/* ========== 观止 GUANZHI Landing Page — Premium Dark Theme ========== */
:root {
  --bg: #08080c;
  --bg2: #0e0e16;
  --bg3: #16162a;
  --primary: #6c3ce9;
  --primary-light: #8b5cf6;
  --accent: #06b6d4;
  --accent-light: #22d3ee;
  --gold: #f59e0b;
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --glass: rgba(255,255,255,.04);
  --glass-border: rgba(255,255,255,.08);
  --radius: 16px;
  --transition: .35s cubic-bezier(.4,0,.2,1);
}

/* Reset */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:'Inter','Noto Sans SC','PingFang SC','Microsoft YaHei',sans-serif;
  background:var(--bg);color:var(--text);line-height:1.7;overflow-x:hidden}
a{color:inherit;text-decoration:none}
ul{list-style:none}
img{max-width:100%;display:block}

/* ── Utility ── */
.container{max-width:1200px;margin:0 auto;padding:0 24px}
.section{padding:120px 0}
.section-label{font-size:.75rem;letter-spacing:4px;text-transform:uppercase;color:var(--accent);margin-bottom:12px}
.section-title{font-size:clamp(2rem,4vw,3rem);font-weight:800;line-height:1.2;margin-bottom:20px;
  background:linear-gradient(135deg,var(--text) 40%,var(--primary-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.section-desc{font-size:1.1rem;color:var(--text-muted);max-width:640px}
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 36px;border-radius:50px;font-weight:600;
  font-size:1rem;cursor:pointer;border:none;transition:var(--transition)}
.btn-primary{background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;box-shadow:0 4px 24px rgba(108,60,233,.35)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 32px rgba(108,60,233,.5)}
.btn-outline{background:transparent;border:1px solid var(--glass-border);color:var(--text)}
.btn-outline:hover{border-color:var(--primary-light);background:var(--glass)}
.fade-in{opacity:0;transform:translateY(30px);transition:opacity .8s ease,transform .8s ease}
.fade-in.visible{opacity:1;transform:translateY(0)}

/* ── Navigation ── */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;padding:18px 0;transition:var(--transition)}
.nav.scrolled{background:rgba(10,10,15,.85);backdrop-filter:blur(20px);border-bottom:1px solid var(--glass-border);padding:12px 0}
.nav .container{display:flex;align-items:center;justify-content:space-between}
.nav-logo{font-size:1.5rem;font-weight:800;letter-spacing:2px;display:flex;align-items:center;gap:10px;
  background:linear-gradient(135deg,var(--primary-light),var(--accent-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.nav-logo .logo-svg{flex-shrink:0}
.nav-logo span{background:linear-gradient(135deg,var(--primary-light),var(--accent-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.nav-links{display:flex;gap:32px}
.nav-links a{font-size:.9rem;color:var(--text-muted);transition:var(--transition);position:relative}
.nav-links a:hover{color:var(--text)}
.nav-links a::after{content:'';position:absolute;bottom:-4px;left:0;width:0;height:2px;
  background:var(--primary-light);transition:var(--transition)}
.nav-links a:hover::after{width:100%}
.nav-cta{padding:10px 24px;font-size:.85rem}
.mobile-toggle{display:none;background:none;border:none;color:var(--text);font-size:1.5rem;cursor:pointer}

