:root{
  --paper:#f7f4ed;--paper-2:#f0ece3;--white:#fff;--ink:#172132;--ink-2:#273247;
  --slate:#4f5b70;--muted:#6f7888;--rust:#b94f3d;--rust-dark:#933a2d;
  --gold:#d39420;--blue:#168fb0;--blue-soft:#dbeff3;--line:#d9d3c8;--dark:#111a29;
  --max:1240px;--radius:22px;--shadow:0 28px 70px rgba(24,33,49,.14);
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.58;-webkit-font-smoothing:antialiased}img{display:block;max-width:100%;height:auto}a{color:inherit}.container{width:min(calc(100% - 48px),var(--max));margin-inline:auto}.narrow{max-width:840px}.sr-only{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip:rect(0,0,0,0)!important;white-space:nowrap!important;border:0!important}.skip-link{position:fixed;left:16px;top:-80px;background:var(--dark);color:#fff;padding:12px 16px;z-index:1000;border-radius:10px}.skip-link:focus{top:16px}
.site-header{position:sticky;top:0;z-index:50;background:rgba(247,244,237,.92);backdrop-filter:blur(14px);border-bottom:1px solid rgba(217,211,200,.8)}.header-inner{height:78px;display:flex;align-items:center;justify-content:space-between;gap:30px}.wordmark{text-decoration:none;font-weight:850;font-size:21px;letter-spacing:-.04em}.wordmark span{color:var(--ink)}.wordmark strong{color:var(--rust);margin-left:5px}.site-nav{display:flex;align-items:center;gap:25px}.site-nav a{text-decoration:none;font-weight:720;font-size:14px;color:#344055}.site-nav a:hover,.site-nav a[aria-current="page"]{color:var(--rust)}.nav-cta{border:1px solid var(--ink)!important;padding:10px 15px;border-radius:999px;color:var(--ink)!important}.nav-cta:hover{background:var(--ink);color:#fff!important}.nav-toggle{display:none;width:44px;height:44px;border:0;background:transparent;position:relative}.nav-toggle span:not(.sr-only){position:absolute;left:10px;width:24px;height:2px;background:var(--ink);transition:.2s}.nav-toggle span:nth-of-type(1){top:17px}.nav-toggle span:nth-of-type(2){top:25px}
.section{padding:112px 0}.section-sm{padding:78px 0}.eyebrow{font-size:12px;letter-spacing:.34em;text-transform:uppercase;font-weight:850;color:var(--rust);margin:0 0 22px}.eyebrow.dark{color:var(--gold)}.display{font-size:clamp(54px,7vw,96px);line-height:.98;letter-spacing:-.06em;margin:0}.section-title{font-size:clamp(42px,5.5vw,72px);line-height:1.04;letter-spacing:-.055em;margin:0 0 28px}.subhead{font-size:clamp(20px,2.2vw,28px);line-height:1.42;color:var(--slate)}.body-lg{font-size:20px;color:var(--slate)}.chapter-tag{display:inline-flex;align-items:center;gap:9px;font-size:11px;letter-spacing:.16em;text-transform:uppercase;font-weight:820;color:var(--muted)}.chapter-tag:before{content:"";width:28px;height:2px;background:var(--gold)}
.button-row{display:flex;gap:13px;flex-wrap:wrap;margin-top:36px}.button{display:inline-flex;align-items:center;justify-content:center;gap:10px;text-decoration:none;padding:14px 20px;border-radius:999px;font-size:14px;font-weight:820;border:1px solid transparent;transition:.2s ease}.button-primary{background:var(--ink);color:#fff}.button-primary:hover{background:var(--rust)}.button-secondary{border-color:#a9a59d;background:rgba(255,255,255,.45)}.button-secondary:hover{border-color:var(--rust);color:var(--rust)}.text-link{font-weight:820;text-decoration:none;border-bottom:1px solid currentColor;padding-bottom:3px}.text-link:hover{color:var(--rust)}
