10px;border-radius:50%;background:var(--brand);top:10px;left:10px}.main-nav{display:flex;align-items:center;gap:16px;flex-wrap:wrap}.main-nav a{color:var(--muted);text-decoration:none;font-size:14px}.main-nav a:hover,.main-nav a[aria-current="page"]{color:var(--brand);text-decoration:underline;text-underline-offset:5px}.nav-tools{margin-inline-start:5px}.nav-controls{display:flex;align-items:center;gap:8px}.icon-button,.language-link{border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:9px;padding:6px 10px;font:inherit;font-size:13px;text-decoration:none;cursor:pointer}.hero{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:48px;align-items:center;padding:54px 0 30px}.eyebrow{color:var(--brand);font-size:13px;font-weight:750}.hero h1{font-size:clamp(32px,5vw,48px);line-height:1.3;letter-spacing:-.025em;margin:8px 0}.hero h1 span{color:var(--brand)}.hero p{font-size:17px;color:var(--muted);max-width:730px;margin:12px 0 20px}.orbit-art{height:210px;border-radius:28px;background:var(--surface-soft);display:grid;place-items:center;position:relative}.orbit-art .orbit-core{display:grid;place-items:center;width:92px;height:92px;border-radius:50%;background:var(--brand);color:white;font-size:23px;font-weight:800}.orbit-art:before,.orbit-art:after{content:"";position:absolute;width:190px;height:75px;border:2px solid color-mix(in srgb,var(--brand) 48%,transparent);border-radius:50%;transform:rotate(-33deg)}.orbit-art:after{transform:rotate(33deg);width:170px}.orbit-label{position:absolute;font-size:12px;color:var(--muted)}.orbit-label.one{top:18px;right:25px}.orbit-label.two{bottom:17px;left:22px}.search{display:flex;gap:10px;align-items:center;max-width:520px;background:var(--surface);border:1px solid var(--line);padding:10px 14px;border-radius:10px;color:var(--muted)}.search input{width:100%;border:0;outline:0;background:transparent;color:var(--ink);font:inherit;font-size:15px}.ad-slot{min-height:82px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;border:1px dashed var(--line);border-radius:8px;background:var(--surface);color:var(--muted);padding:12px;font-size:13px}.ad-slot small{font-size:12px}.ad-wide{margin:10px auto 28px}.section-head{display:flex;justify-content:space-between;align-items:end;gap:12px;margin:22px 0 10px}.section-head h2{font-size:23px;line-height:1.4;margin:2px 0}.section-head>a,.text-link{color:var(--brand);font-size:14px;text-decoration:none}.category-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:0 22px;border-top:1px solid var(--line)}.category-link{display:grid;grid-template-columns:36px 1fr;align-items:center;gap:0 10px;padding:13px 3px;border-bottom:1px solid var(--line);text-decoration:none;color:var(--ink)}.category-link b{grid-row:span 2;color:var(--brand);font-size:12px}.category-link strong{font-size:15px}.category-link small{color:var(--muted);font-size:13px}.home-layout,.article-layout{display:grid;grid-template-columns:minmax(0,1fr) minmax(190px,clamp(205px,24vw,255px));gap:28px;align-items:stretch;margin-top:28px}.feature{display:grid;grid-template-columns:1.1fr .9fr;gap:18px;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:13px;padding:19px;box-shadow:var(--shadow)}.feature h2{font-size:21px;line-height:1.5;margin:6px 0}.feature p{font-size:15px}.tag{font-size:12px;color:var(--brand);font-weight:750}.meta{font-size:13px;color:var(--muted)}.button{display:inline-flex;align-items:center;justify-content:center;border:0;border-radius:9px;background:var(--brand);color:#fff;padding:9px 15px;text-decoration:none;font:inherit;font-weight:700;font-size:14px}.button:hover{background:var(--brand-strong)}.image-slot{min-height:165px;background:var(--surface-soft);border:1px dashed var(--brand);border-radius:11px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:17px;color:var(--ink);font-size:14px}.image-slot small{color:var(--muted);font-size:12px;margin-top:7px}.topic-list{margin-top:22px}.topic-list a{display:grid;grid-template-columns:1fr 20px;gap:2px 8px;padding:11px 2px;border-bottom:1px solid var(--line);color:var(--ink);text-decoration:none}.topic-list a strong{font-size:14px}.topic-list a