:root{
  --bg:#f5f7fb;
  --paper:#ffffff;
  --ink:#101827;
  --muted:#657085;
  --line:#e6eaf0;
  --navy:#111c34;
  --blue:#4967e8;
  --blue-2:#7388f3;
  --mint:#dff7ed;
  --mint-ink:#176b52;
  --peach:#fff0e7;
  --peach-ink:#a24b2b;
  --lav:#eeeaff;
  --lav-ink:#5a45a8;
  --yellow:#fff7cf;
  --shadow:0 18px 55px rgba(16,24,39,.08);
  --shadow-sm:0 8px 26px rgba(16,24,39,.06);
  --r:24px;
  --r-sm:16px;
  --max:1180px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.65}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.container,.gf-container{width:min(var(--max),calc(100% - 40px));margin:0 auto}

/* Header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(245,247,251,.88);backdrop-filter:blur(18px);border-bottom:1px solid rgba(230,234,240,.85)}
.header-inner{height:76px;display:flex;align-items:center;justify-content:space-between;gap:30px}
.gf-brand{display:flex;align-items:center;gap:11px;font-weight:800;letter-spacing:-.04em}
.gf-logo-symbol{width:34px;height:34px;border-radius:11px;background:var(--navy);display:grid;grid-template-columns:repeat(3,1fr);gap:3px;padding:7px;box-shadow:0 5px 16px rgba(17,28,52,.18)}
.gf-logo-symbol span{border-radius:5px;background:#fff}
.gf-logo-symbol span:nth-child(2){opacity:.68;transform:translateY(4px)}
.gf-logo-symbol span:nth-child(3){opacity:.4;transform:translateY(8px)}
.gf-logo-word{font-size:17px}
.nav{display:flex;gap:30px;font-size:14px;font-weight:600;color:#566174}
.nav a{transition:.2s}
.nav a:hover{color:var(--ink)}

/* Hero */
.hero{padding:72px 0 40px}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:28px;align-items:stretch}
.hero-copy,.hero-panel{border-radius:32px}
.hero-copy{padding:60px;background:var(--paper);border:1px solid var(--line);box-shadow:var(--shadow)}
.eyebrow,.section-kicker,.gf-eyebrow,.gf-section-kicker{font-size:11px;font-weight:800;letter-spacing:.16em;text-transform:uppercase;color:var(--blue)}
.hero h1{font-size:clamp(44px,5vw,74px);line-height:1.02;letter-spacing:-.065em;margin:18px 0 22px;max-width:720px}
.hero h1 em,.gf-hero-copy h1 em{font-family:Georgia,serif;font-weight:400;color:var(--blue)}
.hero p{font-size:18px;line-height:1.7;color:var(--muted);max-width:650px}
.hero-actions{display:flex;gap:12px;margin-top:30px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:0 20px;border-radius:14px;font-weight:700;font-size:14px;border:1px solid var(--line)}
.btn-dark{background:var(--navy);color:#fff;border-color:var(--navy)}
.btn-light{background:#fff}
.hero-panel{position:relative;overflow:hidden;padding:38px;background:linear-gradient(145deg,#111c34,#293d69);color:#fff;min-height:470px;box-shadow:var(--shadow)}
.hero-panel:before{content:"";position:absolute;width:330px;height:330px;border:1px solid rgba(255,255,255,.18);border-radius:50%;right:-90px;top:-75px}
.hero-panel:after{content:"";position:absolute;width:210px;height:210px;border:1px solid rgba(255,255,255,.15);border-radius:50%;right:-20px;top:35px}
.hero-panel-label{position:relative;z-index:1;font-size:11px;letter-spacing:.16em;color:#b9c5df}
.hero-panel-title{position:relative;z-index:1;font-size:39px;line-height:1.08;letter-spacing:-.05em;margin-top:100px;max-width:450px}
.hero-panel-stat{position:absolute;bottom:36px;left:38px;right:38px;border-top:1px solid rgba(255,255,255,.16);padding-top:20px;display:flex;align-items:baseline;gap:10px}
.hero-panel-stat strong{font-size:42px;letter-spacing:-.06em}
.hero-panel-stat span{color:#b9c5df;font-size:13px}

