:root{
  --bg:#FBF4E8;
  --bg-soft:#F5EAD8;
  --card:#FFFDF8;
  --ink:#3B3229;
  --ink-2:#6E6154;
  --ink-3:#9A8C7C;
  --line:#E6D8C3;
  --brand:#C8622F;
  --brand-deep:#A44A1F;
  --accent:#3F7E6B;
  --cn:#C8622F;
  --en:#3F7E6B;
  --ma:#5B62A8;
  --r-lg:26px;
  --r-md:18px;
  --r-sm:12px;
  --shadow:0 10px 30px -18px rgba(90,60,30,.45);
  --shadow-lift:0 20px 44px -22px rgba(90,60,30,.5);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  background-image:radial-gradient(circle at 12% 0%,rgba(200,98,47,.07),transparent 42%),radial-gradient(circle at 92% 8%,rgba(63,126,107,.07),transparent 40%);
}
a{color:inherit;text-decoration:none}
img{display:block}

/* ---------- topbar ---------- */
.topbar{
  position:sticky;top:0;z-index:40;
  display:flex;align-items:center;gap:18px;
  padding:14px clamp(18px,5vw,56px);
  background:rgba(251,244,232,.86);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:.02em}
.brand-name{font-size:18px}
.topnav{display:flex;gap:22px;margin-left:auto;font-size:14.5px;color:var(--ink-2)}
.topnav a{position:relative;padding:4px 0;transition:color .2s}
.topnav a::after{content:"";position:absolute;left:0;bottom:0;height:2px;width:0;background:var(--brand);border-radius:2px;transition:width .22s}
.topnav a:hover{color:var(--brand-deep)}
.topnav a:hover::after{width:100%}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  border-radius:999px;font-weight:700;font-size:15px;
  padding:13px 26px;border:1.5px solid transparent;
  transition:transform .18s ease,box-shadow .18s ease,background .18s,color .18s;
  white-space:nowrap;
}
.btn-primary{background:var(--brand);color:#fff;box-shadow:0 12px 24px -14px rgba(164,74,31,.9)}
.btn-primary:hover{background:var(--brand-deep);transform:translateY(-2px);box-shadow:0 18px 30px -16px rgba(164,74,31,.9)}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--brand);color:var(--brand-deep);transform:translateY(-2px)}
.btn-sm{padding:9px 18px;font-size:14px}
.btn-lg{padding:16px 32px;font-size:16px}
.btn:focus-visible{outline:3px solid rgba(200,98,47,.35);outline-offset:3px}

/* ---------- hero ---------- */
.hero{
  display:grid;grid-template-columns:1.05fr .95fr;gap:clamp(28px,5vw,64px);
  align-items:center;
  padding:clamp(40px,6vw,84px) clamp(18px,5vw,56px) clamp(30px,4vw,56px);
  max-width:1240px;margin:0 auto;
}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:13px;font-weight:700;letter-spacing:.06em;
  color:var(--brand-deep);background:rgba(200,98,47,.1);
  padding:6px 14px;border-radius:999px;margin:0 0 20px;
}
.dot{width:7px;height:7px;border-radius:50%;background:var(--brand)}
.hero h1{
  font-size:clamp(34px,4.6vw,58px);line-height:1.18;letter-spacing:-.01em;
  margin:0 0 20px;font-weight:900;
}
.hero h1 em{
  font-style:normal;color:var(--brand);
  background:linear-gradient(transparent 62%,rgba(200,98,47,.18) 62%);
}
.lede{font-size:clamp(15px,1.5vw,17.5px);color:var(--ink-2);max-width:34em;margin:0 0 30px}
.cta-row{display:flex;flex-wrap:wrap;gap:12px}
.assure{list-style:none;display:flex;flex-wrap:wrap;gap:8px 22px;padding:0;margin:26px 0 0;font-size:14px;color:var(--ink-2)}
.assure li{display:flex;align-items:center;gap:7px}
.assure svg{width:16px;height:16px;color:var(--accent);flex:none}

