/* ============================================================
   前端样式：轻量、零依赖、统一设计系统（性能优先）
   ============================================================ */
:root{
  --indigo:#4f46e5; --indigo-d:#4338ca; --blue:#2563eb; --blue-d:#1d4ed8;
  --ink:#0f172a; --muted:#64748b; --line:#e6e9f0; --line-soft:#eef1f6;
  --surface:#ffffff; --page:#f6f8fb; --dark:#0f172a; --dark-2:#1e293b;
  --radius:14px; --radius-lg:20px;
  --shadow-sm:0 1px 2px rgba(15,23,42,.06);
  --shadow:0 1px 3px rgba(15,23,42,.05),0 10px 30px rgba(15,23,42,.06);
  --shadow-lg:0 16px 40px rgba(15,23,42,.14);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",Helvetica,Arial,sans-serif;
  color:var(--ink);background:var(--page);line-height:1.65;font-size:16px;-webkit-font-smoothing:antialiased}
.container{max-width:1120px;margin:0 auto;padding:0 20px}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto;display:block}
h1{font-size:2.1rem;line-height:1.18;margin:.6em 0 .35em;letter-spacing:-.02em}
h2{font-size:1.45rem;margin:1em 0 .5em;letter-spacing:-.01em}
p{margin:.6em 0}
.muted{color:var(--muted);font-size:.92rem}

/* ---------------- 按钮 ---------------- */
.btn{display:inline-block;background:var(--blue);color:#fff;padding:11px 20px;border-radius:10px;
  border:0;cursor:pointer;font-size:1rem;font-weight:600;transition:transform .12s,background .15s,box-shadow .15s;
  box-shadow:var(--shadow-sm)}
.btn:hover{background:var(--blue-d);text-decoration:none;transform:translateY(-1px)}
.btn-primary{background:var(--blue)}
.btn-lg{padding:14px 28px;font-size:1.05rem}
.btn-sm{padding:7px 14px;font-size:.85rem}
.btn-light{background:#fff;color:var(--ink)}
.btn-light:hover{background:#eef2ff;color:var(--indigo-d)}
.btn-outline-light{background:transparent;color:#fff;border:1.5px solid rgba(255,255,255,.55)}
.btn-outline-light:hover{background:rgba(255,255,255,.14);color:#fff;text-decoration:none}

/* ---------------- 顶部导航 ---------------- */
.site-header{background:linear-gradient(180deg,#0f172a,#111c34);box-shadow:0 2px 14px rgba(15,23,42,.18);position:sticky;top:0;z-index:20}
.nav{display:flex;align-items:center;justify-content:space-between;padding:14px 20px;gap:14px}
.brand{color:#fff;font-weight:800;font-size:1.12rem;letter-spacing:-.01em;display:inline-flex;align-items:center;gap:8px}
.brand:hover{text-decoration:none;color:#fff}
.nav-links{display:flex;gap:6px;list-style:none;margin:0;padding:0;align-items:center}
.nav-links a{color:#cbd5e1;padding:8px 12px;border-radius:8px;font-size:.95rem;font-weight:500}
.nav-links a:hover{color:#fff;background:rgba(255,255,255,.08);text-decoration:none}
.nav-dropdown{position:relative}
.nav-dropdown-toggle{background:none;border:0;color:#cbd5e1;font:inherit;cursor:pointer;padding:8px 12px;border-radius:8px;display:inline-flex;align-items:center;gap:4px;line-height:1.2;font-size:.95rem;font-weight:500}
.nav-dropdown-toggle:hover{color:#fff;background:rgba(255,255,255,.08)}
.nav-dropdown .caret{font-size:.7em;opacity:.7}
.nav-dropdown-menu{position:absolute;top:100%;left:0;min-width:200px;background:var(--dark);color:#cbd5e1;border:1px solid #1e293b;border-radius:12px;box-shadow:var(--shadow-lg);padding:6px;list-style:none;margin:6px 0 0;display:none;z-index:50}
.nav-dropdown:hover .nav-dropdown-menu,.nav-dropdown:focus-within .nav-dropdown-menu{display:block}
.nav-dropdown-menu li{margin:0}
.nav-dropdown-menu a{display:block;padding:9px 12px;border-radius:8px;color:#cbd5e1;white-space:nowrap}
.nav-dropdown-menu a:hover{background:#334155;color:#fff;text-decoration:none}

