:root{
  --paper:#f4f5f1;
  --paper-2:#e9ebe5;
  --ink:#101a2c;
  --ink-2:#27344a;
  --blue:#1745d1;
  --blue-2:#0f36ad;
  --line:rgba(16,26,44,.16);
  --white:#fff;
  --muted:#5a6578;
  --shadow:0 24px 64px rgba(16,26,44,.14);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--paper)}
body{margin:0;color:var(--ink);background:
  linear-gradient(rgba(16,26,44,.035) 1px,transparent 1px),
  linear-gradient(90deg,rgba(16,26,44,.035) 1px,transparent 1px),var(--paper);
  background-size:34px 34px;font-family:"Instrument Sans","Aptos",Arial,sans-serif;line-height:1.5}
a{color:inherit}
img{display:block;max-width:100%}

.lesson-skip{position:fixed;z-index:100;top:10px;left:10px;padding:10px 14px;background:var(--ink);color:#fff;transform:translateY(-150%)}
.lesson-skip:focus{transform:none}

.lesson-header{min-height:82px;padding:0 clamp(20px,4vw,68px);display:flex;align-items:center;justify-content:space-between;gap:28px;border-bottom:1px solid var(--line);background:rgba(244,245,241,.92);backdrop-filter:blur(14px);position:relative;z-index:4}
.lesson-brand{display:inline-flex;align-items:center;gap:12px;text-decoration:none;font-size:12px;font-weight:800;line-height:1.05;letter-spacing:.09em}
.lesson-brand i{width:28px;height:28px;border:7px solid var(--ink);border-radius:50%;box-shadow:inset 0 0 0 3px var(--paper)}
.lesson-brand small{display:block;margin-top:5px;color:var(--blue);font-size:9px;letter-spacing:.2em}
.lesson-header nav{display:flex;align-items:center;gap:28px;font-size:13px;font-weight:700}
.lesson-header nav a{text-decoration:none}
.lesson-header__cta{padding:11px 16px;background:var(--ink);color:#fff}

.lesson-shell{width:min(1220px,calc(100% - 40px));margin:0 auto}
.lesson-breadcrumb{display:flex;align-items:center;gap:9px;padding:24px 0 18px;color:var(--muted);font-size:12px}
.lesson-breadcrumb a{text-underline-offset:4px}

.lesson-hero{display:grid;grid-template-columns:minmax(0,.9fr) minmax(420px,1.1fr);min-height:570px;border:1px solid var(--ink);background:var(--white);box-shadow:var(--shadow)}
.lesson-hero__copy{padding:clamp(34px,5vw,72px);display:flex;flex-direction:column;align-items:flex-start;justify-content:center}
.lesson-kicker{display:block;color:var(--blue);font-size:11px;font-weight:800;letter-spacing:.16em;text-transform:uppercase}
.lesson-hero h1,.lesson-workbench h2,.lesson-summary h2,.lesson-routes h2,.lesson-related h2,.lesson-conversion h2{font-family:"Bricolage Grotesque","Arial Black",sans-serif;font-weight:760;letter-spacing:-.045em;line-height:.98}
.lesson-hero h1{margin:18px 0 22px;font-size:clamp(45px,5.6vw,78px)}
.lesson-hero__copy>p{max-width:650px;margin:0;color:var(--ink-2);font-size:clamp(16px,1.55vw,20px);line-height:1.62}
.lesson-facts{width:100%;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0;margin:34px 0 30px;border-top:1px solid var(--line)}
.lesson-facts div{padding:14px 10px 12px 0;border-bottom:1px solid var(--line)}
.lesson-facts dt{color:var(--muted);font-size:10px;font-weight:800;letter-spacing:.11em;text-transform:uppercase}
.lesson-facts dd{margin:4px 0 0;font-size:12px;font-weight:700}
.lesson-button{min-height:48px;padding:13px 18px;display:inline-flex;align-items:center;justify-content:center;gap:16px;border:1px solid var(--ink);text-decoration:none;font-size:12px;font-weight:800;letter-spacing:.03em;transition:.2s ease}
.lesson-button:hover{transform:translateY(-2px)}
.lesson-button:focus-visible,.lesson-header a:focus-visible,.lesson-poster:focus-visible,.lesson-card a:focus-visible{outline:3px solid #ffb400;outline-offset:3px}
.lesson-button--dark{background:var(--ink);color:#fff}
.lesson-button--light{background:#fff;color:var(--ink)}
.lesson-button--outline{border-color:rgba(255,255,255,.62);color:#fff}
.lesson-poster{position:relative;min-height:100%;overflow:hidden;background:var(--ink);color:#fff}
.lesson-poster:after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,transparent 45%,rgba(5,10,20,.8))}
.lesson-poster img{width:100%;height:100%;object-fit:cover;transition:transform .6s ease}
.lesson-poster:hover img{transform:scale(1.025)}
.lesson-play{position:absolute;z-index:2;left:50%;top:50%;width:82px;height:82px;margin:-41px;display:grid;place-items:center;border:1px solid rgba(255,255,255,.8);border-radius:50%;background:rgba(16,26,44,.76);font-size:24px;backdrop-filter:blur(8px)}
.lesson-poster small{position:absolute;z-index:2;left:28px;bottom:25px;font-size:10px;font-weight:800;letter-spacing:.15em}

