:root{
  --bg:#f6f8fc; --card:#fff; --ink:#0b1220; --muted:#5b667a;
  --line:#e3e8f1; --blue:#2563eb; --blue2:#1d4ed8;
  --navy:#0b1220; --navy2:#121d33; --soft:#eef4ff;
  --shadow:0 24px 80px rgba(11,18,32,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:"Noto Sans CJK SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button{font-family:inherit}
.nav{
  position:sticky;top:0;z-index:30;display:flex;align-items:center;gap:28px;
  padding:14px clamp(18px,4vw,56px);background:rgba(11,18,32,.88);backdrop-filter:blur(14px);
  color:#fff;border-bottom:1px solid rgba(255,255,255,.08)
}
.logo{font-weight:900;letter-spacing:-.02em;font-size:18px;display:flex;align-items:baseline;gap:10px}
.logo span{font-size:12px;font-weight:500;color:#aab7d0;letter-spacing:.06em}
.nav-links{display:flex;gap:22px;margin-left:auto;font-size:14px;color:#c9d3e6}
.nav-links a:hover{color:#fff}
.nav-actions{display:flex;align-items:center;gap:14px;margin-left:8px}
.teacher-link{font-size:13px;color:#c9d3e6}
.teacher-link:hover{color:#fff}
.btn{
  display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:0 20px;
  border-radius:12px;border:1px solid var(--line);background:#fff;color:var(--ink);
  font-weight:800;font-size:14px;cursor:pointer;transition:transform .15s,box-shadow .15s,background .15s
}
.btn:hover{transform:translateY(-1px);box-shadow:0 10px 28px rgba(11,18,32,.12)}
.btn.primary{background:var(--blue);border-color:var(--blue);color:#fff}
.btn.primary:hover{background:var(--blue2)}
.btn.small{min-height:38px;padding:0 14px;font-size:13px;border-radius:10px}
.btn.ghost{background:transparent;border-color:rgba(255,255,255,.28);color:#fff}
.btn.large{min-height:54px;padding:0 26px;font-size:16px}
.hero{
  display:grid;grid-template-columns:1.08fr .92fr;gap:40px;align-items:center;
  max-width:1200px;margin:0 auto;padding:clamp(50px,7vw,96px) clamp(18px,4vw,56px) 70px;
  background:radial-gradient(900px 500px at 80% 30%,rgba(37,99,235,.26),transparent 60%);
  border-radius:0 0 32px 32px;color:#fff;position:relative;overflow:hidden
}
.hero:before{
  content:"";position:absolute;inset:0;background:linear-gradient(135deg,#0b1220,#121d33 55%,#0b1220);z-index:-1
}
.eyebrow{font-size:12px;font-weight:900;letter-spacing:.14em;text-transform:uppercase;color:#6ea0ff}
.hero h1{font-size:clamp(40px,5.4vw,68px);line-height:1.06;letter-spacing:-.045em;margin:14px 0 18px;font-weight:900}
.hero h1 span{color:#9cc0ff}
.lead{font-size:clamp(16px,1.7vw,19px);color:#c7d2e6;max-width:590px;margin:0 0 28px}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px}
.hero-meta{display:flex;flex-wrap:wrap;gap:22px;margin-top:30px;color:#9fb0cb;font-size:13px}
.hero-meta b{color:#fff;margin-right:6px}
.hero-visual{position:relative;min-height:430px;display:flex;align-items:center;justify-content:center}
.orbit-core{
  width:140px;height:140px;border-radius:50%;background:linear-gradient(145deg,#2f6df0,#1748b8);
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  font-weight:900;font-size:23px;line-height:1.1;box-shadow:0 0 0 18px rgba(37,99,235,.12),0 30px 70px rgba(37,99,235,.35);z-index:2
}
.orbit-core small{font-size:10px;letter-spacing:.14em;font-weight:700;color:#cfe0ff;margin-top:3px}
.orbit-card{
  position:absolute;min-width:150px;background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.14);
  border-radius:15px;padding:13px 15px;backdrop-filter:blur(12px);box-shadow:0 20px 50px rgba(0,0,0,.2)
}
.orbit-card span{display:block;font-size:10px;letter-spacing:.1em;color:#8fa6c8;text-transform:uppercase}
.orbit-card b{display:block;font-size:19px;margin:2px 0}
.orbit-card small{font-size:11px;color:#aebbd2}
.orbit-card.goal{top:10px;left:0}
.orbit-card.brain{top:34px;right:0}
.orbit-card.tool{bottom:44px;left:12px}
.orbit-card.memory{bottom:0;right:10px}
.section{max-width:1200px;margin:0 auto;padding:clamp(54px,7vw,92px) clamp(18px,4vw,56px)}
.section-head{max-width:760px;margin-bottom:34px}
.section-head h2,.outcome-copy h2{font-size:clamp(30px,3.8vw,46px);line-height:1.12;letter-spacing:-.035em;margin:10px 0 12px}
.section-head p,.outcome-copy p{color:var(--muted);font-size:16px;margin:0}
.pain-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.pain-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:22px;box-shadow:0 10px 30px rgba(11,18,32,.04)}
.pain-card .num{font-size:12px;font-weight:900;color:#9aa7bd;letter-spacing:.1em}
.pain-card h3{font-size:17px;margin:12px 0 8px}
.pain-card p{font-size:14px;color:var(--muted);margin:0}
.courses{background:linear-gradient(180deg,#eef3fb,transparent 65%)}