/* Topic bar */
.topic-strip{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.topic-inner{min-height:68px;display:flex;align-items:center;gap:22px}
.topic-label{font-size:11px;font-weight:800;letter-spacing:.13em;text-transform:uppercase;color:#8992a4;white-space:nowrap}
.topic-scroll{display:flex;gap:9px;overflow:auto;scrollbar-width:none}
.topic-scroll::-webkit-scrollbar{display:none}
.topic-pill{padding:8px 13px;border:1px solid var(--line);border-radius:999px;background:#fafbfc;font-size:12px;font-weight:650;white-space:nowrap;transition:.2s}
.topic-pill:hover{border-color:#c9d1e0;background:#fff;transform:translateY(-1px)}

/* Sections */
.section{padding:76px 0}
.section-head,.gf-section-heading{display:flex;justify-content:space-between;align-items:end;gap:25px;margin-bottom:24px}
.section-title,.gf-section-heading h2{font-size:34px;line-height:1.1;letter-spacing:-.05em;margin:6px 0 0}
.section-note,.gf-heading-note{font-size:13px;color:#8a94a6}
.feature{display:grid;grid-template-columns:1.1fr .9fr;background:#fff;border:1px solid var(--line);border-radius:28px;overflow:hidden;box-shadow:var(--shadow-sm);transition:.25s}
.feature:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.feature-media{min-height:390px;background:#eef1f7}
.feature-media img{width:100%;height:100%;object-fit:cover}
.feature-content{padding:48px;display:flex;flex-direction:column;justify-content:center}
.feature-tag,.meta__category{display:inline-flex;align-items:center;color:var(--blue);font-size:11px;font-weight:800;letter-spacing:.08em;text-transform:uppercase}
.feature-content h2{font-size:38px;line-height:1.1;letter-spacing:-.05em;margin:15px 0}
.feature-content p{color:var(--muted);font-size:16px}
.read-more,.article-link{font-size:13px;font-weight:800;margin-top:18px;color:var(--ink)}

/* Content layout */
.content-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:28px}
.article-list{display:grid;gap:14px}
.article-card{display:grid;grid-template-columns:235px 1fr;background:#fff;border:1px solid var(--line);border-radius:20px;overflow:hidden;transition:.2s}
.article-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-sm)}
.article-thumb{background:#edf0f5;min-height:210px}
.article-thumb img{width:100%;height:100%;object-fit:cover}
.article-body{padding:26px 28px}
.article-meta{display:flex;gap:8px;align-items:center;font-size:11px;color:#8b94a5;text-transform:uppercase;letter-spacing:.07em;font-weight:700}
.article-meta a{color:var(--blue)}
.article-body h3{font-size:23px;line-height:1.22;letter-spacing:-.035em;margin:9px 0}
.article-body p{margin:0;color:var(--muted);font-size:14px;line-height:1.65}
.sidebar{display:grid;gap:16px;align-content:start}
.sidebox{padding:25px;background:#fff;border:1px solid var(--line);border-radius:20px}
.sidebox.dark{background:var(--navy);color:#fff;border-color:var(--navy)}
.side-title{font-size:10px;letter-spacing:.15em;text-transform:uppercase;font-weight:800;color:#8792a8;margin-bottom:15px}
.dark .side-title{color:#aebbd7}
.sidebox h3{font-size:24px;line-height:1.2;letter-spacing:-.04em;margin:0 0 12px}
.sidebox p{font-size:13px;color:#768196;margin:0}
.dark p{color:#b7c1d3}
.sidecat{display:flex;justify-content:space-between;gap:10px;padding:11px 0;border-bottom:1px solid var(--line);font-size:13px}
.sidecat:last-child{border-bottom:0}
.sidecat small{color:#8d97a8}
.pagination{display:flex;justify-content:center;align-items:center;gap:7px;margin-top:34px}
.pagination a,.pagination span{width:40px;height:40px;border-radius:12px;display:grid;place-items:center;border:1px solid var(--line);background:#fff;font-size:13px}
.pagination a.active{background:var(--navy);color:#fff;border-color:var(--navy)}

/* Principles */
.principles{background:var(--navy);color:#fff;padding:80px 0}
.principles-grid{display:grid;grid-template-columns:1fr 1fr;gap:80px}
.principles h2{font-size:46px;line-height:1.08;letter-spacing:-.055em;margin:15px 0}
.principles h2 em{font-family:Georgia,serif;font-weight:400;color:#a9b9ff}
.principle{display:grid;grid-template-columns:55px 1fr;gap:15px;padding:22px 0;border-bottom:1px solid rgba(255,255,255,.12)}
.principle strong{color:#93a5df;font-size:12px;letter-spacing:.08em}
.principle span{color:#c2cada;font-size:14px}

