/* ===== 比特指纹浏览器 — 极客暗蓝·指纹科技风 ===== */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  /* 底色系统 */
  --bg: #080d1a;
  --bg2: #0e1525;
  --bg3: #131c2e;
  --bg4: #182338;
  /* 主色：电光蓝 */
  --p: #2563eb;
  --p2: #3b82f6;
  --p3: #60a5fa;
  /* 强调色：青 */
  --ac: #06b6d4;
  --ac2: #22d3ee;
  /* 成功/安全绿 */
  --gr: #10b981;
  --gr2: #34d399;
  /* 文字 */
  --t1: #f1f5f9;
  --t2: #94a3b8;
  --t3: #64748b;
  /* 玻璃 & 边框 */
  --glass: rgba(15,23,42,0.85);
  --glass-border: rgba(37,99,235,0.15);
  --border: rgba(37,99,235,0.12);
  --radius: 12px;
  --radius2: 16px;
  --radius3: 20px;
  --shadow: 0 8px 32px rgba(0,0,0,0.4);
  --shadow-blue: 0 4px 24px rgba(37,99,235,0.15);
  --trans: 0.3s cubic-bezier(0.4,0,0.2,1);
}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--t1);line-height:1.6;overflow-x:hidden}
body::before{content:"";position:fixed;inset:0;z-index:-1;background:radial-gradient(ellipse 80% 60% at 50% 0%,rgba(37,99,235,0.08) 0%,transparent 60%),radial-gradient(ellipse 60% 50% at 80% 80%,rgba(6,182,212,0.06) 0%,transparent 60%);pointer-events:none}

/* ---- 字体 ---- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&display=swap');

/* ---- 导航 ---- */
.nav-bar{position:sticky;top:0;z-index:100;background:rgba(8,13,26,0.85);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border-bottom:1px solid var(--glass-border);transition:var(--trans)}
.nav-bar.scrolled{background:rgba(8,13,26,0.95);box-shadow:0 4px 32px rgba(0,0,0,0.5)}
.nav-inner{max-width:1200px;margin:0 auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between;height:64px}
.nav-brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--t1);font-weight:700;font-size:1.2rem;letter-spacing:-0.02em}
.nav-brand img{height:32px;width:32px;border-radius:6px}
.nav-brand .accent{color:var(--p2);font-weight:800}
.nav-menu{display:flex;align-items:center;gap:32px}
.nav-menu a{text-decoration:none;color:var(--t2);font-size:0.9rem;font-weight:500;transition:var(--trans);position:relative}
.nav-menu a:hover{color:var(--p3)}
.nav-menu a::after{content:"";position:absolute;left:0;bottom:-4px;width:0;height:2px;background:linear-gradient(90deg,var(--p),var(--ac));border-radius:2px;transition:width var(--trans)}
.nav-menu a:hover::after{width:100%}
.nav-menu .btn-nav{background:linear-gradient(135deg,var(--p),var(--ac));color:#fff;padding:8px 20px;border-radius:8px;font-weight:600;font-size:0.85rem;transition:var(--trans);box-shadow:0 2px 12px rgba(37,99,235,0.3)}
.nav-menu .btn-nav:hover{transform:translateY(-1px);box-shadow:0 4px 20px rgba(37,99,235,0.45);color:#fff}
.nav-menu .btn-nav::after{display:none}
.nav-toggle{display:none;background:none;border:none;color:var(--t1);font-size:1.5rem;cursor:pointer;padding:4px}