/* ---------------- 语言切换 ---------------- */
.lang-switch{margin-left:10px}
.lang-switch select{
  appearance:none;-webkit-appearance:none;background:rgba(255,255,255,.08);color:#e2e8f0;
  border:1px solid rgba(255,255,255,.25);border-radius:9px;padding:7px 30px 7px 12px;font-size:.85rem;
  cursor:pointer;font-family:inherit;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'><path d='M1 1l4 4 4-4' stroke='%23cbd5e1' stroke-width='1.5' fill='none' stroke-linecap='round'/></svg>");
  background-repeat:no-repeat;background-position:right 10px center;
}
.lang-switch select:hover{background-color:rgba(255,255,255,.16);color:#fff}
.lang-switch select:focus{outline:2px solid #60a5fa;outline-offset:1px}
.lang-switch select option{color:var(--ink);background:#fff}
.visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}

/* ---------------- Hero（渐变卡片） ---------------- */
.hero{position:relative;background:linear-gradient(135deg,var(--indigo),var(--blue));color:#fff;border-radius:var(--radius-lg);
  padding:58px 30px;margin:26px 0 6px;text-align:center;overflow:hidden;box-shadow:0 22px 55px rgba(79,70,229,.28)}
.hero::before{content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(700px 360px at 82% -15%,rgba(255,255,255,.20),transparent 60%),
             radial-gradient(520px 280px at 8% 120%,rgba(255,255,255,.14),transparent 60%)}
.hero .container,.hero>*{position:relative}
.hero-badge{display:inline-flex;align-items:center;gap:7px;background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.28);
  color:#fff;font-size:.82rem;font-weight:600;padding:6px 15px;border-radius:999px;margin-bottom:20px;letter-spacing:.01em}
.hero h1{color:#fff;font-size:2.7rem;line-height:1.1;margin:.15em 0 .35em;letter-spacing:-.025em}
.hero .lead{color:rgba(255,255,255,.92);font-size:1.16rem;max-width:680px;margin:0 auto 28px}
.hero-cta{display:flex;gap:13px;justify-content:center;flex-wrap:wrap}
.hero-cta .btn{box-shadow:0 10px 24px rgba(15,23,42,.22)}
.hero-stats{display:flex;gap:14px 40px;justify-content:center;flex-wrap:wrap;margin-top:36px;
  border-top:1px solid rgba(255,255,255,.18);padding-top:26px}
.hero-stats div{font-size:.9rem;color:rgba(255,255,255,.9);font-weight:500}
.hero-stats b{display:block;font-size:1.5rem;font-weight:800;color:#fff;letter-spacing:-.01em;margin-bottom:2px}

/* ---------------- 区块标题 ---------------- */
.section-title{font-size:1.55rem;font-weight:750;margin:38px 0 18px;letter-spacing:-.02em}
.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;margin:38px 0 18px;flex-wrap:wrap}
.section-head .section-title{margin:0}
.section-link{color:var(--blue);font-weight:600;font-size:.95rem;white-space:nowrap}
.section-link:hover{text-decoration:underline}

/* ---------------- 网格 / 卡片 ---------------- */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:22px}
.features .grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}

.feature{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;
  box-shadow:var(--shadow);transition:transform .18s,box-shadow .18s,border-color .18s}
.feature:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg);border-color:#dbe2f0}
.feature-icon{width:48px;height:48px;border-radius:13px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,#eef2ff,#e0e7ff);color:var(--indigo);margin-bottom:16px}
.feature-icon svg{width:26px;height:26px}
.feature h3{font-size:1.12rem;margin:.2em 0 .4em}
.feature p{color:var(--muted);font-size:.95rem;margin:0}

.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
  display:flex;flex-direction:column;box-shadow:var(--shadow);transition:transform .18s,box-shadow .18s,border-color .18s}
.card:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg);border-color:#dbe2f0}
.card-img{width:100%;aspect-ratio:16/10;object-fit:cover;background:#eef2f7}
.card h3{font-size:1.06rem;margin:14px 16px 6px;line-height:1.35}
.card .excerpt{margin:0 16px;color:var(--muted);font-size:.9rem;flex:1;line-height:1.55}
.card .price{margin:12px 16px 0;font-weight:800;font-size:1.1rem;color:var(--ink)}
.card-foot{display:flex;align-items:center;justify-content:space-between;padding:14px 16px}
.card a.btn{margin:14px 16px 16px;align-self:flex-start}

/* 分类徽标 */
.card-cat,.product-cat{display:inline-block;font-size:.72rem;font-weight:700;letter-spacing:.03em;text-transform:uppercase;
  color:var(--indigo);background:#eef2ff;border:1px solid #e0e7ff;border-radius:999px;padding:3px 11px}
.card-cat{margin:14px 16px 0}
.product-cat{margin:10px 0 14px}

/* ---------------- 商品列表页 ---------------- */
.page-head{text-align:center;padding:40px 0 6px}
.page-head h1{font-size:2.1rem;margin:.2em 0 .25em}
.page-head .muted{margin:0 auto;max-width:560px}