.hero{position:relative;overflow:hidden;padding:86px 0 92px;border-bottom:1px solid var(--line);min-height:760px;display:flex;align-items:center}.hero:after{content:"";position:absolute;right:-100px;top:0;width:700px;height:700px;background:url('/assets/img/trajectory-field.svg') center/contain no-repeat;opacity:.28;pointer-events:none}.hero-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(360px,.7fr);gap:84px;align-items:center;position:relative;z-index:2}.hero h1 em{font-style:normal;color:var(--rust)}.hero-lede{max-width:760px;font-size:21px;color:var(--slate);margin:30px 0 0}.hero-lede strong{color:var(--ink)}.hero-note{margin-top:28px;display:flex;gap:12px;align-items:center;color:var(--muted);font-size:13px}.hero-note i{width:8px;height:8px;border-radius:50%;background:var(--blue);box-shadow:0 0 0 7px rgba(22,143,176,.12)}.book-photo-wrap{position:relative;justify-self:end;max-width:455px}.book-photo{display:block;width:100%;height:auto;aspect-ratio:auto;object-fit:contain;border-radius:24px;box-shadow:var(--shadow);transform:rotate(1.2deg);border:1px solid rgba(23,33,50,.08)}.book-badge{position:absolute;left:-42px;bottom:46px;background:var(--dark);color:#fff;border-radius:18px;padding:16px 20px;box-shadow:0 18px 42px rgba(17,26,41,.24)}.book-badge strong{display:block;font-size:14px}.book-badge span{display:block;font-size:11px;color:#c8d0dc;text-transform:uppercase;letter-spacing:.15em;margin-top:4px}.premise-strip{background:var(--dark);color:#fff;padding:31px 0}.premise-strip p{margin:0;text-align:center;font-size:clamp(20px,2.3vw,31px);font-weight:720;letter-spacing:-.02em}.premise-strip strong{color:#f0b94c}
.split-heading{display:grid;grid-template-columns:.85fr 1.15fr;gap:100px;align-items:start;margin-bottom:58px}.split-heading .body-lg{margin-top:8px}.diagnosis-list{border-top:1px solid var(--line)}.diagnosis-item{display:grid;grid-template-columns:135px .72fr 1.2fr;gap:52px;padding:44px 0;border-bottom:1px solid var(--line);align-items:start}.diagnosis-number{font-size:56px;line-height:1;font-weight:880;color:var(--rust)}.diagnosis-item h3{font-size:30px;line-height:1.15;margin:4px 0 0;letter-spacing:-.035em}.diagnosis-item p{font-size:19px;color:var(--slate);margin:4px 0 0}.diagnosis-item:hover{background:linear-gradient(90deg,transparent,rgba(255,255,255,.55),transparent)}
.quote-panel{background:var(--dark);color:#fff;position:relative;overflow:hidden}.quote-panel:before{content:"";position:absolute;inset:-15% -10% -15% 45%;background:url('/assets/img/trajectory-field.svg') center/contain no-repeat;opacity:.18}.quote-grid{display:grid;grid-template-columns:1fr 1fr;gap:100px;position:relative}.big-quote{font-size:clamp(40px,5.5vw,76px);line-height:1.04;letter-spacing:-.05em;font-weight:820;margin:0}.big-quote span{color:#f0b94c}.side-quote{align-self:end;padding-bottom:10px}.side-quote p{font-family:Georgia,serif;font-style:italic;font-size:28px;line-height:1.5;color:#d6dce5;margin:0}.side-quote cite{display:block;margin-top:18px;font-style:normal;color:#8fcada;font-size:12px;letter-spacing:.16em;text-transform:uppercase;font-weight:800}
.progression{display:grid;grid-template-columns:repeat(4,1fr);gap:0;margin-top:56px;border:1px solid var(--line);border-radius:24px;overflow:hidden;background:var(--white)}.progress-step{padding:34px 28px 38px;border-right:1px solid var(--line);position:relative;min-height:310px}.progress-step:last-child{border-right:0;background:var(--rust);color:#fff}.progress-step:not(:last-child):after{content:"→";position:absolute;right:-14px;top:45px;z-index:2;width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:var(--paper);color:var(--rust);font-weight:900}.progress-step .num{font-size:12px;letter-spacing:.14em;color:#8c95a3;font-weight:850}.progress-step:last-child .num{color:#f4cbc4}.progress-step h3{font-size:25px;margin:38px 0 8px;letter-spacing:-.035em}.progress-step .question{font-size:14px;color:var(--rust);font-weight:850;margin:0 0 22px}.progress-step:last-child .question{color:#fff}.progress-step p:last-child{color:var(--slate);font-size:16px;margin:0}.progress-step:last-child p:last-child{color:#fff}