/* hero stage */
.hero-stage{
  position:relative;min-height:400px;
  border-radius:34px;
  background:linear-gradient(150deg,var(--bg-soft),#FDF8EE 55%,#F3E7D4);
  border:1px solid var(--line);
  box-shadow:var(--shadow);
  overflow:hidden;
}
.hero-stage::before{
  content:"";position:absolute;inset:0;
  background-image:radial-gradient(rgba(164,74,31,.13) 1px,transparent 1px);
  background-size:22px 22px;opacity:.55;
}
.stage-card{
  position:absolute;background:var(--card);border:1px solid var(--line);
  border-radius:var(--r-md);padding:16px 18px;box-shadow:var(--shadow);
  transition:transform .25s ease;
}
.stage-card:hover{transform:translateY(-4px) rotate(0deg)}
.card-a{top:8%;left:7%;width:44%;transform:rotate(-3deg)}
.card-b{top:36%;right:5%;width:48%;transform:rotate(2.5deg);z-index:2}
.card-c{bottom:7%;left:14%;width:46%;transform:rotate(-1.5deg)}
.chip{
  display:inline-block;font-size:12px;font-weight:800;letter-spacing:.05em;
  padding:3px 10px;border-radius:999px;margin-bottom:8px;
}
.chip-cn{background:rgba(200,98,47,.14);color:var(--cn)}
.chip-en{background:rgba(63,126,107,.14);color:var(--en)}
.chip-ma{background:rgba(91,98,168,.14);color:var(--ma)}
.big-han{font-size:44px;font-weight:900;margin:0;line-height:1.1;color:var(--ink)}
.word{font-size:26px;font-weight:800;margin:0 0 2px;letter-spacing:-.01em}
.formula{font-size:24px;font-weight:800;margin:0 0 2px}
.formula b{color:var(--ma)}
.tiny{font-size:12px;color:var(--ink-3);margin:2px 0 0}
.bar{height:7px;border-radius:99px;background:var(--bg-soft);margin-top:12px;overflow:hidden}
.bar i{display:block;height:100%;border-radius:99px;background:linear-gradient(90deg,var(--cn),#E39A6B)}
.pills{display:flex;gap:6px;margin-top:10px}
.pills span{font-size:12px;font-weight:700;padding:2px 10px;border-radius:999px;background:rgba(63,126,107,.12);color:var(--en)}
.dots{display:flex;gap:6px;margin-top:12px}
.dots i{width:9px;height:9px;border-radius:50%;background:var(--bg-soft);border:1px solid var(--line)}
.dots i.on{background:var(--ma);border-color:var(--ma)}
.stage-code{
  position:absolute;right:6%;bottom:4%;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  font-size:11.5px;color:var(--ink-2);
  background:rgba(255,253,248,.9);border:1px dashed var(--line);
  padding:7px 12px;border-radius:10px;max-width:86%;
  overflow:hidden;text-overflow:ellipsis;white-space:nowrap;
}

/* ---------- generic section ---------- */
.section{padding:clamp(48px,6vw,88px) clamp(18px,5vw,56px);max-width:1240px;margin:0 auto}
.section-head{max-width:44em;margin-bottom:clamp(28px,4vw,48px)}
.section-head h2{font-size:clamp(26px,3.2vw,40px);line-height:1.25;margin:0 0 14px;font-weight:900;letter-spacing:-.01em}
.section-sub{color:var(--ink-2);margin:0;font-size:16px}

