:root{
  --bg:#ffffff;
  --text:#111111;
  --muted:#5d5d5d;
  --line:#e7e7e7;
  --soft:#f5f5f5;
  --soft-2:#fafafa;
  --black:#111111;
  --white:#ffffff;
  --shadow: 0 18px 50px rgba(0,0,0,.06);
  --radius: 24px;
  --radius-sm: 16px;
  --container: 1200px;
  --transition: .25s ease;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--text);
  background:
    radial-gradient(circle at 10% 10%, rgba(0,0,0,.04), transparent 24%),
    radial-gradient(circle at 90% 20%, rgba(0,0,0,.03), transparent 20%),
    linear-gradient(180deg, #fff 0%, #fff 100%);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  line-height:1.75;
  overflow-x:hidden;
}

body::before,
body::after{
  content:"";
  position:fixed;
  inset:auto;
  width:420px;
  height:420px;
  border-radius:50%;
  pointer-events:none;
  filter: blur(40px);
  opacity:.28;
  z-index:-1;
}
body::before{
  top:-120px;
  right:-140px;
  background:rgba(0,0,0,.06);
}
body::after{
  left:-160px;
  bottom:-120px;
  background:rgba(0,0,0,.04);
}

a{
  color:inherit;
  text-decoration:none;
}
img{
  display:block;
  max-width:100%;
}
button{
  font:inherit;
}
.container{
  width:min(var(--container), calc(100% - 32px));
  margin-inline:auto;
}
.section{
  padding:78px 0;
  position:relative;
}
.section-head{
  text-align:center;
  max-width:860px;
  margin:0 auto 34px;
}
.section-label{
  margin:0 0 10px;
  color:var(--muted);
  font-size:.92rem;
  letter-spacing:.18em;
  text-transform:uppercase;
}
.section-head h2{
  margin:0 0 10px;
  font-size:clamp(1.8rem, 2.6vw, 3rem);
  line-height:1.15;
}
.section-head p{
  margin:0;
  color:var(--muted);
}

.site-header{
  position:sticky;
  top:0;
  z-index:100;
  background:rgba(255,255,255,.82);
  backdrop-filter: blur(16px);
  border-bottom:1px solid rgba(0,0,0,.06);
}
.header-inner{
  min-height:76px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}
.brand{
  display:flex;
  align-items:center;
  gap:12px;
  font-weight:800;
  letter-spacing:.02em;
}
.brand-logo{
  width:42px;
  height:42px;
  border-radius:12px;
  object-fit:cover;
  border:1px solid var(--line);
  background:#fff;
}
.brand-text{
  font-size:1.08rem;
}

.nav{
  display:flex;
  align-items:center;
  gap:22px;
}
.nav a{
  color:#1a1a1a;
  font-size:.98rem;
  transition:color var(--transition), transform var(--transition), opacity var(--transition);
}
.nav a:hover{opacity:.72}
.nav .btn{margin-left:2px}

.menu-toggle{
  display:none;
  width:46px;
  height:46px;
  border:1px solid var(--line);
  background:#fff;
  border-radius:14px;
  cursor:pointer;
  align-items:center;
  justify-content:center;
  flex-direction:column;
  gap:4px;
  box-shadow:0 8px 24px rgba(0,0,0,.04);
}
.menu-toggle span{
  width:18px;
  height:2px;
  background:var(--black);
  border-radius:999px;
  display:block;
}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 18px;
  border-radius:999px;
  border:1px solid transparent;
  transition:transform var(--transition), background var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition);
  cursor:pointer;
  white-space:nowrap;
  font-weight:600;
}
.btn:hover{
  transform:translateY(-1px);
}
.btn-dark{
  background:var(--black);
  color:var(--white);
  box-shadow:0 12px 30px rgba(0,0,0,.16);
}
.btn-dark:hover{
  background:#000;
}
.btn-light{
  background:#fff;
  color:#111;
  border-color:var(--line);
}
.btn-light:hover{
  border-color:#cfcfcf;
  background:#fcfcfc;
}

.hero{
  padding-top:58px;
}
.hero-grid{
  display:grid;
  grid-template-columns:1.1fr .9fr;
  gap:32px;
  align-items:center;
}
.eyebrow{
  margin:0 0 12px;
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-size:.9rem;
  color:#444;
  letter-spacing:.12em;
  text-transform:uppercase;
}
.hero-copy h1{
  margin:0;
  font-size:clamp(2.4rem, 4vw, 4.8rem);
  line-height:1.05;
  letter-spacing:-.04em;
}
.hero-desc{
  margin:18px 0 0;
  max-width:62ch;
  color:var(--muted);
  font-size:1.05rem;
}
.hero-actions{
  margin-top:28px;
  display:flex;
  flex-wrap:wrap;
  gap:12px;
}
.hero-stats{
  margin-top:30px;
  display:grid;
  grid-template-columns:repeat(3, minmax(0, 1fr));
  gap:14px;
}
.stat-card{
  background:var(--soft);
  border:1px solid var(--line);
  border-radius:18px;
  padding:18px;
  min-height:96px;
  display:flex;
  flex-direction:column;
  justify-content:space-between;
}
.stat-card strong{
  font-size:1.6rem;
  letter-spacing:-.03em;
}
.stat-card span{
  color:var(--muted);
  font-size:.95rem;
}

