@font-face{font-family:'DM Sans';font-style:normal;font-weight:100 1000;font-display:swap;src:url('assets/dm-sans-latin.woff2') format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+2000-206F,U+2191,U+2193,U+2212}

:root{
  --ink:#0b1f3f;        /* 标题 · logo 近黑海军蓝 */
  --navy:#0a3569;       /* logo 深蓝 */
  --blue:#0d4d99;       /* 主行动色 · logo 宝蓝 */
  --blue-dark:#083b78;
  --tint:#d7e8f7;       /* logo 冰蓝 */
  --bg:#f5f8fc;
  --card:#ffffff;
  --line:#dfe8f3;
  --body:#3d4c66;
  --muted:#64748f;
  --max:1060px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--body);font:15px/1.75 'DM Sans','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif}
h1,h2,h3{color:var(--ink);line-height:1.35;margin:0}
img{max-width:100%}

/* ---------- nav ---------- */
.site-nav{position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;padding:14px clamp(20px,4vw,48px);background:rgba(255,255,255,.85);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand img{width:34px;height:34px}
.brand strong{font-size:19px;letter-spacing:.02em}
.brand em{font-style:normal;font-size:10px;letter-spacing:.18em;color:var(--muted);margin-top:3px}
.nav-actions{display:flex;align-items:center;gap:18px}
.nav-link{border:0;background:none;color:var(--body);font:14px inherit;cursor:pointer;padding:4px 2px}
.nav-link:hover{color:var(--blue)}
.nav-cta{background:var(--blue);color:#fff;text-decoration:none;font-size:14px;font-weight:600;padding:9px 20px;border-radius:9px;transition:.18s}
.nav-cta:hover{background:var(--blue-dark)}

/* ---------- hero ---------- */
.hero{max-width:var(--max);margin:0 auto;padding:clamp(48px,8vw,96px) 24px clamp(40px,6vw,72px);display:grid;grid-template-columns:1.25fr .75fr;gap:48px;align-items:center}
.eyebrow{font-size:13px;font-weight:600;letter-spacing:.06em;color:var(--blue);margin:0 0 18px}
h1{font-size:clamp(34px,4.6vw,52px);font-weight:800;letter-spacing:-.01em}
.hero-lead{font-size:16px;color:var(--muted);margin:22px 0 30px;max-width:520px}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap}
.button{display:inline-flex;align-items:center;justify-content:center;height:48px;padding:0 26px;border-radius:11px;font:600 15px inherit;text-decoration:none;cursor:pointer;transition:.18s;border:0}
.button.primary{background:var(--blue);color:#fff;box-shadow:0 6px 18px rgba(13,77,153,.22)}
.button.primary:hover{background:var(--blue-dark);transform:translateY(-1px)}
.button.ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.button.ghost:hover{border-color:var(--blue);color:var(--blue)}
.button.light{background:#fff;color:var(--blue);font-weight:700}
.button.light:hover{transform:translateY(-1px)}
.hero-trust{display:flex;gap:8px;flex-wrap:wrap;margin-top:30px}
.hero-trust span{font-size:12px;color:var(--navy);background:var(--tint);border-radius:99px;padding:6px 14px}
.hero-visual{display:grid;place-items:center;padding:34px;background:linear-gradient(160deg,#fff,#eaf2fb);border:1px solid var(--line);border-radius:24px;box-shadow:0 18px 50px rgba(10,53,105,.08)}
.hero-visual img{width:min(240px,60vw)}

/* ---------- sections ---------- */
.section{max-width:var(--max);margin:0 auto;padding:clamp(44px,6vw,76px) 24px}
.section-head{margin-bottom:36px}
.section-head span{display:inline-block;font-size:13px;font-weight:600;color:var(--blue);background:var(--tint);border-radius:99px;padding:5px 14px;margin-bottom:16px}
.section-head h2{font-size:clamp(25px,3.2vw,34px);font-weight:800}

.card-grid{display:grid;gap:16px}
.card-grid.three{grid-template-columns:repeat(3,1fr)}
.card-grid.two{grid-template-columns:repeat(2,1fr)}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:26px 24px;transition:.2s}
.card:hover{border-color:#bcd2ec;box-shadow:0 10px 28px rgba(10,53,105,.08);transform:translateY(-2px)}
.card b{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:10px;background:var(--tint);color:var(--navy);font-size:13px;margin-bottom:14px}
.card h3{font-size:17px;margin-bottom:8px}
.card p{margin:0;font-size:13.5px;color:var(--muted)}
.statement{margin:36px auto 0;text-align:center;font-size:17px;font-weight:600;color:var(--ink);line-height:1.9}