.course-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.course-card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:26px;display:flex;flex-direction:column;box-shadow:0 16px 44px rgba(11,18,32,.05)}
.course-card.featured{border-color:#9db9f7;box-shadow:0 24px 60px rgba(37,99,235,.14);position:relative}
.course-card.featured:before{content:"推荐";position:absolute;top:18px;right:18px;background:var(--soft);color:var(--blue);font-size:11px;font-weight:900;padding:5px 10px;border-radius:999px}
.course-top{display:flex;align-items:center;gap:10px;margin-bottom:18px}
.tag{background:var(--navy);color:#fff;font-size:12px;font-weight:900;border-radius:8px;padding:5px 9px;letter-spacing:.04em}
.duration{font-size:12px;color:var(--muted)}
.course-card h3{font-size:28px;letter-spacing:-.03em;margin:0 0 8px}
.course-sub{font-size:14px;color:var(--muted);margin:0 0 16px}
.course-card ul{padding-left:18px;margin:0 0 18px;color:#344054;font-size:14px}
.course-card li{margin:7px 0}
.course-fit{margin-top:auto;background:#f8fafc;border:1px solid var(--line);border-radius:11px;padding:10px 12px;font-size:12px;color:var(--muted)}
.outcomes{display:grid;grid-template-columns:.9fr 1.1fr;gap:40px;align-items:center}
.outcome-list{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.outcome-list>div{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px}
.outcome-list b{color:var(--blue);font-size:12px;letter-spacing:.1em}
.outcome-list span{display:block;font-weight:800;font-size:17px;margin:5px 0 2px}
.outcome-list small{color:var(--muted);font-size:13px}
.cta-band{
  max-width:1200px;margin:0 auto 70px;padding:38px clamp(24px,4vw,46px);
  background:linear-gradient(135deg,#0b1220,#1a2b4e);color:#fff;border-radius:26px;
  display:flex;align-items:center;justify-content:space-between;gap:30px;box-shadow:var(--shadow)
}
.cta-band h2{font-size:clamp(24px,3vw,36px);line-height:1.15;letter-spacing:-.03em;margin:8px 0 8px}
.cta-band p{color:#bfcce2;margin:0;font-size:14px}
.footer{display:flex;flex-wrap:wrap;justify-content:space-between;gap:14px;padding:26px clamp(18px,4vw,56px);border-top:1px solid var(--line);color:var(--muted);font-size:13px}
.footer a{color:var(--blue)}
.modal{position:fixed;inset:0;z-index:100;display:flex;align-items:center;justify-content:center;padding:20px}
.modal[hidden]{display:none}
.modal-backdrop{position:absolute;inset:0;background:rgba(11,18,32,.62);backdrop-filter:blur(6px)}
.modal-card{position:relative;width:100%;max-width:460px;background:#fff;border-radius:22px;padding:30px;box-shadow:0 40px 100px rgba(0,0,0,.3);max-height:92vh;overflow:auto}
.modal-card h2{font-size:28px;letter-spacing:-.03em;margin:8px 0 4px}
.modal-close{position:absolute;top:14px;right:16px;width:34px;height:34px;border:0;border-radius:50%;background:#f1f4f9;color:#475467;font-size:22px;cursor:pointer}
.modal-card form{display:flex;flex-direction:column;gap:12px;margin-top:18px}
.modal-card label{font-size:13px;color:#475467;font-weight:700}
.modal-card input,.modal-card textarea{display:block;width:100%;margin-top:6px;padding:12px 13px;border:1px solid var(--line);border-radius:11px;font-size:15px;font-family:inherit;background:#fff}
.modal-card input:focus,.modal-card textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.1)}
.modal-card .btn{width:100%;margin-top:4px}
.form-error{background:#fef2f2;color:#dc2626;border-radius:9px;padding:9px 11px;font-size:13px;margin:0}
.form-success{text-align:center;padding:18px 0 4px}
.success-mark{width:56px;height:56px;border-radius:50%;background:#ecfdf3;color:#16a34a;font-size:28px;font-weight:900;display:flex;align-items:center;justify-content:center;margin:0 auto 12px}
.muted{color:var(--muted)}
@media(max-width:960px){
  .hero{grid-template-columns:1fr;padding-bottom:46px}
  .hero-visual{min-height:360px;max-width:520px;margin:0 auto;width:100%}
  .pain-grid{grid-template-columns:1fr 1fr}
  .course-grid{grid-template-columns:1fr}
  .outcomes{grid-template-columns:1fr}
  .nav-links{display:none}
}
@media(max-width:620px){
  .nav{gap:12px;padding:12px 16px}
  .logo span{display:none}
  .nav-actions{gap:8px}
  .teacher-link{display:none}
  .hero{padding-top:42px}
  .hero-visual{min-height:330px}
  .orbit-card{min-width:128px;padding:10px 12px}
  .orbit-card b{font-size:16px}
  .orbit-card.goal{left:0;top:0}
  .orbit-card.brain{right:0;top:18px}
  .orbit-card.tool{left:0;bottom:26px}
  .orbit-card.memory{right:0;bottom:0}
  .pain-grid{grid-template-columns:1fr}
  .cta-band{flex-direction:column;align-items:flex-start;margin-left:16px;margin-right:16px}
  .outcome-list{grid-template-columns:1fr}
}