:root{
  --red:#F5434D; --red-d:#D93640; --red-soft:#FF7A82;
  --ink:#23282E; --ink-2:#333A42; --ink-3:#767D87;
  --line:#E8EAED; --bg:#FFFFFF; --bg-alt:#F6F7F8;
  --green:#34C26B; --blue:#4C9AFF; --violet:#A78BFA;
  --radius:16px;
  --shadow:0 18px 50px rgba(35,40,46,.10);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:'Inter','PingFang SC','Microsoft YaHei',system-ui,-apple-system,sans-serif;color:var(--ink);background:var(--bg);line-height:1.6;-webkit-font-smoothing:antialiased}
.wrap{max-width:1120px;margin:0 auto;padding:0 24px}
a{color:inherit;text-decoration:none}

/* ---- topbar ---- */
.topbar{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.86);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.topbar-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:16px}
.brand-mark{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border-radius:9px;color:#fff;background:linear-gradient(135deg,var(--red),var(--red-d));box-shadow:0 6px 16px rgba(245,67,77,.28)}
.nav{display:flex;gap:26px;font-size:14px;color:var(--ink-3);font-weight:500}
.nav a:hover{color:var(--red)}

/* ---- buttons ---- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;font-weight:600;border-radius:12px;transition:.18s}
.btn-primary{background:linear-gradient(135deg,var(--red),var(--red-d));color:#fff;box-shadow:0 10px 24px rgba(245,67,77,.30)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 30px rgba(245,67,77,.38)}
.btn-sm{height:38px;padding:0 18px;font-size:13px}
.btn-lg{height:54px;padding:0 30px;font-size:16px}
.btn-xl{height:64px;padding:0 40px;font-size:18px}

/* ---- hero ---- */
.hero{background:radial-gradient(1000px 600px at 85% -10%,rgba(245,67,77,.07),transparent),radial-gradient(800px 500px at -10% 10%,rgba(76,154,255,.06),transparent);padding:76px 0 90px;overflow:hidden}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center}
.eyebrow{display:inline-block;font-size:12.5px;font-weight:600;letter-spacing:.06em;color:var(--red);background:rgba(245,67,77,.08);border:1px solid rgba(245,67,77,.2);padding:6px 14px;border-radius:999px;margin-bottom:22px}
h1{font-size:46px;line-height:1.18;letter-spacing:-.015em}
.lead{margin-top:20px;font-size:17px;color:var(--ink-3);max-width:540px}
.hl{color:var(--red)}
.hero-cta{display:flex;align-items:center;gap:18px;margin-top:32px;flex-wrap:wrap}
.btn-note{font-size:13px;color:var(--ink-3)}
.hero-trust{list-style:none;margin-top:26px;display:flex;flex-direction:column;gap:8px;font-size:14px;color:var(--ink-2)}
.tick{color:var(--green);font-weight:700}

/* ---- hero visual ---- */
.hero-visual{position:relative}
.chat-card{background:#fff;border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow);padding:18px 20px 16px}
.chat-head{display:flex;align-items:center;gap:8px;padding-bottom:12px;border-bottom:1px solid var(--line)}
.u{width:22px;height:22px;border-radius:6px;display:inline-flex;align-items:center;justify-content:center;font-size:11px;color:#fff;font-weight:700}
.chat-title{font-size:12.5px;color:var(--ink-3);margin-left:6px;font-weight:500}
.chat-q{font-size:14.5px;font-weight:600;margin:16px 0 12px;background:var(--bg-alt);padding:12px 14px;border-radius:12px}
.chat-a{font-size:14.5px;color:var(--ink-2)}
.cite{display:inline-flex;align-items:center;gap:7px;margin-top:14px;font-size:12.5px;color:var(--ink-3);background:#fff;border:1px solid var(--line);padding:6px 11px;border-radius:8px}
.cite-dot{width:8px;height:8px;border-radius:50%;background:var(--green)}
.status-row{display:flex;gap:8px;margin-top:16px;flex-wrap:wrap;align-items:center}
.sta{font-size:11.5px;font-weight:600;padding:4px 10px;border-radius:999px;background:var(--bg-alt);color:var(--ink-3)}
.sta[data-t="ok"]{background:rgba(52,194,107,.12);color:#1d9e57}
.score{margin-left:auto;font-size:12px;font-weight:700;color:var(--violet)}
.flow-line{position:absolute;left:-18px;right:-18px;top:-14px;bottom:-14px;border-radius:26px;background:linear-gradient(135deg,rgba(245,67,77,.10),rgba(167,139,250,.10));filter:blur(6px);z-index:-1}