/* 人机分工 */
.division{display:grid;grid-template-columns:1fr auto 1fr;gap:20px;align-items:stretch}
.division-side{border-radius:16px;padding:28px 26px;border:1px solid var(--line)}
.division-side.ai{background:linear-gradient(165deg,#0d3f7d,var(--navy));border-color:transparent}
.division-side.ai h3,.division-side.ai li{color:#fff}
.division-side.ai .side-tag{background:rgba(255,255,255,.16);color:#cfe3f8}
.division-side.human{background:var(--card)}
.side-tag{display:inline-block;font-size:12px;font-weight:600;border-radius:99px;padding:4px 12px;background:var(--tint);color:var(--navy);margin-bottom:14px}
.division-side h3{font-size:18px;margin-bottom:12px}
.division-side ul{margin:0;padding-left:18px}
.division-side li{margin:7px 0;font-size:14px;color:var(--body)}
.division-arrow{align-self:center;font-size:22px;color:var(--blue);background:var(--tint);width:44px;height:44px;border-radius:50%;display:grid;place-items:center}
.manifesto{margin:36px 0 0;text-align:center;font-size:18px;font-weight:700;color:var(--ink)}

/* 隐私条 */
.privacy{margin-top:16px;background:linear-gradient(150deg,#0d2c58,var(--ink));border-radius:16px;padding:32px 30px;display:grid;grid-template-columns:1.3fr 1fr;gap:30px;align-items:center}
.privacy-copy h3{color:#fff;font-size:20px;margin-bottom:10px}
.privacy-copy p{margin:0;font-size:13.5px;color:#b9c9e2;line-height:1.8}
.privacy-chips{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.privacy-chips span{text-align:center;font-size:13px;color:#e7f0fb;border:1px solid rgba(215,232,247,.35);border-radius:10px;padding:11px 8px;background:rgba(255,255,255,.06)}

/* ---------- closing ---------- */
.closing{max-width:var(--max);margin:0 auto clamp(48px,6vw,80px);padding:clamp(44px,6vw,70px) 32px;text-align:center;background:linear-gradient(150deg,var(--navy),#083b78 55%,#0d4d99);border-radius:24px}
.closing-tag{margin:0 0 14px;font-size:13px;letter-spacing:.08em;color:#9fc0e8}
.closing h2{color:#fff;font-size:clamp(24px,3.4vw,34px);font-weight:800}
.closing-line{color:#cfe0f5;font-size:15px;margin:16px 0 28px}

/* ---------- footer ---------- */
footer{border-top:1px solid var(--line);padding:26px 24px 34px;text-align:center;font-size:12px;color:var(--muted)}
footer span{font-weight:700;color:var(--navy);letter-spacing:.06em}
footer p{margin:8px 0}
footer a{color:var(--muted)}

/* ---------- wechat modal ---------- */
.wechat-backdrop{position:fixed;inset:0;background:rgba(11,31,63,.45);backdrop-filter:blur(5px);opacity:0;visibility:hidden;transition:.22s;z-index:40}
.wechat-backdrop.open{opacity:1;visibility:visible}
.wechat-modal{position:fixed;z-index:41;left:50%;top:50%;width:min(calc(100% - 36px),360px);transform:translate(-50%,-46%) scale(.97);padding:32px 28px 26px;background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 30px 80px rgba(10,53,105,.25);text-align:center;opacity:0;visibility:hidden;transition:.22s}
.wechat-modal.open{opacity:1;visibility:visible;transform:translate(-50%,-50%) scale(1)}
.wechat-close{position:absolute;right:12px;top:8px;border:0;background:none;color:var(--muted);font-size:26px;cursor:pointer}
.wechat-label{font-size:10px;letter-spacing:.2em;color:var(--blue);font-weight:700}
.wechat-modal h2{font-size:21px;margin:8px 0 6px}
.wechat-modal p{font-size:12px;color:var(--muted);margin:0 0 16px}
.wechat-code{width:216px;height:216px;margin:0 auto 12px;padding:8px;background:#fff;border:1px solid var(--line);border-radius:12px}
.wechat-code img{display:block;width:100%;height:100%;object-fit:contain}
.wechat-modal small{color:var(--muted);font-size:11px}

/* ---------- reveal ---------- */
.reveal{opacity:0;transform:translateY(16px);transition:opacity .55s ease,transform .55s ease}
.reveal.visible{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* ---------- mobile ---------- */
@media(max-width:820px){
  .hero{grid-template-columns:1fr;gap:32px}
  .hero-visual{order:-1;padding:24px;justify-self:start}
  .hero-visual img{width:110px}
  .card-grid.three,.card-grid.two{grid-template-columns:1fr}
  .division{grid-template-columns:1fr}
  .division-arrow{transform:rotate(90deg);justify-self:center}
  .privacy{grid-template-columns:1fr;padding:26px 22px}
  .closing{margin-left:16px;margin-right:16px;border-radius:18px}
  .nav-link{display:none}
}