/* iEdu Training — AI Power Education
   Independent sub-brand: editorial, confident, hand-built. No framework. */

:root{
  --ink:#0B1220;
  --ink-2:#2A3344;
  --ink-3:#697386;
  --paper:#F4F5F7;
  --paper-2:#FFFFFF;
  --line:#E2E5EA;
  --accent:#2F53FF;
  --accent-ink:#1B37C7;
  --warm:#FF6A3D;
  --ok:#0F9D58;
  --radius:16px;
  --maxw:1120px;
  --font-sans:"Inter","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --font-serif:"Newsreader","Songti SC",Georgia,"Times New Roman",serif;
  --font-mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font-sans);
  color:var(--ink);
  background:var(--paper);
  line-height:1.6;
  font-size:16px;
  letter-spacing:.002em;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.mono{font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3)}
.serif{font-family:var(--font-serif);font-weight:400;letter-spacing:-.01em}

/* Header */
.site-head{position:sticky;top:0;z-index:50;background:rgba(244,245,247,.82);backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line)}
.site-head .wrap{display:flex;align-items:center;justify-content:space-between;height:66px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:-.01em}
.brand b{font-weight:800}
.brand .dot{width:9px;height:9px;border-radius:50%;background:var(--accent);display:inline-block}
.brand small{display:block;font-family:var(--font-mono);font-size:10px;letter-spacing:.18em;color:var(--ink-3);text-transform:uppercase;font-weight:500}
.head-right{display:flex;align-items:center;gap:18px}
.lang{display:flex;gap:2px;border:1px solid var(--line);border-radius:999px;padding:3px;background:var(--paper-2)}
.lang button{border:0;background:transparent;font:inherit;font-size:12px;padding:4px 10px;border-radius:999px;cursor:pointer;color:var(--ink-3)}
.lang button[aria-pressed="true"]{background:var(--ink);color:#fff}
.nav-link{font-size:14px;color:var(--ink-2);font-weight:500}
.nav-link:hover{color:var(--ink)}

/* Buttons */
.btn{display:inline-flex;align-items:center;gap:8px;font:inherit;font-weight:600;font-size:15px;padding:12px 20px;border-radius:999px;border:1px solid transparent;cursor:pointer;transition:transform .15s ease,background .15s ease,color .15s ease,border-color .15s ease}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-ink)}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--ink)}
.btn-ghost:hover{border-color:var(--ink)}
.btn-ink{background:var(--ink);color:#fff}
.btn-ink:hover{background:#000}
.btn[disabled]{opacity:.55;cursor:not-allowed}

/* Hero */
.hero{padding:96px 0 72px;border-bottom:1px solid var(--line);position:relative;overflow:hidden}
.hero .eyebrow{margin-bottom:22px}
.hero h1{font-size:clamp(34px,5.4vw,68px);line-height:1.04;letter-spacing:-.03em;font-weight:800;max-width:16ch}
.hero h1 em{font-family:var(--font-serif);font-style:italic;font-weight:400;color:var(--accent)}
.hero p.lead{margin-top:26px;font-size:clamp(17px,1.5vw,20px);color:var(--ink-2);max-width:52ch}
.hero-cta{margin-top:36px;display:flex;gap:14px;flex-wrap:wrap}
.hero-strip{margin-top:56px;display:grid;grid-template-columns:repeat(3,1fr);gap:24px;border-top:1px solid var(--line);padding-top:26px}
.hero-strip .k{font-weight:700;font-size:15px;margin-bottom:4px}
.hero-strip .v{font-size:14px;color:var(--ink-3)}

/* Sections */
section{padding:80px 0}
.sec-head{display:grid;grid-template-columns:220px 1fr;gap:32px;align-items:start;margin-bottom:44px}
.sec-head h2{font-size:clamp(24px,3vw,38px);letter-spacing:-.02em;line-height:1.12;font-weight:750}
.sec-head p{color:var(--ink-2);max-width:56ch;margin-top:12px}