/* ---------- subjects ---------- */
.subject-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.subject{
  background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);
  padding:26px 24px 22px;box-shadow:var(--shadow);
  transition:transform .22s ease,box-shadow .22s ease;
  position:relative;overflow:hidden;
}
.subject::after{content:"";position:absolute;left:0;right:0;top:0;height:5px}
.subject-cn::after{background:var(--cn)}
.subject-en::after{background:var(--en)}
.subject-ma::after{background:var(--ma)}
.subject:hover{transform:translateY(-5px);box-shadow:var(--shadow-lift)}
.subject h3{font-size:20px;margin:0 0 16px;font-weight:800}
.item-list{list-style:none;margin:0;padding:0;display:grid;gap:11px}
.item-list li{
  display:flex;flex-direction:column;gap:1px;
  padding-bottom:11px;border-bottom:1px dashed var(--line);
}
.item-list li:last-child{border-bottom:0;padding-bottom:0}
.item-list b{font-size:15px;font-weight:800}
.item-list span{font-size:13.5px;color:var(--ink-3)}

/* ---------- embed ---------- */
.embed-section{max-width:none;background:var(--bg-soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.embed-inner{
  max-width:1240px;margin:0 auto;
  display:grid;grid-template-columns:1fr 1fr;gap:clamp(28px,5vw,60px);align-items:center;
}
.steps{list-style:none;margin:26px 0 0;padding:0;display:grid;gap:20px}
.steps li{display:flex;gap:16px;align-items:flex-start}
.step-no{
  flex:none;width:42px;height:42px;border-radius:14px;
  display:grid;place-items:center;
  background:var(--card);border:1px solid var(--line);
  font-family:ui-monospace,Menlo,monospace;font-size:14px;font-weight:800;color:var(--brand-deep);
  box-shadow:var(--shadow);
}
.steps h3{margin:0 0 3px;font-size:16.5px;font-weight:800}
.steps p{margin:0;font-size:14.5px;color:var(--ink-2)}
.code-card{
  background:#2F2A24;border-radius:var(--r-lg);overflow:hidden;
  box-shadow:0 24px 50px -26px rgba(47,42,36,.85);
  border:1px solid #463F36;
}
.code-bar{display:flex;align-items:center;gap:7px;padding:12px 16px;background:#3A342C;border-bottom:1px solid #4A4238}
.code-bar i{width:10px;height:10px;border-radius:50%;background:#6B6054}
.code-bar i:nth-child(1){background:#C8622F}
.code-bar i:nth-child(2){background:#C9A227}
.code-bar i:nth-child(3){background:#3F7E6B}
.code-bar span{margin-left:8px;font-size:12px;color:#B3A695;font-family:ui-monospace,Menlo,monospace}
.code-card pre{margin:0;padding:20px 18px;overflow-x:auto}
.code-card code{
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  font-size:13px;line-height:1.85;color:#EFE3D2;white-space:pre;
}
.code-note{margin:0;padding:0 18px 18px;font-size:12.5px;color:#A99B89}

/* ---------- scenes ---------- */
.scene-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.scene{
  background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);
  padding:28px 24px;box-shadow:var(--shadow);
  transition:transform .22s ease,box-shadow .22s ease;
}
.scene:hover{transform:translateY(-5px);box-shadow:var(--shadow-lift)}
.scene-icon{width:44px;height:44px;color:var(--brand);margin-bottom:16px}
.scene h3{margin:0 0 8px;font-size:18.5px;font-weight:800}
.scene p{margin:0;font-size:14.8px;color:var(--ink-2)}

/* ---------- faq ---------- */
.faq-section{max-width:900px}
.faq-list{display:grid;gap:12px}
.faq-list details{
  background:var(--card);border:1px solid var(--line);border-radius:var(--r-md);
  padding:0 22px;box-shadow:var(--shadow);
  transition:border-color .2s;
}
.faq-list details[open]{border-color:rgba(200,98,47,.45)}
.faq-list summary{
  cursor:pointer;list-style:none;padding:18px 30px 18px 0;position:relative;
  font-weight:800;font-size:16px;
}
.faq-list summary::-webkit-details-marker{display:none}
.faq-list summary::after{
  content:"";position:absolute;right:2px;top:50%;
  width:10px;height:10px;border-right:2px solid var(--brand);border-bottom:2px solid var(--brand);
  transform:translateY(-70%) rotate(45deg);transition:transform .2s;
}
.faq-list details[open] summary::after{transform:translateY(-30%) rotate(-135deg)}
.faq-list p{margin:0 0 18px;color:var(--ink-2);font-size:15px;max-width:60em}

