/* ============ TOKENS ============ */
:root{
  --primary:#38bdf8; --secondary:#7c6cf6; --accent:#fbbf24; --danger:#fb7185;
  --background:#070d1a; --background-2:#0b1428;
  --surface:rgba(255,255,255,.045); --surface-2:rgba(13,22,42,.72);
  --text:#e8eef9; --muted:#9fb0c8;
  --grad:linear-gradient(120deg,var(--primary),var(--secondary) 55%,var(--accent));
  --border:rgba(148,184,255,.16);
  --r:18px; --font-d:"Sora",system-ui,sans-serif; --font-b:"Inter",system-ui,sans-serif;
  --shadow:0 20px 50px -20px rgba(2,8,23,.9);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-padding-top:110px}
@media (prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}
body{font-family:var(--font-b);background:var(--background);color:var(--text);line-height:1.75;overflow-x:hidden;
  background-image:radial-gradient(1100px 500px at 85% -10%,rgba(124,108,246,.16),transparent 60%),radial-gradient(900px 480px at -10% 25%,rgba(56,189,248,.12),transparent 60%);}
img{max-width:100%;display:block}
a{color:var(--primary);text-decoration:none}
article a,.contact a:not(.btn){text-decoration:underline;text-underline-offset:3px;text-decoration-color:rgba(56,189,248,.5)}
article a:hover{color:var(--accent)}
h1,h2,h3{font-family:var(--font-d);line-height:1.2}
.wrap{max-width:1160px;margin-inline:auto;padding-inline:clamp(16px,4vw,32px)}
:focus-visible{outline:2px solid var(--primary);outline-offset:3px;border-radius:6px}
::selection{background:rgba(124,108,246,.5)}
.skip{position:fixed;left:-999px;top:8px;z-index:99;background:var(--primary);color:#04101f;padding:10px 16px;border-radius:10px;font-weight:600}
.skip:focus{left:8px}
/* progress bar */
.bar{position:fixed;top:0;left:0;height:3px;width:0;background:var(--grad);z-index:60;box-shadow:0 0 12px rgba(56,189,248,.7)}
/* ============ HEADER ============ */
.header{position:fixed;inset:0 0 auto;z-index:50;transition:background .35s,border-color .35s,backdrop-filter .35s;border-bottom:1px solid transparent}
.header.scrolled{background:rgba(7,13,26,.78);backdrop-filter:blur(14px);border-color:var(--border)}
.h-in{display:flex;align-items:center;gap:22px;height:72px}
.logo{display:flex;align-items:center;gap:10px;color:var(--text);font-family:var(--font-d);font-weight:700;font-size:1.02rem;margin-right:auto}
.logo svg{width:30px;height:30px;filter:drop-shadow(0 0 8px rgba(56,189,248,.6))}
.logo small{display:block;font-size:.62rem;font-weight:500;color:var(--muted);letter-spacing:.14em;text-transform:uppercase}
.nav{display:flex;gap:4px}
.nav a{color:var(--muted);font-size:.9rem;font-weight:500;padding:8px 12px;border-radius:10px;transition:.25s}
.nav a:hover{color:var(--text);background:var(--surface);transform:translateY(-1px)}
.nav-toggle{display:none;background:none;border:0;cursor:pointer;padding:8px;flex-direction:column;gap:5px}
.nav-toggle span{width:22px;height:2px;background:var(--text);border-radius:2px;transition:.3s}
/* ============ BUTTONS ============ */
.btn{position:relative;display:inline-flex;align-items:center;gap:8px;font-weight:600;font-size:.95rem;color:#04101f;background:var(--grad);background-size:200% 100%;padding:13px 24px;border-radius:14px;overflow:hidden;transition:.35s;box-shadow:0 8px 24px -8px rgba(56,189,248,.55);border:0;cursor:pointer}
.btn:hover{transform:translateY(-3px);background-position:100% 0;box-shadow:0 14px 34px -8px rgba(124,108,246,.65)}
.btn svg{width:16px;height:16px}
.btn.ghost{background:var(--surface);color:var(--text);border:1px solid var(--border);box-shadow:none;backdrop-filter:blur(8px)}
.btn.ghost:hover{border-color:var(--primary);box-shadow:0 0 22px -6px rgba(56,189,248,.5)}
.btn-sm{padding:9px 16px;font-size:.85rem;border-radius:12px}
/* ============ HERO ============ */
.hero{position:relative;padding:150px 0 90px;overflow:hidden}
.orb{position:absolute;border-radius:50%;filter:blur(70px);opacity:.5;pointer-events:none;animation:float 12s ease-in-out infinite}
.o1{width:420px;height:420px;background:radial-gradient(circle,#1d4ed8,transparent 65%);top:-120px;right:-80px}
.o2{width:360px;height:360px;background:radial-gradient(circle,#7c6cf6,transparent 65%);bottom:-140px;left:-100px;animation-delay:-4s}