.grid{display:grid;gap:18px}
.g-2{grid-template-columns:1fr 1fr}
.g-3{grid-template-columns:repeat(3,1fr)}
.g-4{grid-template-columns:repeat(2,1fr)}
.card{background:var(--paper-2);border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.card .num{font-family:var(--font-mono);font-size:12px;color:var(--accent);letter-spacing:.14em}
.card h3{font-size:18px;margin:14px 0 8px;letter-spacing:-.01em}
.card p{color:var(--ink-3);font-size:14.5px}
.card ul{margin-top:12px;color:var(--ink-3);font-size:14.5px;padding-left:18px}
.card li{margin:4px 0}

.tick{list-style:none;display:grid;gap:16px}
.tick li{display:flex;gap:14px;align-items:flex-start;font-size:16px}
.tick svg{flex:none;margin-top:2px}

.split{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.stat-big{font-family:var(--font-serif);font-size:clamp(40px,6vw,72px);line-height:1;color:var(--accent);letter-spacing:-.02em}

.band{background:var(--ink);color:#fff}
.band .mono{color:#8C97AD}
.band .sec-head h2{color:#fff}
.band .sec-head p{color:#B7C0CF}
.band .card{background:#141C2E;border-color:#243049}
.band .card h3{color:#fff}
.band .card p,.band .card li{color:#9AA6BC}

.cta-final{background:var(--paper-2);border:1px solid var(--line);border-radius:24px;padding:56px;text-align:center}
.cta-final h2{font-size:clamp(26px,3.4vw,42px);letter-spacing:-.02em}
.cta-final p{color:var(--ink-3);margin:14px auto 28px;max-width:46ch}

/* Footer */
.site-foot{border-top:1px solid var(--line);padding:40px 0;color:var(--ink-3);font-size:13.5px}
.site-foot .wrap{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}

/* Intake form */
.intake-body{background:var(--paper);min-height:100vh}
.intake-shell{max-width:680px;margin:0 auto;padding:44px 24px 80px}
.intake-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:34px}
.progress{height:4px;background:var(--line);border-radius:99px;overflow:hidden;margin-bottom:34px}
.progress i{display:block;height:100%;width:33.33%;background:var(--accent);transition:width .35s cubic-bezier(.2,.7,.2,1)}
.steps{position:relative}
.step{display:none;animation:fade .35s ease}
.step.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.step h2{font-size:clamp(24px,3.4vw,34px);letter-spacing:-.02em;line-height:1.15;font-weight:750;margin-bottom:8px}
.step .sub{color:var(--ink-3);margin-bottom:30px}
.field{margin-bottom:22px}
.field label{display:block;font-weight:600;font-size:14px;margin-bottom:8px}
.field .hint{font-weight:400;color:var(--ink-3);font-size:13px}
.field input[type=text],.field input[type=email],.field textarea,.field select{
  width:100%;font:inherit;font-size:15px;padding:14px 16px;border:1px solid var(--line);
  border-radius:12px;background:var(--paper-2);color:var(--ink);outline:none;transition:border-color .15s,box-shadow .15s}
.field input:focus,.field textarea:focus{border-color:var(--accent);box-shadow:0 0 0 4px rgba(47,83,255,.12)}
.field textarea{resize:vertical;min-height:104px}
.seg{display:flex;gap:8px;flex-wrap:wrap}
.seg label{flex:1;min-width:120px;border:1px solid var(--line);border-radius:12px;padding:12px 14px;cursor:pointer;font-weight:500;font-size:14px;background:var(--paper-2);text-align:center;transition:.15s}
.seg input{position:absolute;opacity:0;pointer-events:none}
.seg label:has(input:checked){border-color:var(--accent);background:rgba(47,83,255,.06);color:var(--accent-ink);font-weight:600}
.form-actions{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:32px}
.err{color:#C0221A;font-size:13.5px;margin-top:10px;min-height:1em}
.done{text-align:center;padding:40px 0}
.done .badge{width:64px;height:64px;border-radius:50%;background:rgba(15,157,88,.1);display:grid;place-items:center;margin:0 auto 22px}

@media (max-width:860px){
  .sec-head{grid-template-columns:1fr;gap:14px}
  .split{grid-template-columns:1fr;gap:28px}
  .g-3,.g-4,.g-2{grid-template-columns:1fr}
  .hero-strip{grid-template-columns:1fr;gap:16px}
  .hero{padding:64px 0 48px}
  section{padding:56px 0}
  .cta-final{padding:36px 22px}
  .nav-link{display:none}
}