/* Category */
.gf-category-hero{padding:55px 0 40px;background:#fff;border-bottom:1px solid var(--line)}
.gf-breadcrumbs{display:flex;gap:10px;align-items:center;font-size:12px;color:#8a94a6;margin-bottom:40px}
.gf-breadcrumbs a{color:var(--blue)}
.gf-hero-grid{display:grid;grid-template-columns:1fr 390px;gap:60px;align-items:center}
.gf-hero-copy h1{font-size:clamp(44px,5.5vw,70px);line-height:1.02;letter-spacing:-.065em;margin:16px 0 20px}
.gf-hero-copy p{max-width:650px;color:var(--muted);font-size:17px}
.gf-hero-stats{display:flex;align-items:center;gap:22px;margin-top:28px}
.gf-hero-stats strong{font-size:31px;letter-spacing:-.05em}
.gf-hero-stats span{display:block;font-size:11px;color:#8a94a6;text-transform:uppercase;letter-spacing:.08em}
.gf-hero-stats i{height:36px;width:1px;background:var(--line)}
.gf-hero-art{height:360px;border-radius:28px;background:linear-gradient(135deg,#e8edff,#f7f9ff);position:relative;overflow:hidden}
.gf-grid-lines{position:absolute;inset:0;background-image:linear-gradient(rgba(73,103,232,.08) 1px,transparent 1px),linear-gradient(90deg,rgba(73,103,232,.08) 1px,transparent 1px);background-size:35px 35px}
.gf-orbit{position:absolute;border:1px solid rgba(73,103,232,.35);border-radius:50%;left:50%;top:50%;transform:translate(-50%,-50%) rotate(-20deg)}
.orbit-a{width:285px;height:150px}.orbit-b{width:215px;height:285px}.orbit-c{width:340px;height:330px}
.gf-orbit-center{position:absolute;width:58px;height:58px;border-radius:18px;background:var(--navy);left:50%;top:50%;transform:translate(-50%,-50%);box-shadow:0 14px 28px rgba(17,28,52,.2)}
.gf-point{position:absolute;width:12px;height:12px;border-radius:50%;background:var(--blue)}
.p1{left:17%;top:27%}.p2{right:17%;top:58%}.p3{left:35%;bottom:13%}
.gf-plus{position:absolute;color:#7f90e9;font-size:20px;font-weight:800}.plus1{left:20%;bottom:24%}.plus2{right:20%;top:20%}
.gf-hero-art small{position:absolute;left:22px;bottom:20px;font-size:9px;letter-spacing:.16em;color:#6e7ca9;line-height:1.5}
.gf-selected-hero{display:flex;justify-content:space-between;gap:40px;align-items:end}
.gf-selected-hero h1{font-size:clamp(42px,6vw,68px);line-height:1;letter-spacing:-.065em;margin:15px 0}
.gf-selected-hero p{max-width:700px;color:var(--muted);font-size:17px}
.gf-selected-meta{display:flex;align-items:baseline;gap:9px;margin-top:25px}.gf-selected-meta strong{font-size:34px}.gf-selected-meta span{font-size:12px;color:#8a94a6}
.gf-selected-number{font-size:110px;line-height:.8;letter-spacing:-.08em;color:#edf0f6;font-weight:800}
.gf-category-section{padding:65px 0}
.gf-category-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.gf-category-card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:26px;min-height:260px;display:flex;flex-direction:column;transition:.23s}
.gf-category-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.gf-card-top,.gf-card-bottom{display:flex;justify-content:space-between;align-items:center}
.gf-card-index{font-size:11px;color:#9aa3b3;font-weight:800}
.gf-card-icon{width:38px;height:38px;border-radius:12px;background:var(--lav);color:var(--lav-ink);display:grid;place-items:center;font-weight:800}
.gf-category-card h3{font-size:24px;letter-spacing:-.04em;margin:25px 0 8px}
.gf-category-card p{font-size:13px;color:var(--muted);margin:0;line-height:1.6}
.gf-card-bottom{margin-top:auto;padding-top:20px;border-top:1px solid var(--line);font-size:11px;color:#8b94a5}
.gf-card-bottom b{color:var(--ink);font-size:18px}
.gf-material-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.gf-material-card{background:#fff;border:1px solid var(--line);border-radius:21px;overflow:hidden;transition:.22s}
.gf-material-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-sm)}
.gf-material-image{aspect-ratio:1.45;background:#eef1f6;overflow:hidden}
.gf-material-image img{width:100%;height:100%;object-fit:cover;transition:.4s}
.gf-material-card:hover img{transform:scale(1.025)}
.gf-material-body{padding:22px}
.gf-material-meta{display:flex;justify-content:space-between;gap:10px;font-size:10px;text-transform:uppercase;letter-spacing:.08em;color:#8993a4;font-weight:800}
.gf-material-meta span{color:var(--blue)}
.gf-material-body h3{font-size:21px;line-height:1.18;letter-spacing:-.035em;margin:12px 0 10px}
.gf-material-body p{font-size:13px;color:var(--muted);line-height:1.6;margin:0}
.gf-read{display:block;margin-top:18px;font-size:12px;font-weight:800}

