:root{
  --bg:#f5f5f7;
  --surface:#ffffff;
  --ink:#1d1d1f;
  --ink-2:#6e6e73;
  --ink-3:#86868b;
  --blue:#0066cc;
  --blue-hover:#0077ed;
  --blue-soft:#e8f1fb;
  --line:#e8e8ed;
  --radius:20px;
  --radius-sm:14px;
  --shadow:0 8px 28px rgba(0,0,0,.07);
  --shadow-sm:0 2px 10px rgba(0,0,0,.05);
}
*{margin:0;padding:0;box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","PingFang SC","Helvetica Neue","Microsoft YaHei",sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}

/* 顶部通知栏 */
.notice{
  background:var(--ink);color:#fff;text-align:center;
  font-size:13px;padding:9px 16px;letter-spacing:.5px;
}
.notice b{color:#6ab7ff;font-weight:600}
.notice .dot{color:#6ab7ff;margin:0 8px}

/* 导航 */
.nav-wrap{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.82);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid var(--line);
}
.nav{
  max-width:1120px;margin:0 auto;padding:14px 20px;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
}
.logo{display:flex;align-items:center;gap:10px;font-size:19px;font-weight:700;letter-spacing:.3px}
.logo .mark{
  width:30px;height:30px;border-radius:9px;flex:0 0 auto;
  background:linear-gradient(135deg,#0a84ff,#0066cc);
  color:#fff;font-size:15px;font-weight:800;
  display:flex;align-items:center;justify-content:center;
}
.logo .mark span{transform:translateY(-1px)}
.main-nav{display:flex;align-items:center;gap:6px}
.main-nav a{
  padding:8px 14px;border-radius:10px;font-size:15px;color:var(--ink-2);
  transition:.15s;
}
.main-nav a:hover{color:var(--ink);background:rgba(0,0,0,.04)}
.main-nav a.nav-buy{
  background:var(--blue);color:#fff;font-weight:600;margin-left:6px;
}
.main-nav a.nav-buy:hover{background:var(--blue-hover)}
.nav-toggle{
  display:none;background:none;border:0;font-size:24px;color:var(--ink);
  cursor:pointer;line-height:1;padding:4px;
}

.container{max-width:1120px;margin:0 auto;padding:0 20px}

/* 首屏 */
.hero{
  position:relative;overflow:hidden;
  padding:64px 0 56px;
}
.hero::before{
  content:"";position:absolute;inset:0;
  background:
    radial-gradient(720px 420px at 18% -10%,rgba(0,102,204,.12),transparent 60%),
    radial-gradient(640px 400px at 85% 10%,rgba(10,132,255,.10),transparent 60%);
  pointer-events:none;
}
.hero .container{position:relative}
.hero-tag{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--blue-soft);color:var(--blue);
  font-size:13px;font-weight:600;padding:6px 14px;border-radius:999px;margin-bottom:20px;
}
.hero h1{font-size:42px;font-weight:800;letter-spacing:-.5px;line-height:1.2;margin-bottom:16px}
.hero h1 .hl{color:var(--blue)}
.hero p.lead{font-size:17px;color:var(--ink-2);max-width:640px;margin-bottom:28px}
.hero-cta{display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  background:var(--blue);color:#fff;font-size:16px;font-weight:600;
  padding:14px 32px;border-radius:999px;transition:.15s;cursor:pointer;border:0;
}
.btn:hover{background:var(--blue-hover)}
.btn.ghost{background:#fff;color:var(--ink);box-shadow:var(--shadow-sm);border:1px solid var(--line)}
.btn.ghost:hover{background:#fafafa}
.hero-meta{
  display:flex;gap:22px;flex-wrap:wrap;margin-top:30px;padding-top:24px;
  border-top:1px solid var(--line);
}
.hero-meta .item{display:flex;align-items:center;gap:9px;font-size:14px;color:var(--ink-2)}
.hero-meta .item .ic{
  width:34px;height:34px;border-radius:10px;background:#fff;box-shadow:var(--shadow-sm);
  display:flex;align-items:center;justify-content:center;font-size:17px;
}

/* 区块通用 */
.section{padding:52px 0}
.section-head{text-align:center;margin-bottom:34px}
.section-head h2{font-size:30px;font-weight:800;letter-spacing:-.3px}
.section-head h2 .hl{color:var(--blue)}
.section-head p{color:var(--ink-2);font-size:15px;margin-top:10px}