.definition-layout{display:grid;grid-template-columns:1.05fr .95fr;gap:90px;align-items:start}.definition-quote{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:48px;box-shadow:0 16px 42px rgba(23,33,50,.06)}.definition-quote blockquote{margin:0;font-size:clamp(31px,3.8vw,52px);line-height:1.14;letter-spacing:-.04em;font-weight:780}.definition-quote blockquote em{font-style:normal;color:var(--rust)}.definition-quote cite{display:block;margin-top:28px;color:var(--muted);font-style:normal;font-size:13px}.primitive-list{display:grid;gap:18px}.primitive{border-top:1px solid var(--line);padding:27px 0;display:grid;grid-template-columns:62px 1fr;gap:18px}.primitive:first-child{border-top:0;padding-top:0}.primitive .icon{width:44px;height:44px;border-radius:50%;display:grid;place-items:center;background:var(--blue-soft);color:var(--blue);font-weight:900}.primitive h3{margin:0 0 8px;font-size:23px}.primitive p{margin:0;color:var(--slate)}.connection-callout{margin-top:58px;border-left:5px solid var(--gold);padding:24px 28px;background:#efe9db;font-size:25px;font-weight:760;letter-spacing:-.025em}
.absent-section{padding:86px 0;background:var(--rust);color:#fff}.absent-grid{display:grid;grid-template-columns:.8fr 1.2fr;gap:90px;align-items:center}.absent-grid .chapter-tag{color:#f8cfc8}.absent-grid .chapter-tag:before{background:#fff}.absent-line{font-size:clamp(44px,6.2vw,86px);line-height:1.02;letter-spacing:-.06em;font-weight:850;margin:0}.absent-line span{color:#ffe1a1}.absent-copy{font-size:20px;color:#fff;margin:18px 0 0;max-width:600px}
.agent-grid{display:grid;grid-template-columns:1fr 1fr;gap:100px;align-items:center}.agent-contrast{border:1px solid var(--line);border-radius:24px;overflow:hidden;background:var(--white)}.agent-row{display:grid;grid-template-columns:150px 1fr;gap:26px;padding:32px;border-bottom:1px solid var(--line)}.agent-row:last-child{border-bottom:0}.agent-row strong{font-size:14px;text-transform:uppercase;letter-spacing:.16em;color:var(--rust)}.agent-row p{margin:0;font-size:20px;color:var(--ink-2)}.agent-quote{margin-top:34px;padding:28px 0 0;border-top:3px solid var(--blue);font-size:34px;font-weight:820;letter-spacing:-.04em}.agent-quote span{color:var(--rust)}
.leadership{background:#f3efe8}.pivot-table{border:1px solid #d2cbc0;border-radius:18px;overflow:hidden;background:#ece7df;margin-top:48px}.pivot-head,.pivot-row{display:grid;grid-template-columns:1fr 1fr}.pivot-head>div{padding:24px 30px;color:#fff;text-transform:uppercase;letter-spacing:.24em;font-size:12px;font-weight:850}.pivot-head>div:first-child{background:#505b72}.pivot-head>div:last-child{background:var(--rust)}.pivot-row>div{padding:27px 32px;border-bottom:1px solid #d2cbc0;font-size:20px;color:var(--slate)}.pivot-row>div:first-child{border-right:1px solid #d2cbc0}.pivot-row>div:last-child{font-weight:800;color:var(--ink)}.pivot-row:last-child>div{border-bottom:0}.pivot-row:last-child>div:last-child{background:var(--rust);color:#fff;font-size:23px}.builders-line{text-align:center;color:var(--rust);font-size:30px;font-weight:820;font-style:italic;margin:36px 0 0}
.transition-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:50px}.transition-card{background:#eeeae4;border:1px solid #ded7cd;border-radius:15px;overflow:visible;position:relative;min-height:350px}.transition-card:before{content:"";display:block;height:14px;background:var(--rust);border-radius:14px 14px 0 0}.transition-card:not(:last-child):after{content:"→";position:absolute;right:-24px;top:48%;z-index:5;color:var(--rust);font-size:22px;font-weight:900;width:30px;height:30px;border-radius:50%;background:var(--paper);display:grid;place-items:center}.transition-card .inner{padding:34px 29px}.transition-card .step{color:#919aa8;letter-spacing:.25em;font-size:16px;font-weight:850}.transition-card h3{color:var(--rust);font-size:27px;letter-spacing:.14em;text-transform:uppercase;margin:28px 0 28px}.transition-card p{color:var(--slate);margin:0}.transition-bottom{text-align:center;margin-top:34px;color:var(--rust);font-size:25px;font-style:italic;font-weight:820}