/* 分类筛选条 */
.cat-filter{display:flex;flex-wrap:wrap;gap:9px;justify-content:center;margin:18px 0 26px}
.cat-filter a{padding:8px 16px;border:1px solid var(--line);border-radius:999px;color:#475569;font-size:.9rem;font-weight:500;transition:all .15s;background:#fff}
.cat-filter a:hover{text-decoration:none;border-color:#94a3b8;color:var(--ink)}
.cat-filter a.active{background:var(--ink);color:#fff;border-color:var(--ink)}

/* ---------------- 结账 / 成功 / 通用页 ---------------- */
.checkout,.success-page{padding:46px 0;display:flex;flex-direction:column;align-items:center}
.checkout>h1,.success-page>h1{text-align:center}
.checkout{justify-content:center}
.checkout-product{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px 26px;
  text-align:center;margin:8px 0 22px;box-shadow:var(--shadow);width:100%;max-width:480px}
.checkout-product h2{margin:.2em 0;font-size:1.25rem}
.checkout-product .price{font-weight:800;font-size:1.4rem;color:var(--ink);margin:6px 0 0}
.checkout-product .price .muted{font-size:.8rem;font-weight:500}
.form{display:flex;flex-direction:column;gap:12px;width:100%;max-width:480px;margin:0 auto}
.form label{font-weight:600;font-size:.92rem}
.form input,.form textarea,.form select{padding:12px 13px;border:1px solid var(--line);border-radius:10px;font-size:1rem;font-family:inherit;background:#fff;transition:border-color .15s,box-shadow .15s}
.form input:focus,.form textarea:focus,.form select:focus{outline:0;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.15)}
.form textarea{resize:vertical}
.form .btn{margin-top:4px}

/* ---------------- 结账：支付方式选择 ---------------- */
.pay-methods{border:0;margin:2px 0 0;padding:0}
.pay-methods legend{font-weight:700;font-size:.95rem;padding:0;margin-bottom:8px;color:var(--ink)}
.pay-method{display:flex;align-items:center;gap:12px;padding:13px 14px;border:1.5px solid var(--line);
  border-radius:12px;cursor:pointer;background:#fff;transition:border-color .15s,box-shadow .15s,background .15s;margin-bottom:8px}
.pay-method:hover{border-color:var(--blue)}
.pay-method.is-selected{border-color:var(--blue);background:#f5f8ff;box-shadow:0 0 0 3px rgba(37,99,235,.12)}
.pay-method input[type=radio]{accent-color:var(--blue);width:18px;height:18px;margin:0;flex:0 0 auto}
.pay-method .pm-icon{font-size:1.4rem;line-height:1;flex:0 0 auto}
.pay-method .pm-body{display:flex;flex-direction:column;gap:1px}
.pay-method .pm-title{font-weight:700;font-size:.98rem;color:var(--ink)}
.pay-method .pm-sub{font-size:.82rem;color:var(--muted);font-weight:400}
.crypto-coins{margin:0 0 2px;font-size:.82rem}
#pay-note{margin:2px 0 0}
.msg{padding:11px 14px;border-radius:10px;font-size:.92rem}
.msg.ok{background:#dcfce7;color:#166534}
.msg.err{background:#fee2e2;color:#991b1b}
.captcha-row{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.captcha-img{height:50px;width:150px;border:1px solid var(--line);border-radius:8px;cursor:pointer;background:#f1f5f9}

.pagination{display:flex;gap:8px;margin:32px 0;flex-wrap:wrap;justify-content:center}
.pagination a{padding:8px 13px;border:1px solid var(--line);border-radius:9px;background:#fff;color:var(--ink)}
.pagination a:hover{text-decoration:none;border-color:#94a3b8}
.pagination a.active{background:var(--blue);color:#fff;border-color:var(--blue)}

/* ---------------- 商品详情 ---------------- */
.product-detail{display:grid;grid-template-columns:1fr 1fr;gap:36px;padding:34px 0;align-items:start}
.product-media img{border-radius:var(--radius);border:1px solid var(--line);box-shadow:var(--shadow);width:100%}
.product-info .price{font-size:1.7rem;font-weight:800;margin:12px 0 18px;color:var(--ink)}
.product-info .amount{color:var(--ink)}
.product-info .btn{margin-top:6px}
.rich{margin-top:10px;grid-column:1/-1;max-width:780px;margin-left:auto;margin-right:auto}
.rich h2,.rich h3{margin-top:1.3em}
.rich ul{padding-left:1.25em}
.rich li{margin:.3em 0}

/* ---------------- 法律 / 隐私页 ---------------- */
.rich.legal{max-width:840px;margin:0 auto}
.rich.legal h2{font-size:1.25rem;margin-top:1.6em;border-bottom:1px solid var(--line);padding-bottom:.3em}