.o3{width:220px;height:220px;background:radial-gradient(circle,#fbbf24,transparent 65%);top:30%;left:44%;opacity:.28;animation-delay:-8s}
.grid-lines{position:absolute;inset:0;background-image:linear-gradient(rgba(148,184,255,.07) 1px,transparent 1px),linear-gradient(90deg,rgba(148,184,255,.07) 1px,transparent 1px);background-size:56px 56px;mask-image:radial-gradient(ellipse 70% 60% at 50% 40%,#000,transparent);transform:perspective(600px) rotateX(38deg);transform-origin:top}
.stars{position:absolute;inset:0;background-image:radial-gradient(rgba(255,255,255,.16) 1px,transparent 1px);background-size:30px 30px;mask-image:linear-gradient(#000 20%,transparent 80%);animation:drift 70s linear infinite}
@keyframes drift{to{background-position:300px 600px}}
@keyframes float{0%,100%{transform:translate3d(0,0,0)}50%{transform:translate3d(0,-26px,0)}}
.hero-grid{position:relative;display:grid;grid-template-columns:1.08fr .92fr;gap:52px;align-items:center}
.tag{display:inline-flex;align-items:center;gap:8px;font-size:.78rem;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--primary);background:var(--surface);border:1px solid var(--border);padding:7px 14px;border-radius:99px;backdrop-filter:blur(8px)}
.tag i{width:7px;height:7px;border-radius:50%;background:var(--accent);box-shadow:0 0 10px var(--accent);animation:pulse 2s infinite}
@keyframes pulse{50%{opacity:.35}}
h1{font-size:clamp(2.1rem,4.6vw,3.5rem);font-weight:800;margin:20px 0 18px;letter-spacing:-.02em;text-shadow:0 8px 40px rgba(2,8,23,.8)}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;filter:drop-shadow(0 0 18px rgba(56,189,248,.35))}
.lead{color:var(--muted);font-size:1.08rem;max-width:56ch}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap;margin:28px 0 22px}
.hero-meta{display:flex;gap:10px;flex-wrap:wrap}
.hero-meta span{font-size:.8rem;color:var(--muted);background:var(--surface);border:1px solid var(--border);padding:6px 12px;border-radius:10px;backdrop-filter:blur(6px)}
.hero-visual{perspective:1100px}
.h-card{position:relative;border-radius:22px;overflow:visible;transform:perspective(1100px) rotateX(var(--rx,0deg)) rotateY(var(--ry,0deg));transition:transform .2s ease-out;box-shadow:var(--shadow)}
.h-card img{border-radius:22px;border:1px solid var(--border);aspect-ratio:4/3;object-fit:cover;box-shadow:0 30px 70px -30px rgba(56,189,248,.35)}
.chip{position:absolute;font-size:.78rem;font-weight:600;color:var(--text);background:rgba(10,18,36,.8);backdrop-filter:blur(10px);border:1px solid var(--border);padding:8px 14px;border-radius:12px;box-shadow:0 10px 26px -10px rgba(2,8,23,.9);animation:float 6s ease-in-out infinite}
.c1{top:-16px;left:-14px;border-color:rgba(56,189,248,.5)}
.c2{top:38%;right:-18px;animation-delay:-2s;border-color:rgba(124,108,246,.5)}
.c3{bottom:-14px;left:12%;animation-delay:-4s;border-color:rgba(251,191,36,.5)}
.scroll-ind{position:absolute;left:50%;bottom:14px;transform:translateX(-50%);display:flex;flex-direction:column;align-items:center;gap:8px;color:var(--muted);font-size:.72rem;letter-spacing:.2em;text-transform:uppercase}
.mouse{width:24px;height:40px;border:2px solid rgba(159,176,200,.5);border-radius:14px;display:flex;justify-content:center;padding-top:7px}
.mouse span{width:4px;height:8px;border-radius:4px;background:var(--primary);animation:wheel 1.8s infinite}
@keyframes wheel{0%{transform:translateY(0);opacity:1}70%{transform:translateY(12px);opacity:0}100%{opacity:0}}
/* ============ LAYOUT / TOC ============ */
.layout{display:grid;grid-template-columns:272px minmax(0,1fr);gap:40px;align-items:start;padding:30px 0 70px}
.toc-card{position:sticky;top:96px;background:var(--surface-2);backdrop-filter:blur(12px);border:1px solid var(--border);border-radius:var(--r);padding:20px;transform:perspective(900px) rotateX(var(--rx,0deg)) rotateY(var(--ry,0deg));transition:transform .2s,box-shadow .3s;box-shadow:var(--shadow)}
.toc-card:hover{box-shadow:0 24px 60px -24px rgba(56,189,248,.35)}