.book-section{background:var(--dark);color:#fff;position:relative;overflow:hidden}.book-section:after{content:"";position:absolute;right:-190px;bottom:-220px;width:650px;height:650px;background:url('/assets/img/trajectory-field.svg') center/contain no-repeat;opacity:.18}.book-grid{display:grid;grid-template-columns:365px 1fr;gap:90px;align-items:center;position:relative;z-index:2}.flat-cover-frame{width:100%;max-width:365px;justify-self:center}.flat-cover{display:block;width:100%;max-width:none;height:auto!important;object-fit:contain;filter:drop-shadow(0 28px 34px rgba(0,0,0,.34));transform:rotate(-1.3deg)}.book-section h2{color:#fff}.book-section .body-lg{color:#c9d0db}.part-list{display:grid;gap:14px;margin:32px 0}.part{display:grid;grid-template-columns:62px 1fr;gap:16px;padding:17px 0;border-top:1px solid rgba(255,255,255,.14)}.part:last-child{border-bottom:1px solid rgba(255,255,255,.14)}.part span{color:#f0b94c;font-size:12px;font-weight:850;letter-spacing:.13em}.part strong{font-size:18px}.endorsements{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:40px}.endorsement{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.12);border-radius:16px;padding:25px}.endorsement p{font-family:Georgia,serif;font-style:italic;color:#e6eaf0;margin:0 0 18px}.endorsement strong{font-size:13px}.endorsement span{font-size:12px;color:#9ca8b6;display:block}
.final-cta{text-align:center}.final-cta blockquote{max-width:980px;margin:0 auto;font-size:clamp(39px,5.8vw,78px);line-height:1.06;letter-spacing:-.055em;font-weight:850}.final-cta blockquote span{color:var(--rust)}.final-cta p{max-width:700px;margin:28px auto 0;color:var(--slate);font-size:19px}.signup{margin-top:54px;display:flex;justify-content:center}.signup-form{width:min(100%,650px)}.signup-form label{display:block;text-align:left;font-weight:780;font-size:13px;margin:0 0 8px}.form-row{display:flex;gap:10px}.signup-form input,.contact-card input,.contact-card textarea,.contact-card select{width:100%;border:1px solid #bab4aa;background:#fff;padding:15px 17px;border-radius:12px;font:inherit;color:var(--ink)}.signup-form input:focus,.contact-card input:focus,.contact-card textarea:focus,.contact-card select:focus{outline:3px solid rgba(22,143,176,.18);border-color:var(--blue)}.form-note{font-size:12px!important;color:var(--muted)!important;text-align:left;margin:9px 0 0!important}
.site-footer{background:#0a111d;color:#fff;padding:68px 0}.footer-grid{display:grid;grid-template-columns:1.1fr .8fr .8fr;gap:65px}.footer-grid p{color:#9ba6b5;max-width:430px}.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:11px 22px}.footer-links a,.footer-meta a{color:#c6ced9;text-decoration:none;font-size:14px}.footer-links a:hover,.footer-meta a:hover{color:#f0b94c}.footer-meta{text-align:right}.footer-meta p{margin:0 0 8px}
.page-hero{padding:100px 0 80px;border-bottom:1px solid var(--line);position:relative;overflow:hidden}.page-hero:after{content:"";position:absolute;right:-120px;top:-120px;width:550px;height:550px;background:url('/assets/img/trajectory-field.svg') center/contain no-repeat;opacity:.16}.page-hero .container{position:relative;z-index:1}.page-hero h1{font-size:clamp(50px,7vw,88px);line-height:1;letter-spacing:-.06em;margin:0 0 26px;max-width:1050px}.page-lede{font-size:22px;color:var(--slate);max-width:850px}.article-layout{display:grid;grid-template-columns:230px minmax(0,790px);gap:100px;justify-content:center}.article-aside{position:sticky;top:110px;align-self:start;border-left:2px