/* ── Hero ── */
.hero{min-height:100vh;display:flex;align-items:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;
  background:radial-gradient(ellipse 80% 60% at 50% 40%,rgba(108,60,233,.15),transparent 70%),
  radial-gradient(ellipse 60% 50% at 80% 20%,rgba(6,182,212,.1),transparent 60%)}
.hero-grid{position:absolute;inset:0;
  background-image:linear-gradient(var(--glass-border) 1px,transparent 1px),linear-gradient(90deg,var(--glass-border) 1px,transparent 1px);
  background-size:60px 60px;opacity:.3}
.hero .container{position:relative;z-index:1;text-align:center}
.hero-badge{display:inline-block;padding:6px 20px;border-radius:50px;font-size:.8rem;color:var(--accent-light);
  border:1px solid rgba(6,182,212,.3);background:rgba(6,182,212,.08);margin-bottom:28px}
.hero h1{font-size:clamp(2.8rem,6vw,4.5rem);font-weight:900;line-height:1.15;margin-bottom:24px;
  background:linear-gradient(135deg,#fff 30%,var(--primary-light) 70%,var(--accent-light));
  -webkit-background-clip:text;-webkit-text-fill-color:transparent}
.hero p{font-size:clamp(1.1rem,2vw,1.35rem);color:var(--text-muted);max-width:600px;margin:0 auto 40px}
.hero-buttons{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.hero-stats{display:flex;gap:48px;justify-content:center;margin-top:80px}
.hero-stat{text-align:center}
.hero-stat .num{font-size:2.5rem;font-weight:800;
  background:linear-gradient(135deg,var(--primary-light),var(--accent-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.hero-stat .label{font-size:.85rem;color:var(--text-dim);margin-top:4px}

/* ── Pain Points ── */
.pain{background:var(--bg2)}
.pain-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:24px;margin-top:48px}
.pain-card{background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius);padding:36px 28px;
  transition:var(--transition);position:relative;overflow:hidden}
.pain-card:hover{border-color:rgba(108,60,233,.3);transform:translateY(-4px)}
.pain-card::before{content:'';position:absolute;top:0;left:0;right:0;height:2px;
  background:linear-gradient(90deg,var(--primary),var(--accent));opacity:0;transition:var(--transition)}
.pain-card:hover::before{opacity:1}
.pain-icon{font-size:2rem;margin-bottom:16px}
.pain-card h3{font-size:1.15rem;font-weight:700;margin-bottom:10px}
.pain-card p{font-size:.9rem;color:var(--text-muted);line-height:1.6}

/* ── Pipeline ── */
.pipeline{margin-top:60px}
.pipeline-row{display:grid;grid-template-columns:repeat(6,1fr);gap:12px}
.pipe-step{text-align:center;position:relative;padding:16px 8px;background:var(--glass);border:1px solid var(--glass-border);
  border-radius:var(--radius);transition:var(--transition)}
.pipe-step:hover{border-color:var(--primary-light);transform:translateY(-4px);box-shadow:0 8px 32px rgba(108,60,233,.2)}
.pipe-step::after{content:'→';position:absolute;right:-14px;top:50%;transform:translateY(-50%);
  color:var(--primary-light);font-size:1.2rem;font-weight:700}
.pipe-step:last-child::after{display:none}
.pipe-icon{font-size:2rem;margin-bottom:10px}
.pipe-step h4{font-size:.85rem;font-weight:700;margin-bottom:6px}
.pipe-step p{font-size:.7rem;color:var(--text-muted);line-height:1.4}
.pipe-diff{margin-top:40px}
.diff-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:16px;margin-top:20px}
.diff-card{background:var(--glass);border:1px solid var(--glass-border);border-radius:12px;padding:24px;transition:var(--transition)}
.diff-card:hover{border-color:var(--accent)}
.diff-card h4{font-size:.95rem;font-weight:700;margin-bottom:8px;color:var(--accent-light)}
.diff-card p{font-size:.85rem;color:var(--text-muted)}