.lesson-workbench{margin:72px 0;display:grid;grid-template-columns:.85fr 1.15fr;border-top:5px solid var(--blue);background:var(--ink);color:#fff}
.lesson-workbench>div{padding:clamp(32px,5vw,62px)}
.lesson-workbench h2{max-width:470px;margin:16px 0 0;font-size:clamp(34px,4.1vw,56px)}
.lesson-workbench ol{margin:0;padding:0;list-style:none;border-left:1px solid rgba(255,255,255,.17)}
.lesson-workbench li{display:grid;grid-template-columns:58px 1fr;gap:20px;padding:28px;border-bottom:1px solid rgba(255,255,255,.17)}
.lesson-workbench li:last-child{border-bottom:0}
.lesson-workbench li>span{color:#89a7ff;font-size:13px;font-weight:800}
.lesson-workbench b{font-size:17px}
.lesson-workbench p{margin:5px 0 0;color:#c7cfdd;font-size:14px}

.lesson-summary{max-width:880px;margin:90px auto;padding:0 30px;text-align:center}
.lesson-summary h2{margin:15px 0 22px;font-size:clamp(40px,5vw,64px)}
.lesson-summary p{color:var(--ink-2);font-size:18px;line-height:1.75}
.lesson-summary small{display:block;margin-top:20px;color:var(--muted);font-size:11px}

.lesson-routes,.lesson-related{margin:92px 0}
.lesson-routes>div:first-child,.lesson-section-head{display:flex;align-items:end;justify-content:space-between;gap:25px;margin-bottom:25px}
.lesson-routes h2,.lesson-related h2{margin:11px 0 0;font-size:clamp(35px,4vw,52px)}
.lesson-route-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.lesson-route-grid a{min-height:210px;padding:26px;display:flex;flex-direction:column;border:1px solid var(--line);background:#fff;text-decoration:none;transition:.2s ease}
.lesson-route-grid a:hover{border-color:var(--blue);transform:translateY(-3px);box-shadow:0 16px 30px rgba(16,26,44,.08)}
.lesson-route-grid small{color:var(--blue);font-size:9px;font-weight:800;letter-spacing:.14em}
.lesson-route-grid b{margin:30px 0 8px;font-family:"Bricolage Grotesque",sans-serif;font-size:25px;line-height:1}
.lesson-route-grid span{color:var(--muted);font-size:13px}
.lesson-route-grid i{margin-top:auto;align-self:flex-end;color:var(--blue);font-size:20px;font-style:normal}

.lesson-section-head>a{color:var(--blue);font-size:12px;font-weight:800;text-underline-offset:4px}
.lesson-card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.lesson-card{border:1px solid var(--line);background:#fff}
.lesson-card a{height:100%;padding-bottom:22px;display:block;text-decoration:none}
.lesson-card img{width:100%;aspect-ratio:16/9;object-fit:cover;background:var(--paper-2)}
.lesson-card span{display:block;margin:17px 20px 0;color:var(--blue);font-size:9px;font-weight:800;letter-spacing:.14em;text-transform:uppercase}
.lesson-card h3{margin:8px 20px 22px;font-family:"Bricolage Grotesque",sans-serif;font-size:21px;line-height:1.12}
.lesson-card i{margin:0 20px;color:var(--blue);font-size:12px;font-weight:800;font-style:normal}