solid var(--line);padding-left:19px;display:grid;gap:10px}.article-aside strong{text-transform:uppercase;letter-spacing:.15em;font-size:11px;margin-bottom:6px}.article-aside a{text-decoration:none;color:var(--muted);font-size:14px}.article-aside a:hover{color:var(--rust)}.prose{font-size:18px}.prose h2{font-size:clamp(34px,4.4vw,54px);line-height:1.08;letter-spacing:-.045em;margin:76px 0 22px}.prose h2:first-child{margin-top:0}.prose h3{font-size:25px;letter-spacing:-.03em;margin-top:38px}.prose p,.prose li{color:#3e495c}.prose blockquote{margin:40px 0;padding:30px;border-left:5px solid var(--rust);background:#efeae2;font-size:28px;font-weight:750;letter-spacing:-.03em}.prose .definition{background:var(--dark);color:#fff;padding:34px;border-radius:20px}.prose .definition p{color:#fff;font-size:25px;margin:10px 0 0}.prose .definition span{color:#8fcada;text-transform:uppercase;letter-spacing:.15em;font-size:11px;font-weight:850}.cards-2,.cards-3,.cards-4{display:grid;gap:18px}.cards-2{grid-template-columns:repeat(2,1fr)}.cards-3{grid-template-columns:repeat(3,1fr)}.cards-4{grid-template-columns:repeat(4,1fr)}.info-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:28px}.info-card h3{margin:0 0 10px}.info-card p{margin:0;color:var(--slate)}.metric{font-size:12px;text-transform:uppercase;letter-spacing:.15em;color:var(--rust);font-weight:850}.glossary-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.glossary-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:28px;min-height:250px}.glossary-card h2{font-size:27px;letter-spacing:-.035em;margin:0 0 12px}.glossary-card p{color:var(--slate);font-size:16px}.book-page-grid{display:grid;grid-template-columns:390px 1fr;gap:90px;align-items:center}.book-page-cover{width:100%;max-width:390px;justify-self:center;filter:drop-shadow(0 28px 38px rgba(23,33,50,.2))}.book-page-cover img{display:block;width:100%;max-width:none;height:auto!important;object-fit:contain}.reading-paths{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}.reading-path{border:1px solid var(--line);background:#fff;border-radius:18px;padding:28px}.reading-path h3{margin-top:0}.reading-path p{color:var(--slate)}.contact-layout{display:grid;grid-template-columns:1fr 420px;gap:90px}.contact-card{background:#fff;border:1px solid var(--line);border-radius:20px;padding:32px}.contact-card form{display:grid;gap:9px}.contact-card label{font-size:13px;font-weight:800;margin-top:7px}.author-bio p{font-size:19px;color:#3e495c}.download-box{background:#efeae2;border:1px solid var(--line);border-radius:20px;padding:34px;margin-top:36px}
@media(max-width:1020px){.site-nav{position:fixed;top:78px;left:0;right:0;background:var(--paper);border-bottom:1px solid var(--line);padding:20px 24px;display:none;flex-direction:column;align-items:stretch;gap:3px}.site-nav.open{display:flex}.site-nav a{padding:10px}.nav-toggle{display:block}.hero-grid{grid-template-columns:1fr 370px;gap:44px}.hero .display{font-size:62px}.split-heading,.definition-layout,.agent-grid,.book-grid,.contact-layout{gap:54px}.diagnosis-item{grid-template-columns:95px .85fr 1.1fr;gap:30px}.transition-cards{grid-template-columns:repeat(2,1fr)}.transition-card:nth-child(2):after{display:none}.glossary-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:780px){.container{width:min(calc(100% - 30px),var(--max))}.section{padding:82px 0}.section-sm{padding:58px 0}.header-inner{height:70px}.site-nav{top:70px}.hero{padding:64px 0 72px}.hero-grid,.split-heading,.quote-grid,.definition-layout,.absent-grid,.agent-grid,.book-grid,.book-page-grid,.contact-layout{grid-template-columns:1fr}.hero-grid{gap:48px}.hero .display{font-size:clamp(48px,13vw,64px)}.hero-lede{font-size:18px}.book-photo-wrap{justify-self:center;max-width:390px}.book-badge{left:14px;bottom:18px}.split-heading{gap:22px}.diagnosis-item{grid-template-columns:74px 1fr;gap:12px 22px;padding:34px 0}.diagnosis-number{font-size:40px}.diagnosis-item p{grid-column:2}.quote-grid{gap:55px}.progression{grid-template-columns:1fr}.progress-step{border-right:0;border-bottom:1px solid var(--line);min-height:0}.progress-step:not(:last-child):after{content:"↓";right:auto;left:30px;top:auto;bottom:-15px}.progress-step:last-child{border-bottom:0}.connection-callout{font-size:21px}.agent-row{grid-template-columns:1fr;gap:8px}.pivot-head>div,.pivot-row>div{padding:21px 17px}.pivot-head>div{letter-spacing:.12em}.pivot-row>div{font-size:16px}.builders-line{font-size:23px}.transition-cards{grid-template-columns:1fr}.transition-card:not(:last-child):after{content:"↓";right:50%;top:auto;bottom:-26px;transform:translateX(50%)}.book-grid{gap:48px}.flat-cover-frame{max-width:270px}.flat-cover{margin:auto}.endorsements,.reading-paths,.cards-2,.cards-3,.cards-4,.glossary-grid{grid-template-columns:1fr}.form-row{flex-direction:column}.footer-grid{grid-template-columns:1fr;gap:38px}.footer-meta{text-align:left}.article-layout{grid-template-columns:1fr}.article-aside{position:static;display:flex;flex-wrap:wrap;border-left:0;border-bottom:1px solid var(--line);padding:0 0 20px}.article-aside strong{width:100%}.page-hero{padding:75px 0 60px}.page-hero h1{font-size:52px}.book-page-cover{max-width:280px;margin:auto}.book-page-grid>div:first-child{order:2}.book-page-grid>div:last-child{order:1}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.button{transition:none}}

.section-muted{background:#f0ece3}.button-row-center{justify-content:center}.subhead-inverse{color:#fff}.button-light{background:#fff;color:#172132}.button-light:hover{background:#f0ece3;color:#172132}.button-inverse{border-color:#667185;color:#fff;background:transparent}.button-inverse:hover{border-color:#fff;color:#fff}.footer-word{color:#fff!important}.info-card-accent{border-top:6px solid #b94f3d}.isbn-line{margin-top:40px;color:#aeb8c5}.concept-link-row{margin-top:-76px;padding-bottom:90px;text-align:center}.concept-index-intro{max-width:820px;margin-bottom:42px}.breadcrumbs{margin:0 0 27px}.breadcrumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:8px;align-items:center;padding:0;margin:0;color:var(--muted);font-size:13px}.breadcrumbs li{display:flex;align-items:center}.breadcrumbs li+li:before{content:"/";margin-right:8px;color:#a5a09a}.breadcrumbs a{text-decoration:none}.breadcrumbs a:hover{color:var(--rust)}.article-meta{display:flex;flex-wrap:wrap;gap:10px 24px;margin-top:30px;color:var(--muted);font-size:13px}.article-meta span,.article-meta time{display:flex;align-items:center}.article-meta span+span:before,.article-meta time+span:before{content:"·";margin-right:24px;color:#aaa39a}.page-source-strip{border-bottom:1px solid var(--line);background:#efeae2;padding:16px 0;color:var(--slate);font-size:14px}.page-source-strip strong{color:var(--ink)}.page-source-strip a{font-weight:800;color:var(--rust)}.concept-hero .page-lede{max-width:920px}.concept-article .prose>section{scroll-margin-top:105px}.concept-article .definition{scroll-margin-top:105px}.concept-article dfn{font-style:normal}.source-note{margin:70px 0 20px;border:1px solid var(--line);border-radius:20px;background:#fff;padding:30px}.source-note strong{display:block;color:var(--rust);text-transform:uppercase;letter-spacing:.14em;font-size:12px}.source-note p{margin:12px 0 18px}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.related-card{display:block;text-decoration:none;border:1px solid var(--line);border-radius:18px;background:#fff;padding:24px;transition:.2s ease}.related-card:hover{transform:translateY(-2px);border-color:var(--rust);box-shadow:0 