/* ---------------- 末屏 CTA 收束带 ---------------- */
.cta-band{background:linear-gradient(135deg,var(--dark),var(--dark-2));color:#fff;border-radius:var(--radius-lg);
  padding:46px 30px;margin:46px 0 14px;text-align:center;box-shadow:var(--shadow-lg)}
.cta-band h2{color:#fff;font-size:1.7rem;margin:.1em 0 .35em;letter-spacing:-.02em}
.cta-band p{color:rgba(255,255,255,.85);max-width:560px;margin:0 auto 22px;font-size:1.04rem}

/* ---------------- 页脚 ---------------- */
.site-footer{background:var(--dark);color:#94a3b8;margin-top:54px;padding:34px 0;font-size:.9rem}
.site-footer .container{display:flex;flex-direction:column;gap:6px;align-items:center;text-align:center}
.site-footer .muted{color:#64748b}
.site-footer .footer-links{margin-top:8px}
.site-footer .footer-links a{color:#cbd5e1;text-decoration:underline}
.site-footer .footer-links a:hover{color:#fff}

.center{text-align:center;padding:90px 0}

/* ---------------- 用户系统（登录 / 注册 / 账户中心） ---------------- */
.auth-page{padding:46px 0;display:flex;flex-direction:column;align-items:center}
.auth-page>h1{text-align:center;margin-bottom:18px}
.auth-alt{margin-top:16px;text-align:center}

.account{padding:34px 0}
.account-grid{display:grid;grid-template-columns:1fr 1.25fr;gap:24px;align-items:start;margin-top:18px}
.account-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}
.account-card h2{font-size:1.2rem;margin-top:0;margin-bottom:16px}
.account-card hr{border:0;border-top:1px solid var(--line);margin:20px 0}
.account-email{word-break:break-all}

.purchase-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:12px}
.purchase-item{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:14px 16px;border:1px solid var(--line);border-radius:12px;background:#fff}
.purchase-main{display:flex;flex-direction:column;gap:3px;min-width:0}
.purchase-title{font-weight:700;font-size:1rem;color:var(--ink);word-break:break-word}
.purchase-meta{font-size:.82rem}
.purchase-resend{margin:0;flex:0 0 auto}

.nav-user{display:flex;align-items:center;gap:12px;margin-left:10px}
.nav-user a{color:#cbd5e1;padding:8px 12px;border-radius:8px;font-size:.95rem;font-weight:500;white-space:nowrap}
.nav-user a:hover{color:#fff;background:rgba(255,255,255,.08);text-decoration:none}
.nav-user .nav-register{color:var(--ink);background:#fff}
.nav-user .nav-register:hover{background:#eef2ff;color:var(--indigo-d);text-decoration:none}
@media (max-width:860px){
  .account-grid{grid-template-columns:1fr}
  .nav-user{margin-left:auto}
}

/* ---------------- 响应式 ---------------- */
@media (max-width:860px){
  .hero{padding:44px 18px;margin:18px 0 4px}
  .hero h1{font-size:2rem}
  .product-detail{grid-template-columns:1fr;gap:22px}
  .nav{flex-wrap:wrap;gap:10px;justify-content:space-between}
  .nav-links{flex-wrap:wrap;gap:2px}
  .lang-switch{margin-left:auto}
  .lang-switch select{font-size:.8rem}
  .nav-dropdown-menu{position:static;min-width:0;box-shadow:none;border:0;padding:4px 0 0;display:flex;flex-wrap:wrap;gap:6px}
  .nav-dropdown:hover .nav-dropdown-menu,.nav-dropdown:focus-within .nav-dropdown-menu{display:flex}
}
@media (max-width:520px){
  .hero h1{font-size:1.7rem}
  .hero-stats{gap:14px 26px}
}

/* ===== FAQ 区块（GEO 答案优先内容） ===== */
.faq{margin:48px 0;padding:32px 0;border-top:1px solid rgba(255,255,255,.08)}
.faq .section-title{text-align:center;margin-bottom:24px}
.faq-list{display:grid;gap:12px;max-width:860px;margin:0 auto}
.faq-item{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.08);border-radius:12px;padding:4px 18px;transition:border-color .2s}
.faq-item[open]{border-color:rgba(99,102,241,.5)}
.faq-item summary{list-style:none;cursor:pointer;padding:14px 0;display:flex;align-items:center;justify-content:space-between}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary h3{margin:0;font-size:1.05rem;line-height:1.4;font-weight:600}
.faq-item summary::after{content:"+";font-size:1.4rem;color:var(--accent,#6366f1);font-weight:700;transition:transform .2s}
.faq-item[open] summary::after{content:"\2212";transform:rotate(180deg)}
.faq-item p{margin:0 0 16px;color:rgba(255,255,255,.78);line-height:1.7}