/* ── Demo Reel ── */
.demo{background:var(--bg2)}
.demo-tabs{display:flex;gap:12px;margin-top:32px;margin-bottom:32px}
.demo-tab{padding:10px 28px;border-radius:50px;font-size:.9rem;font-weight:600;cursor:pointer;
  border:1px solid var(--glass-border);background:transparent;color:var(--text-muted);transition:var(--transition)}
.demo-tab.active{background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;border-color:transparent;
  box-shadow:0 4px 20px rgba(108,60,233,.35)}
.demo-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:24px}
.demo-card{background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius);overflow:hidden;transition:var(--transition)}
.demo-card:hover{border-color:var(--primary-light);transform:translateY(-3px)}
.demo-video{width:100%;aspect-ratio:16/9;background:#000;display:flex;align-items:center;justify-content:center;
  position:relative;overflow:hidden}
.demo-video::before{content:'▶';font-size:3rem;color:rgba(255,255,255,.7);z-index:1}
.demo-video::after{content:'';position:absolute;inset:0;
  background:linear-gradient(135deg,rgba(108,60,233,.15),rgba(6,182,212,.1))}
.demo-info{padding:20px}
.demo-badge{display:inline-block;padding:3px 12px;border-radius:50px;font-size:.7rem;font-weight:700;margin-bottom:8px}
.demo-badge.standard{background:rgba(6,182,212,.15);color:var(--accent-light);border:1px solid rgba(6,182,212,.3)}
.demo-badge.premium{background:rgba(245,158,11,.12);color:var(--gold);border:1px solid rgba(245,158,11,.3)}
.demo-info h4{font-size:1rem;font-weight:700;margin-bottom:6px}
.demo-info p{font-size:.8rem;color:var(--text-muted)}

/* ── Pricing ── */
.pricing-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:24px;margin-top:48px}
.price-card{background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius);padding:40px 32px;
  text-align:center;transition:var(--transition);position:relative;overflow:hidden}
.price-card:hover{border-color:var(--primary-light);transform:translateY(-4px)}
.price-card.featured{border-color:var(--gold);box-shadow:0 0 40px rgba(245,158,11,.1)}
.price-card.featured::before{content:'推荐';position:absolute;top:16px;right:-28px;
  background:linear-gradient(135deg,var(--gold),#f97316);color:#000;font-size:.7rem;font-weight:800;
  padding:4px 36px;transform:rotate(45deg)}
.price-tier{font-size:.85rem;color:var(--text-muted);letter-spacing:2px;text-transform:uppercase;margin-bottom:12px}
.price-name{font-size:1.4rem;font-weight:800;margin-bottom:8px}
.price-amount{font-size:2.4rem;font-weight:900;margin-bottom:4px;
  background:linear-gradient(135deg,var(--primary-light),var(--accent-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.price-unit{font-size:.85rem;color:var(--text-dim);margin-bottom:24px}
.price-features{text-align:left;margin-bottom:32px}
.price-features li{padding:8px 0;font-size:.88rem;color:var(--text-muted);border-bottom:1px solid var(--glass-border);
  display:flex;align-items:center;gap:10px}
.price-features li::before{content:'✓';color:var(--accent-light);font-weight:700;font-size:.8rem}
.price-features li.highlight{color:var(--text);font-weight:600}
.price-features li.highlight::before{content:'★';color:var(--gold)}

/* ── Use Cases ── */
.cases-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:16px;margin-top:48px}
.case-card{background:var(--glass);border:1px solid var(--glass-border);border-radius:12px;padding:28px 20px;
  text-align:center;transition:var(--transition);cursor:default}
.case-card:hover{border-color:var(--primary-light);background:rgba(108,60,233,.06);transform:translateY(-3px)}
.case-icon{font-size:2.2rem;margin-bottom:12px}
.case-card h4{font-size:.95rem;font-weight:600;margin-bottom:6px}
.case-card p{font-size:.75rem;color:var(--text-dim)}

/* ── Advantages ── */
.adv-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(340px,1fr));gap:24px;margin-top:48px}
.adv-card{display:flex;gap:20px;background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius);padding:32px;transition:var(--transition)}
.adv-card:hover{border-color:rgba(6,182,212,.3)}
.adv-num{flex-shrink:0;width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;
  font-weight:800;font-size:1.1rem;background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff}
.adv-card h3{font-size:1.05rem;font-weight:700;margin-bottom:6px}
.adv-card p{font-size:.88rem;color:var(--text-muted)}