12px 30px rgba(23,33,50,.08)}.related-card span{display:block;text-transform:uppercase;letter-spacing:.13em;color:var(--rust);font-size:10px;font-weight:850}.related-card strong{display:block;font-size:21px;margin:8px 0}.related-card p{font-size:14px;margin:0;color:var(--slate)}.glossary-card-link{position:relative;display:flex;flex-direction:column}.glossary-card-link h2 a{text-decoration:none}.glossary-card-link h2 a:after{content:"";position:absolute;inset:0}.card-arrow{position:relative;z-index:1;margin-top:auto;padding-top:20px;text-decoration:none;color:var(--rust);font-size:13px;font-weight:850}.glossary-card-link:hover{border-color:var(--rust);box-shadow:0 13px 32px rgba(23,33,50,.07)}.formula-card{margin:36px 0 10px;border-radius:18px;background:var(--dark);color:#fff;padding:28px}.formula-card span{display:block;color:#8fcada;text-transform:uppercase;letter-spacing:.15em;font-size:11px;font-weight:850}.formula-card strong{display:block;margin-top:10px;font-size:clamp(22px,3vw,34px);letter-spacing:-.03em}.table-scroll{overflow-x:auto;margin:38px 0 12px;border:1px solid var(--line);border-radius:16px;background:#fff}.concept-table{border-collapse:collapse;width:100%;min-width:780px;font-size:14px}.concept-table caption{text-align:left;padding:20px 22px;font-size:18px;font-weight:850}.concept-table th,.concept-table td{text-align:left;vertical-align:top;padding:18px 20px;border-top:1px solid var(--line)}.concept-table thead th{background:#eee9e1;color:var(--ink);font-size:12px;text-transform:uppercase;letter-spacing:.1em}.concept-table tbody th{width:18%;color:var(--ink)}.concept-table code{white-space:normal;color:var(--rust-dark);font-size:12px}.site-nav{gap:20px}.footer-mark .footer-word{color:#fff}.contact-card textarea{resize:vertical;min-height:150px}
@media(max-width:1020px){.site-nav{gap:3px}.related-grid{grid-template-columns:1fr 1fr}}
@media(max-width:780px){.concept-link-row{margin-top:-52px;padding-bottom:65px}.article-meta{gap:8px 14px}.article-meta span+span:before,.article-meta time+span:before{margin-right:14px}.related-grid{grid-template-columns:1fr}.concept-table{font-size:13px}.page-source-strip{padding:14px 0}.breadcrumbs{margin-bottom:22px}}


/* v6: book-first concepts index */
.concepts-page-hero{padding:94px 0 86px;border-bottom:1px solid var(--line);position:relative;overflow:hidden}
.concepts-page-hero:after{content:"";position:absolute;right:-110px;top:-145px;width:610px;height:610px;background:url('/assets/img/trajectory-field.svg') center/contain no-repeat;opacity:.13;pointer-events:none}
.concepts-page-hero .container{position:relative;z-index:1}
.concepts-page-hero h1{font-size:clamp(58px,7.2vw,92px);line-height:.98;letter-spacing:-.062em;margin:0 0 28px;max-width:980px;text-align:left}
.concepts-page-hero .page-lede{max-width:900px;font-size:23px;line-height:1.55;text-align:left}
.concepts-progression-wrap{padding:0 0 42px}
.concepts-progression{display:grid;grid-template-columns:repeat(4,1fr);background:var(--dark);color:#fff;border-radius:0 0 22px 22px;overflow:hidden;box-shadow:0 22px 48px rgba(17,26,41,.12)}
.concepts-progression-item{padding:30px 27px;min-height:154px;border-right:1px solid rgba(255,255,255,.13)}
.concepts-progression-item:last-child{border-right:0;background:var(--rust)}
.concepts-progression-item span{display:block;font-size:11px;letter-spacing:.17em;text-transform:uppercase;color:#92cbd8;font-weight:850;margin-bottom:10px}
.concepts-progression-item:last-child span{color:#ffe1a1}
.concepts-progression-item strong{display:block;font-size:21px;letter-spacing:-.025em;margin-bottom:5px}
.concepts-progression-item p{margin:0;color:#d8dee8;font-size:15px;line-height:1.48}
.concepts-progression-item:last-child p{color:#fff}
