:root{
  --brand:#0075ff; --brand-dark:#0057c4; --ink:#0c1a2b; --muted:#5b6b7c;
  --bg:#ffffff; --soft:#f4f8ff; --light:#eef4ff; --line:#e2ebf6; --radius:16px;
  --shadow:0 12px 30px rgba(12,60,140,.08); --max:1180px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:-apple-system,"PingFang SC","Microsoft YaHei",Segoe UI,sans-serif;color:var(--ink);background:var(--bg);line-height:1.7;overflow-x:hidden}
img,svg,video{max-width:100%;height:auto;display:block}
a{color:var(--brand);text-decoration:none;transition:.2s}
a:hover{color:var(--brand-dark)}
.container{max-width:var(--max);margin:0 auto;padding:0 20px}
.skip-link{position:absolute;left:-999px}
.skip-link:focus{left:16px;top:16px;background:#fff;padding:8px 14px;z-index:99;border-radius:8px}

/* 兜底：AOS 未加载时也保证内容可见 */
[data-aos] { opacity: 1 !important; transform: none !important; }



/* buttons */
.main-btn{display:inline-flex;align-items:center;gap:8px;background:linear-gradient(135deg,var(--brand),var(--brand-dark));color:#fff;padding:12px 24px;border-radius:40px;font-weight:600;box-shadow:0 8px 20px rgba(0,117,255,.28)}
.main-btn:hover{color:#fff;transform:translateY(-2px)}
.secondary-btn{display:inline-flex;align-items:center;gap:8px;background:#fff;color:var(--brand);border:1.5px solid var(--brand);padding:11px 22px;border-radius:40px;font-weight:600}
.secondary-btn:hover{background:var(--light)}

/* header */
.site-header{position:sticky;top:0;z-index:40;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.header-inner{max-width:var(--max);margin:0 auto;padding:12px 20px;display:flex;align-items:center;gap:24px}
.site-logo img{width:160px;height:auto}
.nav-core{display:flex;gap:22px;margin-left:auto;flex-wrap:wrap}
.nav-core a{color:var(--ink);font-weight:500;padding:6px 2px;position:relative}
.nav-core a.active,.nav-core a:hover{color:var(--brand)}
.nav-core a.active::after{content:"";position:absolute;left:0;right:0;bottom:-4px;height:2px;background:var(--brand);border-radius:2px}
.header-actions{display:flex;align-items:center;gap:14px}
.menu-button{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:6px}
.menu-button span{width:24px;height:2px;background:var(--ink);border-radius:2px}

/* drawer */
.drawer-overlay{position:fixed;inset:0;background:rgba(8,20,40,.45);z-index:50;opacity:0;transition:.22s}
.drawer-overlay.is-open{opacity:1}
.site-drawer{position:fixed;top:0;right:0;height:100%;width:300px;max-width:85%;background:#fff;z-index:60;transform:translateX(105%);transition:.24s;display:flex;flex-direction:column;padding:20px;box-shadow:-10px 0 30px rgba(0,0,0,.12)}
.site-drawer.is-open{transform:translateX(0)}
.drawer-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}
.drawer-close{background:none;border:0;font-size:28px;cursor:pointer;color:var(--muted)}
.drawer-nav{display:flex;flex-direction:column;gap:4px}
.drawer-nav a{color:var(--ink);padding:12px 10px;border-radius:10px;font-weight:500}
.drawer-nav a:hover{background:var(--light)}
.drawer-download{margin-top:auto;justify-content:center}
body.drawer-open{overflow:hidden}

/* hero */
.hero{background:linear-gradient(160deg,#eaf3ff 0%,#f7fbff 60%,#fff 100%);padding:70px 0 60px}
.hero-grid,.split{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center}
.split.reverse .split-media{order:2}
.eyebrow{display:inline-block;color:var(--brand);font-weight:700;font-size:.85rem;letter-spacing:.5px;background:var(--light);padding:5px 14px;border-radius:30px;margin-bottom:14px}
h1{font-size:2.6rem;line-height:1.2;margin:.2em 0}
h2{font-size:1.8rem;margin:.2em 0}
h3{font-size:1.2rem;margin:.4em 0}
.lead{font-size:1.15rem;color:var(--muted)}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin:22px 0}
.hero-badges{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px}
.hero-badge{background:#fff;border:1px solid var(--line);border-radius:30px;padding:8px 16px;font-size:.88rem;color:var(--muted);display:flex;align-items:center;gap:6px}
.hero-badge i{color:var(--brand)}
.hero-visual img{border-radius:24px;box-shadow:var(--shadow);margin:0 auto}

/* page-hero */
.page-hero{background:linear-gradient(160deg,#eaf3ff,#f7fbff);padding:56px 0;text-align:center}
.page-hero h1{font-size:2.2rem}

/* sections */
.section{padding:64px 0}
.section-light{background:var(--light)}
.section-soft{background:var(--soft)}
.section-heading{text-align:center;max-width:720px;margin:0 auto 42px}

/* info grid */
.info-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.info-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow);transition:.25s;text-align:left}
.info-card:hover{transform:translateY(-6px)}
.info-card strong{display:block;font-size:1.1rem;margin:10px 0 6px}
.info-card p{color:var(--muted);margin:0;font-size:.95rem}
.icon{font-size:1.9rem;color:var(--brand)}