/* ── Contact / CTA ── */
.cta{background:var(--bg2);position:relative;overflow:hidden}
.cta::before{content:'';position:absolute;inset:0;
  background:radial-gradient(ellipse 70% 50% at 50% 80%,rgba(108,60,233,.12),transparent)}
.cta-inner{text-align:center;position:relative;z-index:1}
.cta-inner .section-title{max-width:none}
.contact-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:24px;margin-top:48px;max-width:800px;margin-left:auto;margin-right:auto}
.contact-card{background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius);padding:36px 24px;text-align:center;transition:var(--transition)}
.contact-card:hover{border-color:var(--primary-light)}
.contact-icon{font-size:2.4rem;margin-bottom:12px}
.contact-card h4{font-size:1rem;font-weight:600;margin-bottom:8px}
.contact-card p{font-size:.9rem;color:var(--text-muted);word-break:break-all}

/* ── Footer ── */
.footer{padding:40px 0;border-top:1px solid var(--glass-border);text-align:center}
.footer p{font-size:.8rem;color:var(--text-dim)}
.footer-logo{display:flex;align-items:center;justify-content:center;margin-bottom:12px;font-size:1rem;color:var(--text-muted)}

/* ── Glow Orbs (decorative) ── */
.orb{position:absolute;border-radius:50%;filter:blur(80px);pointer-events:none;opacity:.5}
.orb-1{width:400px;height:400px;background:var(--primary);top:-200px;right:-100px}
.orb-2{width:300px;height:300px;background:var(--accent);bottom:-150px;left:-100px}

/* ── Responsive ── */
@media(max-width:768px){
  .container{padding:0 16px}
  .nav-links{display:none}
  .mobile-toggle{display:block}
  .nav-cta{display:none}
  .hero{min-height:auto;padding:120px 0 80px}
  .hero h1{font-size:2rem;line-height:1.25}
  .hero p{font-size:1rem}
  .hero-badge{font-size:.7rem;padding:5px 14px}
  .hero-stats{flex-direction:column;gap:20px;margin-top:48px}
  .hero-stat .num{font-size:2rem}
  .section{padding:64px 0}
  .section-title{font-size:1.6rem}
  .section-desc{font-size:.95rem}
  .pain-grid{grid-template-columns:1fr;gap:16px}
  .pain-card{padding:24px 20px}
  .pipeline-row{grid-template-columns:repeat(2,1fr);gap:10px}
  .pipe-step::after{display:none}
  .pipe-step{padding:14px 8px}
  .pipe-step h4{font-size:.8rem}
  .pipe-step p{font-size:.65rem}
  .diff-grid{grid-template-columns:1fr}
  .demo-tabs{flex-wrap:wrap}
  .demo-tab{padding:8px 16px;font-size:.8rem}
  .demo-grid{grid-template-columns:1fr}
  .pricing-grid{grid-template-columns:1fr;gap:20px}
  .price-card{padding:32px 20px}
  .cases-grid{grid-template-columns:repeat(2,1fr);gap:12px}
  .case-card{padding:20px 12px}
  .case-icon{font-size:1.8rem;margin-bottom:8px}
  .case-card h4{font-size:.85rem}
  .case-card p{font-size:.7rem}
  .contact-grid{grid-template-columns:1fr;gap:16px}
  .contact-card{padding:24px 16px}
  .adv-grid{grid-template-columns:1fr}
  .orb-1{width:200px;height:200px;top:-100px;right:-60px}
  .orb-2{width:150px;height:150px;bottom:-80px;left:-50px}
}
@media(max-width:480px){
  .hero h1{font-size:1.7rem}
  .hero p{font-size:.9rem}
  .hero-buttons{flex-direction:column;align-items:stretch}
  .hero-buttons .btn{justify-content:center}
  .hero-stats{gap:16px}
  .hero-stat .num{font-size:1.7rem}
  .section-title{font-size:1.4rem}
  .pipeline-row{grid-template-columns:1fr 1fr}
  .pipe-icon{font-size:1.5rem}
  .pricing-grid{gap:16px}
  .price-amount{font-size:2rem}
  .cases-grid{grid-template-columns:repeat(2,1fr);gap:10px}
  .case-card{padding:16px 10px}
  .nav-logo svg{width:28px;height:28px}
  .nav-logo span{font-size:1.2rem}
}