.concepts-map{padding-top:76px}
.concept-group{display:grid;grid-template-columns:285px minmax(0,1fr);gap:62px;padding:64px 0;border-top:1px solid var(--line)}
.concept-group:first-child{border-top:0;padding-top:0}
.concept-group-head{align-self:start}
.concept-group-number{display:block;color:var(--rust);font-size:48px;line-height:1;font-weight:850;letter-spacing:-.05em;margin-bottom:26px}
.concept-group-head .eyebrow{margin-bottom:14px}
.concept-group-head h2{font-size:clamp(34px,3.8vw,50px);line-height:1.06;letter-spacing:-.05em;margin:0 0 18px}
.concept-group-head p:last-child{color:var(--slate);font-size:17px;margin:0}
.concept-card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
.concept-card-grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}
.concept-card{position:relative;display:flex;flex-direction:column;min-height:292px;padding:30px;background:#fff;border:1px solid var(--line);border-radius:18px;text-decoration:none;color:inherit;overflow:hidden;transition:transform .18s ease,border-color .18s ease,box-shadow .18s ease}
.concept-card:before{content:"";position:absolute;left:0;top:0;right:0;height:5px;background:var(--rust)}
.concept-card:hover{transform:translateY(-3px);border-color:var(--rust);box-shadow:0 16px 34px rgba(23,33,50,.08)}
.concept-card-label{display:block;color:var(--rust);font-size:10px;letter-spacing:.15em;text-transform:uppercase;font-weight:850;margin:8px 0 22px}
.concept-card h3{font-size:28px;line-height:1.08;letter-spacing:-.04em;margin:0 0 14px}
.concept-card p{color:var(--slate);font-size:15px;line-height:1.58;margin:0}
.concept-card .card-arrow{margin-top:auto;padding-top:23px}
.concepts-supporting{background:var(--paper-2);border-top:1px solid var(--line)}
.concepts-supporting-head{display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:end;margin-bottom:42px}
.concepts-supporting-head .section-title{margin-bottom:0}
.concepts-supporting-head p{color:var(--slate);font-size:19px;margin:0}
.concept-mini-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.concept-mini{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px;min-height:188px}
.concept-mini h3{font-size:22px;letter-spacing:-.035em;margin:0 0 10px}
.concept-mini p{font-size:15px;color:var(--slate);margin:0}
@media(max-width:1100px){
  .concept-group{grid-template-columns:240px minmax(0,1fr);gap:40px}
  .concept-card-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .concept-card-grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}
  .concept-mini-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:780px){
  .concepts-page-hero{padding:72px 0 62px}
  .concepts-page-hero:after{right:-210px;top:-80px;width:500px;height:500px;opacity:.09}
  .concepts-page-hero h1{font-size:clamp(48px,13vw,62px)}
  .concepts-page-hero .page-lede{font-size:19px}
  .concepts-progression-wrap{padding-bottom:22px}
  .concepts-progression{grid-template-columns:1fr 1fr;border-radius:0 0 18px 18px}
  .concepts-progression-item{min-height:145px;border-bottom:1px solid rgba(255,255,255,.13)}
  .concepts-progression-item:nth-child(2){border-right:0}
  .concepts-progression-item:nth-child(n+3){border-bottom:0}
  .concept-group{grid-template-columns:1fr;gap:30px;padding:54px 0}
  .concept-group-number{font-size:42px;margin-bottom:18px}
  .concept-card-grid,.concept-card-grid.two,.concept-mini-grid{grid-template-columns:1fr}
  .concept-card{min-height:255px}
  .concepts-supporting-head{grid-template-columns:1fr;gap:18px;margin-bottom:30px}
}
@media(max-width:430px){
  .concepts-progression{grid-template-columns:1fr}
  .concepts-progression-item{border-right:0;border-bottom:1px solid rgba(255,255,255,.13)!important;min-height:0}
  .concepts-progression-item:last-child{border-bottom:0!important}
}