/* 商品卡片 */
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.card{
  background:var(--surface);border-radius:var(--radius);
  box-shadow:var(--shadow-sm);padding:24px;position:relative;
  transition:transform .18s,box-shadow .18s;border:1px solid var(--line);
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.card .flag{
  font-size:34px;width:58px;height:58px;border-radius:16px;
  background:var(--bg);display:flex;align-items:center;justify-content:center;margin-bottom:16px;
}
.card h3{font-size:18px;font-weight:700;margin-bottom:6px}
.card .desc{font-size:14px;color:var(--ink-2);min-height:42px;margin-bottom:14px}
.card .tags{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:18px}
.tag{font-size:12px;color:var(--blue);background:var(--blue-soft);padding:3px 10px;border-radius:999px;font-weight:500}
.price-row{display:flex;align-items:baseline;justify-content:space-between;padding-top:16px;border-top:1px solid var(--line)}
.price{font-size:24px;font-weight:800;color:var(--ink)}
.price .cur{font-size:14px;font-weight:600;color:var(--ink-2);margin-right:2px}
.buy{
  display:inline-flex;align-items:center;background:var(--blue);color:#fff;
  font-size:14px;font-weight:600;padding:9px 20px;border-radius:999px;transition:.15s;
}
.buy:hover{background:var(--blue-hover)}
.buy.mini{padding:7px 16px;font-size:13px}

/* 信任面板 */
.features{background:var(--surface);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.feat-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.feat{text-align:center;padding:8px 6px}
.feat .ic{
  width:52px;height:52px;margin:0 auto 14px;border-radius:15px;
  background:var(--blue-soft);display:flex;align-items:center;justify-content:center;font-size:24px;
}
.feat h3{font-size:16px;font-weight:700;margin-bottom:6px}
.feat p{font-size:13px;color:var(--ink-2)}

/* 购买流程 */
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;counter-reset:step}
.step{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px 22px;position:relative;
}
.step .n{
  width:34px;height:34px;border-radius:50%;background:var(--blue);color:#fff;
  font-size:15px;font-weight:700;display:flex;align-items:center;justify-content:center;margin-bottom:14px;
}
.step h3{font-size:16px;font-weight:700;margin-bottom:8px}
.step p{font-size:13px;color:var(--ink-2)}

/* 文章 */
.articles{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
.article{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:30px;
}
.article .cat{font-size:12px;color:var(--blue);font-weight:600;letter-spacing:.5px;margin-bottom:10px}
.article h3{font-size:19px;font-weight:700;line-height:1.45;margin-bottom:12px}
.article p{font-size:14px;color:var(--ink-2);margin-bottom:10px}
.article p:last-child{margin-bottom:0}

/* FAQ */
.faq{max-width:760px;margin:0 auto}
.faq details{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);
  padding:0 22px;margin-bottom:12px;overflow:hidden;
}
.faq summary{
  cursor:pointer;list-style:none;font-size:16px;font-weight:600;
  padding:18px 0;display:flex;align-items:center;justify-content:space-between;gap:14px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:22px;color:var(--blue);font-weight:500;flex:0 0 auto}
.faq details[open] summary::after{content:"−"}
.faq details p{font-size:14px;color:var(--ink-2);padding:0 0 18px}

/* 底部 CTA */
.cta{
  background:linear-gradient(135deg,#0a2f55,#0052a8);color:#fff;text-align:center;
  padding:60px 20px;
}
.cta h2{font-size:30px;font-weight:800;margin-bottom:12px;letter-spacing:-.3px}
.cta p{font-size:15px;color:rgba(255,255,255,.78);max-width:560px;margin:0 auto 26px}
.cta .btn{background:#fff;color:var(--blue);font-size:16px;padding:15px 40px}
.cta .btn:hover{background:#eef4fb}

/* 页脚 */
footer{background:var(--surface);border-top:1px solid var(--line);padding:44px 0 32px}
.foot-grid{display:flex;flex-wrap:wrap;gap:28px;justify-content:space-between;margin-bottom:28px}
.foot-col h4{font-size:14px;font-weight:700;margin-bottom:12px}
.foot-col p,.foot-col a{font-size:13px;color:var(--ink-2);line-height:2}
.foot-col a:hover{color:var(--blue)}
.foot-note{font-size:12px;color:var(--ink-3);line-height:1.9;border-top:1px solid var(--line);padding-top:20px}
.hot-searches{font-size:12px;color:var(--ink-3);margin-top:14px;line-height:2}
.copy{font-size:12px;color:var(--ink-3);margin-top:16px;text-align:center}