/* ---- section base ---- */
.section{padding:84px 0}
.section-alt{background:var(--bg-alt)}
.sec-title{font-size:32px;letter-spacing:-.01em;text-align:center}
.sec-sub{text-align:center;color:var(--ink-3);margin-top:10px;font-size:16px}

/* ---- features ---- */
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:44px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 22px;transition:.18s}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:transparent}
.card-icon{font-size:26px;width:52px;height:52px;display:flex;align-items:center;justify-content:center;border-radius:13px;background:color-mix(in srgb,var(--ic) 12%,#fff);border:1px solid color-mix(in srgb,var(--ic) 30%,transparent);margin-bottom:16px}
.card h3{font-size:17px;margin-bottom:8px}
.card p{font-size:13.5px;color:var(--ink-3)}

/* ---- pipeline ---- */
.pipeline{display:grid;grid-template-columns:repeat(5,1fr);gap:14px;margin-top:44px;align-items:start}
.pipe-node{background:#fff;border:1px solid var(--line);border-radius:14px;padding:20px 16px;text-align:left}
.pipe-num{width:30px;height:30px;border-radius:9px;background:linear-gradient(135deg,var(--red),var(--red-d));color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;font-size:14px;margin-bottom:12px}
.pipe-node h4{font-size:15px;margin-bottom:6px}
.pipe-node p{font-size:12.5px;color:var(--ink-3)}
.pipe-arrow{display:flex;align-items:center;justify-content:center;color:var(--red-soft);font-size:18px;padding-top:30px}

/* ---- secure ---- */
.secure-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:44px}
.secure-card{background:linear-gradient(180deg,#fff,#fbfcfd);border:1px solid var(--line);border-radius:var(--radius);padding:30px 26px;text-align:center}
.secure-icon{font-size:30px;margin-bottom:14px}
.secure-card h4{font-size:17px;margin-bottom:8px}
.secure-card p{font-size:14px;color:var(--ink-3)}

/* ---- download ---- */
.section-download{padding:0 0 96px}
.download-box{background:radial-gradient(800px 300px at 50% -40%,rgba(245,67,77,.14),transparent),linear-gradient(135deg,var(--ink),#1a1e23);border-radius:28px;padding:64px 48px;text-align:center;color:#fff;box-shadow:0 30px 70px rgba(35,40,46,.35)}
.download-box h2{font-size:34px;letter-spacing:-.01em}
.dl-sub{color:rgba(255,255,255,.7);margin-top:12px;font-size:15px}
.dl-cta{margin-top:30px;display:flex;flex-direction:column;align-items:center;gap:16px}
.download-box .btn-xl{background:linear-gradient(135deg,var(--red),var(--red-d));box-shadow:0 16px 40px rgba(245,67,77,.45)}
.download-box .btn-xl:hover{transform:translateY(-3px)}
.dl-meta{display:flex;flex-direction:column;gap:4px;font-size:13px;color:rgba(255,255,255,.6)}
.dl-steps{display:flex;gap:14px;margin-top:36px;justify-content:center;flex-wrap:wrap}
.s{background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.12);padding:12px 18px;border-radius:12px;font-size:13.5px}
.s span{display:inline-flex;width:22px;height:22px;border-radius:50%;background:var(--red);color:#fff;font-weight:700;align-items:center;justify-content:center;margin-right:8px;font-size:12px}

/* ---- footer ---- */
.footer{border-top:1px solid var(--line);padding:28px 0}
.footer-inner{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px}
.footer-brand{display:flex;align-items:center;gap:9px;font-weight:700}
.footer-brand .brand-mark{width:28px;height:28px;border-radius:7px;font-size:16px}
.footer-meta{font-size:13px;color:var(--ink-3)}

/* ---- responsive ---- */
@media (max-width:960px){
  .hero-grid{grid-template-columns:1fr}
  .nav{display:none}
  h1{font-size:36px}
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .pipeline{grid-template-columns:1fr;gap:10px}
  .pipe-arrow{transform:rotate(90deg);padding:4px}
  .secure-grid{grid-template-columns:1fr}
}
@media (max-width:560px){
  .grid-4{grid-template-columns:1fr}
  .hero{padding:48px 0 60px}
  .btn-xl{height:56px;padding:0 26px;font-size:16px}
  .download-box{padding:44px 24px}
}