:root{
  --bg:#0c0e13;
  --bg2:#10131b;
  --panel:#141824;
  --panel2:#1a1f2e;
  --line:rgba(255,255,255,.09);
  --line2:rgba(255,255,255,.16);
  --text:#e9ebf2;
  --muted:#9aa1b4;
  --muted2:#6b7284;
  --accent:#f5a623;
  --accent2:#ffc966;
  --green:#3ecf8e;
  --red:#f0555b;
  --radius:14px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--text);
  font-family:var(--font);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--accent2);text-decoration:none}
code{
  background:rgba(255,255,255,.07);
  border:1px solid var(--line);
  border-radius:6px;
  padding:1px 6px;
  font-size:.88em;
  font-family:"SFMono-Regular",Consolas,"Liberation Mono",monospace;
}

/* ---------- nav ---------- */
.nav{
  position:sticky;top:0;z-index:50;
  background:rgba(12,14,19,.78);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.nav-inner{
  max-width:1120px;margin:0 auto;padding:12px 24px;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
}
.brand{display:flex;align-items:center;gap:10px;color:var(--text);font-weight:600}
.brand-mark{
  width:34px;height:34px;border-radius:10px;
  display:grid;place-items:center;
  background:linear-gradient(135deg,var(--accent),#d97f0a);
  color:#1a1206;font-weight:800;font-size:14px;
}
.nav-links{display:flex;gap:20px;font-size:14px;color:var(--muted)}
.nav-links a{color:var(--muted);transition:color .15s}
.nav-links a:hover{color:var(--text)}

/* ---------- hero ---------- */
.hero{
  max-width:960px;margin:0 auto;padding:88px 24px 64px;
  text-align:center;
}
.hero-badge{
  display:inline-flex;align-items:center;gap:8px;
  border:1px solid var(--line2);border-radius:999px;
  padding:6px 14px;font-size:13px;color:var(--muted);
  background:rgba(255,255,255,.03);
  margin-bottom:24px;
}
.dot{width:8px;height:8px;border-radius:50%;background:var(--green);display:inline-block}
.dot.green{background:var(--green)}
.hero h1{
  font-size:clamp(32px,5.4vw,54px);
  line-height:1.25;font-weight:800;letter-spacing:.5px;
}
.grad{
  background:linear-gradient(100deg,var(--accent2),var(--accent));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero-sub{max-width:660px;margin:22px auto 0;color:var(--muted);font-size:17px}
.hero-sub strong{color:var(--text)}
.hero-meta{
  margin-top:26px;display:flex;justify-content:center;flex-wrap:wrap;gap:10px;
}
.hero-meta span{
  border:1px solid var(--line);background:var(--panel);
  border-radius:10px;padding:7px 14px;font-size:13.5px;color:var(--muted);
}
.hero-actions{margin-top:34px;display:flex;justify-content:center;gap:14px;flex-wrap:wrap}

/* ---------- buttons ---------- */
.btn{
  display:inline-block;border-radius:12px;padding:13px 26px;
  font-size:15px;font-weight:600;cursor:pointer;
  border:1px solid transparent;transition:transform .12s,box-shadow .12s;
}
.btn:active{transform:scale(.98)}
.btn-primary{
  background:linear-gradient(135deg,var(--accent),#e18b0c);
  color:#1a1206;box-shadow:0 8px 28px rgba(245,166,35,.28);
}
.btn-primary:hover{box-shadow:0 10px 34px rgba(245,166,35,.4)}
.btn-ghost{background:transparent;border-color:var(--line2);color:var(--text)}
.btn-ghost:hover{background:rgba(255,255,255,.05)}
.btn-sm{padding:9px 18px;font-size:13.5px}

/* ---------- sections ---------- */
.section{
  max-width:1120px;margin:0 auto;padding:72px 24px;
  border-top:1px solid var(--line);
}
.section-head{text-align:center;margin-bottom:44px}
.kicker{
  font-size:12px;letter-spacing:2.5px;text-transform:uppercase;color:var(--accent);
  font-weight:700;
}
.section-head h2{font-size:clamp(26px,3.6vw,36px);font-weight:800;margin-top:8px}
.demo-note{
  max-width:680px;margin:16px auto 0;color:var(--muted);font-size:14px;
}
.demo-note strong{color:var(--text)}

/* ---------- demo ---------- */
.demo-wrap{
  display:grid;grid-template-columns:300px 1fr 1fr;
  gap:18px;align-items:start;
}
.demo-inputs{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px;
}
.demo-inputs h3{font-size:15px;margin-bottom:14px}
.chip-list{display:flex;flex-direction:column;gap:8px}
.chip{
  text-align:left;border:1px solid var(--line);background:var(--panel2);
  color:var(--text);border-radius:10px;padding:11px 14px;font-size:14px;
  cursor:pointer;transition:border-color .15s,background .15s;
  font-family:var(--font);
}
.chip:hover{border-color:var(--line2)}
.chip.active{border-color:var(--accent);background:rgba(245,166,35,.1)}
.input-tip{margin-top:14px;font-size:12.5px;color:var(--muted);min-height:38px}
.demo-ctrls{margin-top:14px;display:flex;gap:10px;flex-wrap:wrap}