small{grid-column:1;color:var(--muted);font-size:12px}.topic-list a span{grid-column:2;grid-row:1/3;align-self:center;color:var(--brand)}.home-ad{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:10px;min-height:460px;text-align:center;padding:18px 14px}.rail-ad{flex:1 1 180px;min-height:180px}.rail{display:flex;flex-direction:column;justify-content:space-between;gap:18px;background:var(--surface);border:1px solid var(--line);border-radius:11px;padding:16px}.rail .toc strong{font-size:14px}.rail ol{padding-inline-start:22px;color:var(--muted);font-size:13px;line-height:2}.rail-note{font-size:12px;color:var(--muted)}.page-heading{padding:28px 0 8px}.breadcrumbs{font-size:13px;color:var(--muted);padding-top:18px}.page-heading h1,.article h1{font-size:clamp(28px,4vw,36px);line-height:1.4;margin:5px 0 10px}.page-lead,.article .lead{font-size:17px;line-height:1.9;color:var(--muted);max-width:850px}.prose{max-width:900px}.prose h2{font-size:23px;line-height:1.5;margin:28px 0 7px}.prose h3{font-size:18px;margin:20px 0 5px}.prose p,.prose li{font-size:16px;line-height:1.95}.prose li+li{margin-top:5px}.callout{border-inline-start:4px solid #d49a35;background:var(--warn-bg);padding:12px 16px;margin:18px 0;border-radius:7px}.callout.danger{border-color:var(--danger)}.callout p{margin:5px 0 0}.step{margin:28px 0 34px}.step-heading{display:flex;align-items:center;gap:12px;margin-bottom:8px}.step-number{flex:none;width:38px;height:38px;display:grid;place-items:center;border-radius:50%;background:var(--brand);color:#fff;font-weight:800}.step-heading h2{font-size:22px;line-height:1.5;margin:0}.diagram{margin:16px 0;background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:16px}.diagram figcaption{font-size:13px;color:var(--muted);margin-top:11px}.flow{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:9px}.flow span{background:var(--surface-soft);border:1px solid var(--line);border-radius:9px;padding:9px 11px;font-size:13px;text-align:center}.flow b{color:var(--brand);font-size:18px}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:12px}.info-table{width:100%;border-collapse:collapse}.info-table th,.info-table td{text-align:start;padding:10px;border-bottom:1px solid var(--line);vertical-align:top}.info-table th{font-size:14px}.info-table td{font-size:14px;color:var(--muted)}.image-request{margin:14px 0;padding:15px;background:var(--surface-soft);border:1px dashed var(--line);border-radius:9px;color:var(--muted);font-size:13px}.related-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 20px}.related-list a{padding:12px 2px;border-bottom:1px solid var(--line);color:var(--brand);text-decoration:none}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}.field{display:grid;gap:5px}.field.full{grid-column:1/-1}.field label{font-weight:650;font-size:14px}.field input,.field textarea,.field select{width:100%;border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:8px;padding:10px 12px;font:inherit}.field textarea{min-height:150px;resize:vertical}.muted{color:var(--muted)}.notice{padding:12px 14px;background:var(--surface-soft);border-radius:8px;font-size:14px}.tool-list,.path-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.plain-item{padding:16px 0;border-bottom:1px solid var(--line)}.plain-item h2{font-size:18px;margin:0 0 5px}.plain-item p{color:var(--muted);margin:0 0 8px}.source-list{font-size:13px;overflow-wrap:anywhere}.site-footer{margin-top:50px;border-top:1px solid var(--line);padding:20px 0;color:var(--muted);font-size:13px;display:flex;justify-content:space-between;gap:12px}.site-footer a{color:inherit}.mobile-menu{display:none}
body[dir="ltr"]{direction:ltr}body[dir="ltr"] .hero,body[dir="ltr"] .home-layout,body[dir="ltr"] .article-layout{direction:ltr}body[dir="ltr"] .prose,body[dir="ltr"] .article{text-align:left}body[dir="ltr"] .callout{border-inline-start:0;border-left:4px solid #d49a35}body[dir="ltr"] .callout.danger{border-left-color:var(--danger)}