/* 移动端 */
@media(max-width:900px){
  .grid{grid-template-columns:repeat(2,1fr)}
  .feat-grid{grid-template-columns:repeat(2,1fr)}
  .steps{grid-template-columns:repeat(2,1fr)}
  .hero h1{font-size:32px}
}
@media(max-width:640px){
  .nav-toggle{display:block}
  .main-nav{
    display:none;position:absolute;top:100%;left:0;right:0;
    background:#fff;border-bottom:1px solid var(--line);
    flex-direction:column;align-items:stretch;padding:10px 16px 16px;gap:4px;
  }
  .main-nav.open{display:flex}
  .main-nav a{padding:12px 14px;font-size:16px}
  .main-nav a.nav-buy{margin-left:0;text-align:center}
  .grid{grid-template-columns:1fr}
  .articles{grid-template-columns:1fr}
  .hero{padding:44px 0 40px}
  .hero h1{font-size:29px}
  .hero p.lead{font-size:15px}
  .steps{grid-template-columns:1fr 1fr}
  .section{padding:40px 0}
  .section-head h2{font-size:24px}
}

/* 文章页 */
.breadcrumb{font-size:13px;color:var(--ink-3);margin:20px 0;display:flex;flex-wrap:wrap;align-items:center;gap:6px}
.breadcrumb a{color:var(--ink-2)}
.breadcrumb a:hover{color:var(--blue)}
.breadcrumb .sep{color:var(--ink-3)}
.article-page{padding:20px 0 56px}
.article-page .narrow{max-width:780px}
.article-head .cat{font-size:13px;color:var(--blue);font-weight:600;letter-spacing:.5px;margin-bottom:10px}
.article-head h1{font-size:30px;font-weight:800;letter-spacing:-.3px;line-height:1.3;margin-bottom:14px}
.article-meta{font-size:13px;color:var(--ink-3)}
.article-body{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:38px}
.article-body p{font-size:15px;line-height:1.9;color:#333;margin-bottom:18px}
.article-body h2{font-size:21px;font-weight:700;margin:28px 0 14px;padding-left:14px;border-left:4px solid var(--blue)}
.article-body ul{margin:0 0 18px 22px;font-size:15px;line-height:1.9;color:#333}
.article-body ul li{margin-bottom:6px}
.article-body .buy-cta{text-align:center;margin-top:30px;padding-top:28px;border-top:1px solid var(--line)}
.related{margin-top:40px}
.related h2{font-size:22px;font-weight:800;margin-bottom:20px}
.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.related-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:20px;transition:.15s;display:block}
.related-card:hover{border-color:var(--blue);box-shadow:var(--shadow-sm)}
.related-card .t{font-size:15px;font-weight:600;line-height:1.5;margin-bottom:8px;color:var(--ink)}
.related-card .d{font-size:13px;color:var(--ink-2);line-height:1.6}
.article h3 a{color:var(--ink);transition:.15s}
.article h3 a:hover{color:var(--blue)}
.more{display:inline-block;margin-top:14px;font-size:14px;font-weight:600;color:var(--blue)}
.more:hover{text-decoration:underline}

@media(max-width:640px){
  .article-head h1{font-size:24px}
  .article-body{padding:24px 20px}
  .related-grid{grid-template-columns:1fr}
}

/* 移动端底部悬浮购买栏 */
.mobile-cta{display:none;position:fixed;left:0;right:0;bottom:0;z-index:60;background:rgba(255,255,255,.96);-webkit-backdrop-filter:saturate(180%) blur(20px);backdrop-filter:saturate(180%) blur(20px);border-top:1px solid var(--line);padding:10px 16px;box-shadow:0 -4px 20px rgba(0,0,0,.07)}
.mobile-cta .inner{display:flex;align-items:center;gap:12px;max-width:640px;margin:0 auto}
.mobile-cta .info{flex:1;min-width:0}
.mobile-cta .info .t{font-size:13px;font-weight:600;color:var(--ink)}
.mobile-cta .info .d{font-size:11px;color:var(--ink-2);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.mobile-cta .btn{padding:11px 22px;font-size:15px;flex:0 0 auto;white-space:nowrap}

@media(max-width:640px){
  .mobile-cta{display:block}
  body:has(.mobile-cta){padding-bottom:74px}
}