.lesson-conversion{margin:96px 0 70px;padding:clamp(42px,6vw,82px);background:var(--blue);color:#fff;text-align:center}
.lesson-conversion .lesson-kicker{color:#b9c9ff}
.lesson-conversion h2{max-width:870px;margin:17px auto 20px;font-size:clamp(42px,5.8vw,74px)}
.lesson-conversion>p{max-width:700px;margin:0 auto;color:#e1e8ff;font-size:17px}
.lesson-conversion>div{display:flex;justify-content:center;gap:10px;margin-top:34px;flex-wrap:wrap}

.lesson-footer{padding:34px clamp(20px,4vw,68px);display:flex;justify-content:space-between;gap:20px;border-top:1px solid var(--line);background:var(--paper-2);font-size:11px}
.lesson-footer b,.lesson-footer span{display:block}
.lesson-footer span{margin-top:4px;color:var(--muted)}
.lesson-footer nav{display:flex;gap:22px}

.lesson-problem{min-height:100vh;display:grid;place-items:center;padding:25px;text-align:center}
.lesson-problem>.lesson-brand{position:absolute;top:28px;left:28px}
.lesson-problem section{max-width:620px;padding:50px;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow)}
.lesson-problem section>span{color:var(--blue);font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.14em}
.lesson-problem h1{margin:16px 0;font-family:"Bricolage Grotesque",sans-serif;font-size:clamp(38px,6vw,64px);line-height:1}
.lesson-problem p{margin:0 0 30px;color:var(--muted)}

.route-hero{min-height:480px;padding:clamp(36px,6vw,78px);display:grid;grid-template-columns:minmax(0,1.2fr) minmax(330px,.8fr);align-items:end;gap:clamp(36px,7vw,100px);border:1px solid var(--ink);background:#fff;box-shadow:var(--shadow)}
.route-hero h1{max-width:760px;margin:18px 0 22px;font-family:"Bricolage Grotesque","Arial Black",sans-serif;font-size:clamp(56px,8vw,104px);font-weight:780;letter-spacing:-.06em;line-height:.86}
.route-hero>div>p{max-width:680px;margin:0;color:var(--ink-2);font-size:clamp(17px,1.7vw,21px)}
.route-source{display:block;max-width:680px;margin-top:22px;color:var(--muted);font-size:10px;line-height:1.5}
.route-hero aside{padding:26px;border-top:5px solid var(--blue);background:var(--paper-2)}
.route-hero aside small{color:var(--blue);font-size:10px;font-weight:800;letter-spacing:.13em}
.route-hero aside b{display:block;margin:15px 0 8px;font-family:"Bricolage Grotesque",sans-serif;font-size:24px;line-height:1.08}
.route-hero aside p{margin:0 0 23px;color:var(--muted);font-size:13px}
.route-catalog{margin:90px 0}
.route-catalog .lesson-section-head>span{color:var(--muted);font-size:12px;font-weight:700}
.route-list{margin:0;padding:0;list-style:none;border-top:1px solid var(--ink)}
.route-list li{border-bottom:1px solid var(--line)}
.route-list a{padding:18px 0;display:grid;grid-template-columns:52px 180px 1fr;align-items:center;gap:24px;text-decoration:none;transition:.18s ease}
.route-list a:hover{padding-left:10px;background:rgba(255,255,255,.7)}
.route-list__number{color:var(--blue);font-size:12px;font-weight:800}
.route-list img{width:180px;aspect-ratio:16/9;object-fit:cover;background:var(--paper-2)}
.route-list__copy small{display:block;color:var(--blue);font-size:9px;font-style:normal;font-weight:800;letter-spacing:.12em;text-transform:uppercase}
.route-list__copy b{display:block;margin:7px 0;font-family:"Bricolage Grotesque",sans-serif;font-size:clamp(20px,2.2vw,29px);line-height:1.05}
.route-list__copy em{color:var(--muted);font-size:11px;font-style:normal;font-weight:700}
.route-empty{margin:90px 0;padding:60px;border:1px solid var(--line);background:#fff;text-align:center}
.route-empty h2{font-family:"Bricolage Grotesque",sans-serif;font-size:45px;line-height:1}
.route-empty p{color:var(--muted)}
.route-other{margin:80px 0;display:grid;grid-template-columns:150px repeat(2,1fr);border-top:1px solid var(--ink);border-bottom:1px solid var(--ink)}
.route-other>span{padding:24px 10px 24px 0;color:var(--blue);font-size:10px;font-weight:800;letter-spacing:.14em}
.route-other a{position:relative;padding:24px;border-left:1px solid var(--line);text-decoration:none}
.route-other b,.route-other small{display:block}
.route-other b{font-family:"Bricolage Grotesque",sans-serif;font-size:23px}
.route-other small{max-width:360px;margin-top:4px;color:var(--muted);font-size:11px}
.route-other i{position:absolute;right:18px;top:18px;color:var(--blue);font-style:normal}