/* ---------- final cta ---------- */
.final-cta{
  margin:0 clamp(18px,5vw,56px) clamp(48px,6vw,80px);
  max-width:1240px;
}
.final-inner{
  margin:0 auto;
  background:linear-gradient(135deg,#C8622F,#A44A1F 60%,#8C3C18);
  border-radius:32px;padding:clamp(30px,5vw,56px);
  display:flex;flex-wrap:wrap;gap:28px;align-items:center;justify-content:space-between;
  color:#FFF7ED;box-shadow:0 30px 60px -34px rgba(140,60,24,.9);
  position:relative;overflow:hidden;
}
.final-inner::before{
  content:"";position:absolute;right:-60px;top:-60px;width:260px;height:260px;
  border-radius:50%;border:2px dashed rgba(255,247,237,.28);
}
.final-inner h2{font-size:clamp(24px,3vw,34px);margin:0 0 10px;font-weight:900;line-height:1.25}
.final-inner p{margin:0;max-width:34em;color:rgba(255,247,237,.88);font-size:15.5px}
.final-inner .btn-primary{background:#FFF7ED;color:var(--brand-deep);box-shadow:0 14px 26px -16px rgba(0,0,0,.6)}
.final-inner .btn-primary:hover{background:#fff;color:var(--brand-deep)}
.final-inner .btn-ghost{border-color:rgba(255,247,237,.5);color:#FFF7ED}
.final-inner .btn-ghost:hover{border-color:#FFF7ED;color:#fff;background:rgba(255,247,237,.1)}

/* ---------- footer ---------- */
.footer{border-top:1px solid var(--line);background:var(--bg-soft)}
.footer-inner{
  max-width:1240px;margin:0 auto;padding:36px clamp(18px,5vw,56px) 40px;
  display:flex;flex-wrap:wrap;align-items:center;gap:14px 28px;
}
.footer-brand{display:flex;align-items:center;gap:9px;font-weight:800;font-size:16px}
.footer-desc{font-size:13.5px;color:var(--ink-3);margin:0;flex:1 1 280px}
.footer-nav{display:flex;flex-wrap:wrap;gap:8px 20px;font-size:14px;color:var(--ink-2)}
.footer-nav a:hover{color:var(--brand-deep)}
.copyright{width:100%;margin:8px 0 0;font-size:13px;color:var(--ink-3);border-top:1px dashed var(--line);padding-top:16px}

/* ---------- responsive ---------- */
@media (max-width:1024px){
  .subject-grid,.scene-grid{grid-template-columns:1fr 1fr}
  .hero{grid-template-columns:1fr;gap:40px}
  .hero-stage{min-height:360px}
  .embed-inner{grid-template-columns:1fr}
}
@media (max-width:768px){
  .topnav{display:none}
  .topbar{gap:12px}
  .brand{margin-right:auto}
  .hero{padding-top:32px}
  .hero-stage{min-height:420px}
  .card-a{top:5%;left:4%;width:56%}
  .card-b{top:33%;right:3%;width:62%}
  .card-c{bottom:14%;left:6%;width:60%}
  .stage-code{right:auto;left:6%;bottom:4%;font-size:10.5px;max-width:88%}
  .subject-grid,.scene-grid{grid-template-columns:1fr}
  .assure{gap:8px 16px;font-size:13px}
  .btn{width:100%}
  .cta-row{width:100%}
  .final-inner{flex-direction:column;align-items:flex-start}
  .final-inner .cta-row{width:100%}
}
@media (prefers-reduced-motion:reduce){
  *{transition:none!important;scroll-behavior:auto!important}
}