/* category grid */
.category-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.category-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow);transition:.25s}
.category-card:hover{transform:translateY(-6px);border-color:var(--brand)}
.category-card p{color:var(--muted);font-size:.95rem}
.category-card a{font-weight:600}

/* split */
.split-copy p{color:var(--muted)}
.split-media img{border-radius:var(--radius);box-shadow:var(--shadow)}

/* step grid */
.step-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.step-card{position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px 24px;box-shadow:var(--shadow);transition:.25s}
.step-card:hover{transform:translateY(-6px)}
.step-num{position:absolute;top:-14px;left:24px;width:34px;height:34px;background:var(--brand);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700}
.step-card p{color:var(--muted);font-size:.94rem}

/* download */
.download-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.download-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:34px 26px;box-shadow:var(--shadow);text-align:center;transition:.25s}
.download-card:hover{transform:translateY(-6px)}
.download-card .icon{font-size:2.6rem}
.download-card p{color:var(--muted);font-size:.94rem;min-height:44px}

/* review */
.review-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.review-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}
.review-card p{color:var(--ink)}
.review-card strong{color:var(--muted);font-weight:600;font-size:.9rem}

/* faq */
.faq-list{max-width:840px;margin:0 auto;display:flex;flex-direction:column;gap:14px}
.faq-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:6px 20px;box-shadow:var(--shadow)}
.faq-card summary{cursor:pointer;font-weight:600;padding:14px 0;list-style:none;display:flex;align-items:center;gap:10px}
.faq-card summary i{color:var(--brand)}
.faq-card summary::-webkit-details-marker{display:none}
.faq-card[open] summary{color:var(--brand)}
.faq-card p{color:var(--muted);padding:0 0 16px;margin:0}

/* notice */
.notice{border-radius:12px;padding:18px 22px}
.notice.warning{background:#fff7e6;border:1px solid #ffe0a3;color:#7a5200}

/* cta */
.cta-band{background:linear-gradient(135deg,var(--brand),var(--brand-dark));color:#fff;border-radius:22px;padding:38px 40px;display:flex;align-items:center;justify-content:space-between;gap:24px;flex-wrap:wrap}
.cta-band h2,.cta-band p{color:#fff;margin:.2em 0}

/* footer */
.site-footer{background:#0c1a2b;color:#c7d3e2;padding:52px 0 24px}
.footer-inner{max-width:var(--max);margin:0 auto;padding:0 20px;display:grid;grid-template-columns:1.4fr 2fr;gap:40px}
.footer-brand p{color:#8fa2b8;font-size:.92rem}
.footer-social{display:flex;gap:14px;margin-top:14px}
.footer-social a{width:38px;height:38px;border-radius:50%;background:rgba(255,255,255,.08);display:flex;align-items:center;justify-content:center;color:#c7d3e2}
.footer-social a:hover{background:var(--brand);color:#fff}
.footer-links{display:grid;grid-template-columns:repeat(2,1fr);gap:24px}
.footer-links h2{font-size:1rem;color:#fff;margin:0 0 12px}
.footer-links a{display:block;color:#8fa2b8;padding:5px 0;font-size:.92rem}
.footer-links a:hover{color:#fff}
.footer-risk{max-width:var(--max);margin:36px auto 0;padding:18px 20px;border-top:1px solid rgba(255,255,255,.1);color:#8fa2b8;font-size:.86rem}
.footer-bottom{text-align:center;color:#6d7f95;font-size:.85rem;margin-top:18px}

/* ============ 响应式适配 ============ */
/* 平板 / 中屏：≤ 960px */
@media (max-width:960px){
  .info-grid,.category-grid,.step-grid{grid-template-columns:repeat(2,1fr)}
  .download-grid,.review-grid{grid-template-columns:1fr}
  .hero-grid,.split{grid-template-columns:1fr;gap:32px}
  .split.reverse .split-media{order:0}
  .footer-inner{grid-template-columns:1fr}
  h1{font-size:2.2rem}
  h2{font-size:1.55rem}
  .section{padding:48px 0}
  .hero{padding:50px 0 40px}
}
/* 手机：≤ 720px */
@media (max-width:720px){
  .nav-core,.header-download{display:none}
  .menu-button{display:flex}
  .info-grid,.category-grid,.step-grid{grid-template-columns:1fr}
  h1{font-size:1.9rem}
  h2{font-size:1.4rem}
  .lead{font-size:1rem}
  .hero-actions{flex-direction:column;align-items:stretch}
  .hero-actions .main-btn,.hero-actions .secondary-btn{justify-content:center;width:100%}
  .cta-band{flex-direction:column;text-align:center;padding:30px 22px}
  .cta-band .hero-actions{width:100%}
  .container{padding:0 16px}
  .section{padding:40px 0}
  .page-hero{padding:44px 0}
  .hero-badge{font-size:.8rem;padding:6px 12px}
}
/* 小屏手机：≤ 420px */
@media (max-width:420px){
  h1{font-size:1.65rem}
  .info-card,.category-card,.download-card{padding:20px}
  .faq-card{padding:4px 14px}
  .site-drawer{width:88%}
}