@media(max-width:850px){.main-nav{gap:10px}.main-nav a{font-size:13px}.hero{grid-template-columns:1fr;gap:20px}.orbit-art{display:none}.home-layout,.article-layout{grid-template-columns:1fr}.home-ad{min-height:160px}.rail{grid-row:1}.rail ol{display:grid;grid-template-columns:1fr 1fr;column-gap:10px}.rail-ad{min-height:100px;flex:auto}.category-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:590px){body{font-size:15px}.container{width:min(100% - 26px,1160px)}.header-inner{align-items:flex-start;flex-direction:column;padding:12px 0}.main-nav{width:100%;justify-content:flex-start;gap:8px 14px}.main-nav a{font-size:12px}.nav-controls{position:absolute;top:20px;left:13px}body[dir="ltr"] .nav-controls{left:auto;right:13px}.hero{padding-top:30px}.hero h1{font-size:34px}.hero p{font-size:16px}.category-grid{grid-template-columns:1fr}.feature{grid-template-columns:1fr}.related-list,.tool-list,.path-list,.two-col,.form-grid{grid-template-columns:1fr}.site-footer{flex-direction:column}.page-heading h1,.article h1{font-size:29px}.prose p,.prose li{font-size:15px}}

/* Selected logo concept 1: orbit and core point. */
.brand-mark{position:static;display:block;width:40px;height:40px;flex:none;border:0;border-radius:0;transform:none}

.encyclopedia-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.encyclopedia-card{display:grid;grid-template-columns:minmax(0,1fr);gap:13px;align-items:start;padding:19px;background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);min-width:0}
.category-index{display:grid;place-items:center;width:38px;height:38px;border-radius:10px;background:var(--surface-soft);color:var(--brand);font-size:12px;font-weight:800;font-variant-numeric:tabular-nums}
.category-kicker{color:var(--brand);font-size:11px;font-weight:750}
.encyclopedia-card h2{font-size:17px;line-height:1.5;margin:2px 0 5px}
.encyclopedia-card p{font-size:14px;line-height:1.8;color:var(--muted);margin:4px 0 9px}
.encyclopedia-card .text-link{font-weight:700}
.category-status{display:inline-block;padding:3px 8px;border:1px solid var(--line);border-radius:20px;color:var(--muted);font-size:11px}
.category-footnote{font-size:12px;color:var(--muted);margin:18px 0 4px}
@media(max-width:680px){.encyclopedia-grid{grid-template-columns:1fr}.encyclopedia-card{padding:16px}}
.tool-app{max-width:850px;margin:20px 0;padding:20px;background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow)}
.tool-app form{display:grid;gap:14px;grid-template-columns:repeat(2,minmax(0,1fr));align-items:end}
.tool-app label{display:grid;gap:5px;font-size:14px;font-weight:650}
.tool-app input,.tool-app select{width:100%;min-width:0;border:1px solid var(--line);background:var(--bg);color:var(--ink);border-radius:8px;padding:9px 11px;font:inherit}
.tool-app fieldset{display:flex;flex-wrap:wrap;gap:10px;border:1px solid var(--line);border-radius:8px;padding:10px}
.tool-app fieldset label{display:flex;align-items:center;gap:5px;font-size:13px;font-weight:500}
.tool-app fieldset input{width:auto}
.tool-app form>button{justify-self:start}
.tool-app [data-tool-output]{margin-top:18px;overflow-wrap:anywhere}
.generated-password{display:block;padding:12px;background:var(--surface-soft);border-radius:8px;font:600 18px/1.6 ui-monospace,Consolas,monospace;user-select:all;overflow-wrap:anywhere}
@media(max-width:590px){.tool-app{padding:15px}.tool-app form{grid-template-columns:1fr}}


/* Glossary search and topic filters */
.glossary-controls{display:grid;grid-template-columns:minmax(0,2fr) minmax(180px,1fr) auto;gap:12px;align-items:end;margin:1rem 0 1.25rem}
.glossary-controls label{display:grid;gap:6px;font-size:.92rem;font-weight:650}
.glossary-controls input,.glossary-controls select{width:100%;min-height:44px;padding:.65rem .8rem;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--text);font:inherit}
.glossary-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.glossary-card h2 small{display:block;margin-top:.25rem;color:var(--muted);font-size:.88rem;font-weight:500}
.glossary-example{margin-top:.75rem;padding:.7rem .85rem;border-radius:9px;background:var(--surface-soft);font-size:.94rem}
.glossary-empty{padding:1rem;border:1px dashed var(--line);border-radius:10px;color:var(--muted)}
@media(max-width:680px){.glossary-controls,.glossary-list{grid-template-columns:1fr}.glossary-controls button{justify-self:start}}