.panel{
  background:linear-gradient(180deg, #fbfbfb 0%, #f4f4f4 100%);
  border:1px solid var(--line);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
}
.hero-panel{
  padding:18px;
}
.mockup-top{
  display:flex;
  gap:8px;
  padding:6px 2px 14px;
}
.mockup-top span{
  width:10px;
  height:10px;
  border-radius:50%;
  background:#d2d2d2;
}
.chat-preview{
  padding:8px 6px 6px;
}
.chat-row{
  display:flex;
  margin-bottom:14px;
}
.chat-row.user{justify-content:flex-end}
.chat-row.ai{justify-content:flex-start}
.chat-bubble{
  max-width:92%;
  padding:14px 16px;
  border-radius:18px;
  border:1px solid #e2e2e2;
  background:#fff;
  color:#1a1a1a;
  box-shadow:0 10px 24px rgba(0,0,0,.04);
}
.chat-row.user .chat-bubble{
  background:#111;
  color:#fff;
  border-color:#111;
}
.chat-tags{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin-top:18px;
}
.chat-tags span{
  padding:8px 12px;
  border:1px solid var(--line);
  border-radius:999px;
  background:#fff;
  color:#333;
  font-size:.92rem;
}

.grid{
  display:grid;
  gap:18px;
}
.cards-5{
  grid-template-columns:repeat(5, minmax(0, 1fr));
}
.cards-4{
  grid-template-columns:repeat(4, minmax(0, 1fr));
}
.cards-3{
  grid-template-columns:repeat(3, minmax(0, 1fr));
}
.card{
  background:var(--soft);
  border:1px solid var(--line);
  border-radius:22px;
  padding:22px;
  box-shadow:0 10px 28px rgba(0,0,0,.04);
  transition:transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.card:hover{
  transform:translateY(-3px);
  box-shadow:0 18px 36px rgba(0,0,0,.07);
  border-color:#d9d9d9;
}
.card h3{
  margin:0 0 8px;
  font-size:1.1rem;
}
.card-sub{
  margin:0 0 10px;
  color:var(--muted);
  font-size:.96rem;
}
.card p{
  margin:0;
  color:#2a2a2a;
}
.card ul{
  margin:12px 0 0;
  padding-left:18px;
  color:#2a2a2a;
}
.card li{
  margin:6px 0;
}

.feature-card .icon{
  width:46px;
  height:46px;
  display:grid;
  place-items:center;
  border-radius:14px;
  background:#111;
  color:#fff;
  font-weight:700;
  margin-bottom:14px;
  letter-spacing:.04em;
}
.prompt-card{
  min-height:220px;
}

.faq-list{
  display:grid;
  gap:14px;
  max-width:960px;
  margin:0 auto;
}
.faq-item{
  background:var(--soft);
  border:1px solid var(--line);
  border-radius:18px;
  overflow:hidden;
  box-shadow:0 10px 28px rgba(0,0,0,.04);
}
.faq-question{
  width:100%;
  text-align:left;
  border:none;
  background:transparent;
  padding:18px 20px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  cursor:pointer;
  color:#111;
  font-weight:700;
}
.faq-question span{
  width:30px;
  height:30px;
  display:grid;
  place-items:center;
  border-radius:50%;
  border:1px solid #d7d7d7;
  background:#fff;
  flex:0 0 auto;
  transition:transform var(--transition);
}
.faq-item.open .faq-question span{
  transform:rotate(45deg);
}
.faq-answer{
  max-height:0;
  overflow:hidden;
  padding:0 20px;
  color:var(--muted);
  transition:max-height .35s ease, padding .35s ease;
}
.faq-item.open .faq-answer{
  padding:0 20px 20px;
}

.cta-section{
  padding-top:28px;
}
.cta{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:22px;
  padding:28px;
}
.cta h2{
  margin:0 0 10px;
  font-size:clamp(1.5rem, 2.4vw, 2.4rem);
  line-height:1.15;
}
.cta p{
  margin:0;
  color:var(--muted);
}
.cta-actions{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
}

.site-footer{
  padding:24px 0 40px;
}
.footer-inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  padding-top:18px;
  border-top:1px solid var(--line);
  color:var(--muted);
  font-size:.95rem;
}
.footer-inner a{
  color:#111;
  font-weight:600;
}

/* Responsive */
@media (max-width: 1100px){
  .cards-5{
    grid-template-columns:repeat(2, minmax(0, 1fr));
  }
  .cards-4{
    grid-template-columns:repeat(2, minmax(0, 1fr));
  }
  .cards-3{
    grid-template-columns:repeat(2, minmax(0, 1fr));
  }
  .hero-grid{
    grid-template-columns:1fr;
  }
}

@media (max-width: 860px){
  .menu-toggle{
    display:inline-flex;
  }

  .nav{
    position:absolute;
    top:76px;
    left:0;
    right:0;
    display:grid;
    gap:12px;
    padding:18px 16px 20px;
    background:rgba(255,255,255,.98);
    border-bottom:1px solid var(--line);
    box-shadow:0 18px 40px rgba(0,0,0,.05);
    transform:translateY(-10px);
    opacity:0;
    pointer-events:none;
    transition:opacity var(--transition), transform var(--transition);
  }
  .nav.is-open{
    opacity:1;
    transform:translateY(0);
    pointer-events:auto;
  }
  .nav a{
    padding:10px 6px;
  }
  .nav .btn{
    width:100%;
    margin-left:0;
  }

  .hero-stats{
    grid-template-columns:1fr;
  }
  .cta{
    flex-direction:column;
    align-items:flex-start;
  }
  .footer-inner{
    flex-direction:column;
    align-items:flex-start;
  }
}

@media (max-width: 640px){
  .section{
    padding:60px 0;
  }
  .cards-5,
  .cards-4,
  .cards-3{
    grid-template-columns:1fr;
  }
  .hero{
    padding-top:42px;
  }
  .hero-copy h1{
    font-size:2.25rem;
  }
  .card,
  .hero-panel,
  .cta{
    border-radius:20px;
  }
}