/* Article */
.article-layout{display:grid;grid-template-columns:minmax(0,790px) 250px;gap:55px;justify-content:center}
.article{background:#fff;border:1px solid var(--line);border-radius:28px;padding:48px 58px;box-shadow:var(--shadow-sm)}
.article .breadcrumbs{font-size:12px;color:#8a94a6;margin-bottom:30px}.article .breadcrumbs a{color:var(--blue)}
.article h1{font-size:clamp(38px,5vw,60px);line-height:1.04;letter-spacing:-.06em;margin:13px 0 18px}
.article .lead{font-size:18px;color:#5e687a;line-height:1.7}
.article figure{margin:34px -20px 38px}
.article__hero{width:100%;border-radius:18px;max-height:520px;object-fit:cover}
.article h2{font-size:28px;line-height:1.18;letter-spacing:-.045em;margin:38px 0 13px}
.article p,.article li{font-size:16px;line-height:1.85;color:#394457}
.article ol{padding-left:25px}
.highlight-box,.exercise-step{margin:30px 0;padding:22px 24px;border-radius:17px;background:#f1f4ff;border:1px solid #dce3ff;color:#344267}
.article-aside{padding-top:90px}
.article-aside>div{position:sticky;top:105px}
.highlight-box strong{color:var(--blue)}

/* Footer */
.site-footer{background:#fff;border-top:1px solid var(--line);padding:58px 0 24px}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr;gap:55px}
.footer-brand{font-weight:800;font-size:20px;letter-spacing:-.04em}
.footer-grid p{color:#7a8496;font-size:13px;max-width:390px}
.footer-title{font-size:10px;text-transform:uppercase;letter-spacing:.15em;color:#8a94a6;font-weight:800;margin-bottom:13px}
.footer-links{display:grid;gap:9px;font-size:13px;font-weight:600}
.footer-bottom{border-top:1px solid var(--line);margin-top:40px;padding-top:20px;font-size:11px;color:#99a2b1}

/* Responsive */
@media(max-width:980px){
 .hero-grid,.gf-hero-grid{grid-template-columns:1fr}
 .hero-panel{min-height:390px}.hero-panel-title{margin-top:80px}
 .content-layout{grid-template-columns:1fr}.sidebar{grid-template-columns:1fr 1fr}
 .feature{grid-template-columns:1fr}.feature-media{min-height:280px}
 .principles-grid{grid-template-columns:1fr;gap:35px}
 .gf-category-grid,.gf-material-grid{grid-template-columns:repeat(2,1fr)}
 .article-layout{grid-template-columns:1fr}.article-aside{display:none}
}
@media(max-width:680px){
 .container,.gf-container{width:min(var(--max),calc(100% - 24px))}
 .header-inner{height:68px}.nav{gap:15px}.nav a:nth-child(2){display:none}
 .hero{padding-top:25px}.hero-copy{padding:32px 24px}.hero h1{font-size:45px}.hero-panel{min-height:350px;padding:27px}.hero-panel-title{font-size:31px;margin-top:70px}
 .topic-inner{padding:10px 0;align-items:flex-start;flex-direction:column;gap:8px}
 .section{padding:50px 0}.section-head,.gf-section-heading{align-items:flex-start;flex-direction:column;gap:8px}
 .article-card{grid-template-columns:1fr}.article-thumb{min-height:200px}.article-body{padding:22px}
 .feature-content{padding:30px 24px}.feature-content h2{font-size:30px}
 .sidebar{grid-template-columns:1fr}
 .principles{padding:60px 0}.principles h2{font-size:38px}
 .gf-category-grid,.gf-material-grid{grid-template-columns:1fr}.gf-hero-art{height:300px}
 .gf-selected-number{display:none}.gf-category-section{padding:45px 0}
 .article{padding:30px 22px;border-radius:20px}.article figure{margin-left:-8px;margin-right:-8px}.article h2{font-size:25px}
 .footer-grid{grid-template-columns:1fr;gap:25px}.footer-bottom{margin-top:25px}
}