@media (max-width:900px){
  .lesson-header nav a:not(.lesson-header__cta){display:none}
  .lesson-hero{grid-template-columns:1fr}
  .lesson-hero__copy{order:2}
  .lesson-poster{min-height:360px;order:1}
  .lesson-workbench{grid-template-columns:1fr}
  .lesson-workbench ol{border-left:0;border-top:1px solid rgba(255,255,255,.17)}
  .lesson-route-grid,.lesson-card-grid{grid-template-columns:repeat(2,1fr)}
  .route-hero{grid-template-columns:1fr}
}

@media (max-width:620px){
  .lesson-header{min-height:70px;padding:0 16px}
  .lesson-brand{font-size:10px}
  .lesson-brand i{width:24px;height:24px;border-width:6px}
  .lesson-header__cta{padding:10px 12px;font-size:11px}
  .lesson-shell{width:min(100% - 24px,1220px)}
  .lesson-breadcrumb{padding:15px 2px;font-size:11px}
  .lesson-hero{min-height:0}
  .lesson-hero__copy{padding:30px 22px}
  .lesson-hero h1{font-size:clamp(39px,13vw,55px)}
  .lesson-hero__copy>p{font-size:15px}
  .lesson-poster{min-height:230px}
  .lesson-play{width:62px;height:62px;margin:-31px;font-size:18px}
  .lesson-poster small{left:18px;bottom:16px}
  .lesson-facts{grid-template-columns:1fr;margin:24px 0}
  .lesson-facts div{padding:10px 0}
  .lesson-workbench{margin:45px 0}
  .lesson-workbench>div{padding:30px 22px}
  .lesson-workbench h2{font-size:38px}
  .lesson-workbench li{grid-template-columns:40px 1fr;padding:22px}
  .lesson-summary{margin:60px auto;padding:0 12px}
  .lesson-summary p{font-size:16px}
  .lesson-routes,.lesson-related{margin:65px 0}
  .lesson-routes>div:first-child,.lesson-section-head{align-items:flex-start;flex-direction:column}
  .lesson-route-grid,.lesson-card-grid{grid-template-columns:1fr}
  .lesson-conversion{margin:65px 0 35px;padding:42px 22px}
  .lesson-conversion h2{font-size:42px}
  .lesson-conversion>div{align-items:stretch;flex-direction:column}
  .lesson-footer{flex-direction:column;padding:28px 20px}
  .lesson-footer nav{flex-wrap:wrap}
  .route-hero{min-height:0;padding:38px 22px;gap:34px}
  .route-hero h1{font-size:clamp(54px,18vw,78px)}
  .route-catalog{margin:65px 0}
  .route-list a{grid-template-columns:34px 1fr;gap:13px;padding:15px 0}
  .route-list img{grid-column:2;width:100%}
  .route-list__copy{grid-column:2}
  .route-list__number{grid-row:1 / span 2;align-self:start;padding-top:5px}
  .route-other{grid-template-columns:1fr}
  .route-other a{border-left:0;border-top:1px solid var(--line);padding-left:0}
}

@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}