.chat-col{display:flex;flex-direction:column}
.chat{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;display:flex;flex-direction:column;
}
.chat-head{
  display:flex;align-items:center;gap:12px;
  padding:13px 16px;border-bottom:1px solid var(--line);
  background:var(--panel2);
}
.chat-avatar{
  width:36px;height:36px;border-radius:50%;
  background:linear-gradient(135deg,var(--accent),#d97f0a);
  color:#1a1206;font-weight:800;display:grid;place-items:center;font-size:13px;
}
.chat-title{font-size:14.5px;font-weight:700}
.chat-status{font-size:12px;color:var(--muted);display:flex;align-items:center;gap:6px}
.demo-tag{
  margin-left:auto;border:1px solid var(--accent);color:var(--accent2);
  font-size:11px;font-weight:800;letter-spacing:1px;
  border-radius:6px;padding:3px 8px;
}
.chat-body{
  padding:16px;min-height:330px;max-height:430px;overflow-y:auto;
  display:flex;flex-direction:column;gap:12px;
}
.msg{
  max-width:88%;border-radius:14px;padding:11px 14px;font-size:14px;
  animation:msgIn .28s ease;
  white-space:pre-line;
}
@keyframes msgIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.msg.bot{
  background:var(--panel2);border:1px solid var(--line);border-bottom-left-radius:4px;
}
.msg.user{
  align-self:flex-end;background:linear-gradient(135deg,var(--accent),#e18b0c);
  color:#1a1206;border-bottom-right-radius:4px;font-weight:500;
}
.msg .step{display:flex;align-items:center;gap:8px;padding:3px 0}
.msg .step .ok{color:var(--green);font-weight:800}
.msg .step .pending{color:var(--muted2)}
.typing-dots{display:inline-flex;gap:4px;padding:4px 2px}
.typing-dots i{width:6px;height:6px;border-radius:50%;background:var(--muted);animation:blink 1s infinite}
.typing-dots i:nth-child(2){animation-delay:.15s}
.typing-dots i:nth-child(3){animation-delay:.3s}
@keyframes blink{0%,100%{opacity:.25}50%{opacity:1}}

/* ---------- output panel ---------- */
.output-panel{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  min-height:400px;overflow:hidden;
}
.output-empty{
  height:400px;display:flex;flex-direction:column;align-items:center;justify-content:center;
  gap:8px;color:var(--muted);text-align:center;padding:24px;
}
.empty-icon{font-size:40px;opacity:.5}
.muted{color:var(--muted2);font-size:12.5px}
.hidden{display:none!important}
.output-ready{padding:0}
.output-head{
  display:flex;align-items:center;gap:10px;
  padding:14px 16px;border-bottom:1px solid var(--line);background:var(--panel2);
}
.output-title{font-size:14.5px;font-weight:700}
.output-sub{font-size:12px;color:var(--muted)}
.tabs{display:flex;border-bottom:1px solid var(--line);overflow-x:auto}
.tab{
  flex:1;white-space:nowrap;padding:11px 10px;font-size:12.5px;font-weight:600;
  background:transparent;border:none;border-bottom:2px solid transparent;
  color:var(--muted);cursor:pointer;font-family:var(--font);
}
.tab.active{color:var(--accent2);border-bottom-color:var(--accent)}
.tab-body{padding:16px;max-height:430px;overflow-y:auto;font-size:13.5px}
.tab-body h4{font-size:14px;margin:10px 0 6px;color:var(--accent2)}
.tab-body h4:first-child{margin-top:0}
.tab-body p{margin:6px 0}
.tab-body blockquote{
  border-left:3px solid var(--accent);padding:6px 12px;margin:10px 0;
  background:rgba(245,166,35,.06);border-radius:0 8px 8px 0;color:var(--text);
}
.tab-body table{width:100%;border-collapse:collapse;margin:10px 0;font-size:12px}
.tab-body th,.tab-body td{border:1px solid var(--line);padding:6px 8px;text-align:left}
.tab-body th{background:var(--panel2);white-space:nowrap}
.tab-body .demo-note-inline{
  font-size:12px;color:var(--muted2);border:1px dashed var(--line2);
  border-radius:8px;padding:8px 10px;margin-bottom:10px;
}