.toc-toggle{display:none;width:100%;background:none;border:0;color:var(--text);font:600 .95rem var(--font-d);cursor:pointer;align-items:center;justify-content:space-between}
.toc-toggle svg{width:18px;transition:.3s}
.toc-list{display:flex;flex-direction:column;gap:2px;max-height:62vh;overflow:auto}
.toc-list a{position:relative;display:block;color:var(--muted);font-size:.86rem;padding:7px 10px 7px 22px;border-radius:10px;transition:.25s}
.toc-list a::before{content:"";position:absolute;left:8px;top:50%;translate:0 -50%;width:6px;height:6px;border-radius:50%;background:var(--border);transition:.25s}
.toc-list a:hover{color:var(--text);background:var(--surface);transform:translateX(3px)}
.toc-list a.active{color:var(--text);background:linear-gradient(90deg,rgba(56,189,248,.16),transparent);font-weight:600}
.toc-list a.active::before{background:var(--grad);box-shadow:0 0 10px var(--primary);width:8px;height:8px}
.toc-prog{margin-top:14px;height:4px;border-radius:4px;background:var(--surface);overflow:hidden}
.toc-prog span{display:block;height:100%;width:0;background:var(--grad);transition:width .2s}
/* ============ ARTICLE ============ */
article{min-width:0}
.article-lead{font-size:1.12rem;color:var(--text);background:var(--surface);border:1px solid var(--border);border-left:4px solid var(--primary);border-radius:var(--r);padding:20px 24px;backdrop-filter:blur(8px);box-shadow:var(--shadow)}
article section{margin-top:52px}
article h2{font-size:clamp(1.35rem,2.6vw,1.7rem);font-weight:700;margin-bottom:18px;display:flex;align-items:center;gap:12px}
article h2::before{content:"";flex:0 0 26px;height:26px;border-radius:8px;background:var(--grad);box-shadow:0 0 16px rgba(56,189,248,.5);transform:rotate(45deg) scale(.82)}
article h3{font-size:1.08rem;margin:20px 0 10px}
article p{color:var(--muted);margin-bottom:14px}
article p strong,article li strong{color:var(--text)}
/* lists */
.check,.steps{list-style:none;margin:18px 0;display:flex;flex-direction:column;gap:10px}
.check li{position:relative;padding:12px 16px 12px 48px;background:var(--surface);border:1px solid var(--border);border-radius:14px;color:var(--muted);transition:.3s}
.check li::before{content:"✓";position:absolute;left:14px;top:12px;width:24px;height:24px;border-radius:8px;display:grid;place-items:center;font-size:.8rem;font-weight:700;color:#04101f;background:var(--grad);box-shadow:0 0 12px rgba(56,189,248,.45)}
.check li:hover{transform:translateX(6px);border-color:rgba(56,189,248,.45);color:var(--text)}
.steps{counter-reset:s}
.steps li{counter-increment:s;position:relative;padding:14px 18px 14px 60px;background:var(--surface);border:1px solid var(--border);border-radius:14px;color:var(--muted);transition:.3s}
.steps li::before{content:counter(s,decimal-leading-zero);position:absolute;left:14px;top:14px;font:800 .95rem var(--font-d);background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;filter:drop-shadow(0 0 8px rgba(124,108,246,.6))}
.steps li:hover{transform:translateY(-3px);border-color:rgba(124,108,246,.5)}
/* note boxes */
.note{border-radius:var(--r);padding:18px 22px;margin:22px 0;border:1px solid;background:var(--surface-2);backdrop-filter:blur(8px);color:var(--muted);box-shadow:var(--shadow)}
.note strong{color:var(--text)}
.n-amber{border-color:rgba(251,191,36,.45);box-shadow:0 0 34px -14px rgba(251,191,36,.45)}
.n-red{border-color:rgba(251,113,133,.45);box-shadow:0 0 34px -14px rgba(251,113,133,.5)}
/* cards / duo */
.duo{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:22px 0}
.card{border:1px solid transparent;border-radius:var(--r);padding:22px;background:linear-gradient(var(--surface-2),var(--surface-2)) padding-box,linear-gradient(135deg,rgba(56,189,248,.55),rgba(124,108,246,.3),rgba(251,191,36,.35)) border-box;box-shadow:var(--shadow);transform:perspective(900px) rotateX(var(--rx,0deg)) rotateY(var(--ry,0deg));transition:transform .2s,box-shadow .3s}
.card:hover{box-shadow:0 26px 60px -22px rgba(56,189,248,.4)}
.card h3{margin:0 0 12px}
.card ul{list-style:none;display:flex;flex-direction:column;gap:8px;color:var(--muted);font-size:.93rem}
.card ul li::before{content:"→ ";color:var(--primary)}