/* ---------- cards ---------- */
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.card{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  padding:22px;
  transition:transform .15s,border-color .15s;
}
.card:hover{transform:translateY(-3px);border-color:var(--line2)}
.card-num{
  font-size:13px;font-weight:800;color:var(--accent);letter-spacing:1px;margin-bottom:8px;
}
.card h3{font-size:17px;margin-bottom:8px}
.card p{font-size:13.5px;color:var(--muted)}
.extras{margin-top:22px;display:flex;flex-direction:column;gap:12px}
.extra{
  display:flex;gap:14px;align-items:flex-start;
  background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:14px 18px;
  font-size:14px;color:var(--muted);
}
.extra strong{color:var(--text)}
.extra-icon{
  width:30px;height:30px;flex:none;border-radius:8px;
  display:grid;place-items:center;
  background:rgba(245,166,35,.12);color:var(--accent2);font-weight:800;
}

/* ---------- rules ---------- */
.rules-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.rule-block{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  padding:22px;
}
.rule-block h3{font-size:16px;margin-bottom:14px}
.rule-block.wide{grid-column:1/-1}
.tbl{width:100%;border-collapse:collapse;font-size:13.5px}
.tbl th,.tbl td{border-bottom:1px solid var(--line);padding:9px 6px;text-align:left}
.tbl th{color:var(--muted);font-weight:600;font-size:12.5px}
.note{font-size:12.5px;color:var(--muted);margin-top:12px;padding:10px 12px;background:rgba(255,255,255,.03);border-radius:8px}
.checklist{margin:4px 0 0 4px;display:flex;flex-direction:column;gap:8px;font-size:13.5px;color:var(--muted)}
.checklist li{margin-left:20px}
.checklist b{color:var(--text)}

/* ---------- boundaries ---------- */
.bounds-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.bound-card{
  border-radius:var(--radius);padding:24px;
}
.bound-card.no{background:rgba(240,85,91,.06);border:1px solid rgba(240,85,91,.28)}
.bound-card.human{background:rgba(245,166,35,.06);border:1px solid rgba(245,166,35,.28)}
.bound-card h3{font-size:16px;margin-bottom:12px}
.bound-card ul{list-style:none;display:flex;flex-direction:column;gap:8px;font-size:13.5px;color:var(--muted)}
.bound-card li{padding-left:18px;position:relative}
.bound-card li::before{position:absolute;left:0;content:"·";font-weight:800}
.bound-card.no li::before{color:var(--red)}
.bound-card.human li::before{color:var(--accent)}

/* ---------- evidence ---------- */
.evidence-grid{display:grid;grid-template-columns:1.3fr 1fr;gap:24px;align-items:start}
.timeline{display:flex;flex-direction:column;gap:0}
.tl-item{
  position:relative;padding:0 0 18px 26px;
}
.tl-item::before{
  content:"";position:absolute;left:5px;top:8px;bottom:-2px;width:1px;background:var(--line2);
}
.tl-item:last-child::before{display:none}
.tl-item::after{
  content:"";position:absolute;left:0;top:7px;width:11px;height:11px;border-radius:50%;
  background:var(--accent);box-shadow:0 0 0 3px rgba(245,166,35,.18);
}
.tl-time{font-size:12px;color:var(--accent2);font-weight:700;font-family:monospace}
.tl-body{font-size:13.5px;color:var(--muted);margin-top:2px}
.tl-body b{color:var(--text)}
.stats{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.stat{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px 18px;text-align:center;
}
.stat-num{
  font-size:clamp(26px,3.2vw,38px);font-weight:800;
  background:linear-gradient(100deg,var(--accent2),var(--accent));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.stat-num .unit{font-size:.45em;font-weight:700;color:var(--muted);-webkit-text-fill-color:var(--muted);margin-left:3px}
.stat-label{font-size:12px;color:var(--muted);margin-top:6px}

/* ---------- faq ---------- */
.faq{max-width:760px;margin:0 auto;display:flex;flex-direction:column;gap:10px}
.faq details{
  background:var(--panel);border:1px solid var(--line);border-radius:12px;
  padding:4px 18px;
}
.faq summary{
  cursor:pointer;padding:13px 0;font-size:15px;font-weight:600;list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:12px;
}
.faq summary::after{content:"+";color:var(--accent);font-size:18px;font-weight:700}
.faq details[open] summary::after{content:"−"}
.faq p{padding:0 0 14px;color:var(--muted);font-size:14px}

/* ---------- footer ---------- */
.footer{
  border-top:1px solid var(--line);padding:40px 24px;text-align:center;
  color:var(--muted);font-size:13.5px;
}
.footer strong{color:var(--text)}

/* ---------- responsive ---------- */
@media(max-width:1024px){
  .demo-wrap{grid-template-columns:1fr}
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .evidence-grid{grid-template-columns:1fr}
}
@media(max-width:720px){
  .nav-links{display:none}
  .grid-4,.grid-3,.rules-grid,.bounds-grid{grid-template-columns:1fr}
  .section{padding:56px 18px}
  .hero{padding:64px 18px 48px}
  .stats{grid-template-columns:1fr 1fr}
}