.replace ul li::before{color:var(--accent)}
/* figures */
.frame{margin:26px 0;border-radius:20px;padding:6px;background:linear-gradient(var(--background-2),var(--background-2)) padding-box,linear-gradient(135deg,rgba(56,189,248,.6),rgba(124,108,246,.4),rgba(251,191,36,.5)) border-box;border:1px solid transparent;box-shadow:var(--shadow);overflow:hidden}
.frame img{border-radius:14px;aspect-ratio:16/9;object-fit:cover;transition:transform .9s ease;will-change:transform}
.frame:hover img{transform:scale(1.05)}
.frame figcaption{padding:12px 8px 4px;font-size:.82rem;color:var(--muted);text-align:center}
/* takeaways */
.keys{list-style:none;counter-reset:k;display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:20px 0}
.keys li{counter-increment:k;position:relative;padding:16px 18px 14px 58px;background:var(--surface);border:1px solid var(--border);border-radius:16px;color:var(--muted);font-size:.93rem;transition:.3s}
.keys li::before{content:counter(k,decimal-leading-zero);position:absolute;left:16px;top:16px;font:800 1rem var(--font-d);background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.keys li:hover{transform:translateY(-5px) rotateX(2deg);border-color:rgba(251,191,36,.5);box-shadow:0 18px 40px -18px rgba(251,191,36,.35)}
/* ============ CONTACT ============ */
.contact-wrap{padding-bottom:80px}
.contact{position:relative;overflow:hidden;display:grid;grid-template-columns:1.1fr .9fr;gap:34px;align-items:center;border-radius:26px;padding:clamp(26px,4vw,46px);background:var(--surface-2);border:1px solid transparent;background-clip:padding-box;box-shadow:0 30px 80px -30px rgba(56,189,248,.35);backdrop-filter:blur(14px);transform:perspective(1100px) rotateX(var(--rx,0deg)) rotateY(var(--ry,0deg));transition:transform .2s}
.contact::before{content:"";position:absolute;inset:0;border-radius:26px;padding:1px;background:var(--grad);-webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;pointer-events:none}
.c-orb{position:absolute;width:340px;height:340px;right:-120px;top:-120px;border-radius:50%;background:radial-gradient(circle,rgba(56,189,248,.35),transparent 65%);filter:blur(30px);animation:float 10s ease-in-out infinite}
.contact h2{font-size:clamp(1.5rem,3vw,2.1rem);margin:16px 0 12px}
.contact p{color:var(--muted)}
.c-loc{font-weight:600;color:var(--text)}
.c-actions{display:grid;gap:12px;position:relative}
.c-actions .btn{justify-content:center;flex-wrap:wrap}
/* ============ FOOTER ============ */
.footer{border-top:1px solid var(--border);padding:30px 0;background:rgba(7,13,26,.6)}
.f-in{display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;color:var(--muted);font-size:.88rem}
.f-sub{color:var(--secondary)}
/* ============ REVEAL ============ */
.reveal{opacity:0;transform:translateY(26px) scale(.98);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
/* ============ RESPONSIVE ============ */
@media (max-width:1000px){
  .hero-grid{grid-template-columns:1fr;gap:44px}
  .hero-visual{max-width:560px}
  .layout{grid-template-columns:1fr}
  .toc-card{position:static}
  .toc-toggle{display:flex}
  .toc-list{max-height:0;overflow:hidden;transition:max-height .45s ease}
  .toc.open .toc-list{max-height:420px;overflow:auto;margin-top:12px}
  .toc.open .toc-toggle svg{transform:rotate(180deg)}
  .contact{grid-template-columns:1fr}
}
@media (max-width:860px){
  .nav{position:absolute;top:72px;left:0;right:0;flex-direction:column;background:rgba(7,13,26,.96);backdrop-filter:blur(16px);border-bottom:1px solid var(--border);padding:14px 20px;display:none}
  body.nav-open .nav{display:flex}
  .nav-toggle{display:flex}
  body.nav-open .nav-toggle span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  body.nav-open .nav-toggle span:nth-child(2){opacity:0}
  body.nav-open .nav-toggle span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
  .btn-sm{display:none}
}
@media (max-width:640px){
  .duo,.keys{grid-template-columns:1fr}
  .hero{padding-top:120px}
  .c2{right:0}
}
/* ============ REDUCED MOTION ============ */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal{opacity:1;transform:none}
  html{scroll-behavior:auto}
}