/* ---- 通用节 ---- */
.sec{padding:100px 24px;max-width:1200px;margin:0 auto}
.sec-head{text-align:center;margin-bottom:56px}
.sec-head .label{display:inline-block;padding:6px 16px;border-radius:20px;font-size:0.8rem;font-weight:600;letter-spacing:0.05em;text-transform:uppercase;color:var(--ac2);background:rgba(6,182,212,0.1);border:1px solid rgba(6,182,212,0.2);margin-bottom:20px}
.sec-head h2{font-size:2.4rem;font-weight:800;letter-spacing:-0.03em;line-height:1.3;margin-bottom:12px}
.sec-head h2 em{background:linear-gradient(135deg,var(--p2),var(--ac2));-webkit-background-clip:text;-webkit-text-fill-color:transparent;font-style:normal}
.sec-head p{color:var(--t2);font-size:1rem;max-width:600px;margin:0 auto}

/* ---- Hero ---- */
.hero{padding:60px 24px 100px;max-width:1200px;margin:0 auto}
.hero-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center}
.hero-text .tag{display:inline-flex;align-items:center;gap:8px;padding:6px 14px;border-radius:20px;font-size:0.8rem;font-weight:600;color:var(--ac2);background:rgba(6,182,212,0.08);border:1px solid rgba(6,182,212,0.2);margin-bottom:24px}
.hero-text h1{font-size:3rem;font-weight:900;line-height:1.15;letter-spacing:-0.04em;margin-bottom:20px}
.hero-text h1 em{background:linear-gradient(135deg,var(--p2),var(--ac2),var(--p3));-webkit-background-clip:text;-webkit-text-fill-color:transparent;font-style:normal}
.hero-text .desc{font-size:1.05rem;color:var(--t2);line-height:1.7;margin-bottom:32px;max-width:480px}
.hero-btns{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.hero-btns .ver{font-size:0.78rem;color:var(--t3);margin-left:4px}
.btn-fill{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:10px;font-size:0.95rem;font-weight:600;text-decoration:none;transition:var(--trans);cursor:pointer;border:none;background:linear-gradient(135deg,var(--p),var(--ac));color:#fff;box-shadow:0 4px 20px rgba(37,99,235,0.35)}
.btn-fill:hover{transform:translateY(-2px);box-shadow:0 8px 32px rgba(37,99,235,0.5)}
.btn-line{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:10px;font-size:0.95rem;font-weight:600;text-decoration:none;transition:var(--trans);cursor:pointer;background:transparent;color:var(--t1);border:1.5px solid var(--border)}
.btn-line:hover{border-color:var(--p2);color:var(--p3);transform:translateY(-2px)}
.btn-muted{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:10px;font-size:0.95rem;font-weight:600;text-decoration:none;transition:var(--trans);cursor:pointer;background:var(--bg4);color:var(--t2);border:1px solid var(--border)}
.btn-muted:hover{background:var(--bg4);color:var(--t1);border-color:var(--p)}
.btn-white{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:10px;font-size:0.95rem;font-weight:600;text-decoration:none;transition:var(--trans);cursor:pointer;background:rgba(255,255,255,0.08);color:var(--t1);border:1px solid rgba(255,255,255,0.12)}
.btn-white:hover{background:rgba(255,255,255,0.14);border-color:rgba(255,255,255,0.25);transform:translateY(-2px)}

/* 可视化：指纹波纹 */
.vis-mock{position:relative;display:flex;align-items:center;justify-content:center}
.fp-ring{position:relative;width:320px;height:320px;border-radius:50%;display:flex;align-items:center;justify-content:center}
.fp-ring::before{content:"";position:absolute;inset:0;border-radius:50%;border:2px solid rgba(37,99,235,0.2);animation:fpExpand1 4s ease-out infinite}
.fp-ring::after{content:"";position:absolute;inset:30px;border-radius:50%;border:2px solid rgba(6,182,212,0.25);animation:fpExpand2 4s ease-out infinite .5s}
.fp-r2{position:absolute;inset:60px;border-radius:50%;border:2px solid rgba(37,99,235,0.15);animation:fpExpand3 4s ease-out infinite 1s}
.fp-r3{position:absolute;inset:90px;border-radius:50%;border:2px solid rgba(6,182,212,0.12);animation:fpExpand4 4s ease-out infinite 1.5s}
.fp-core{position:relative;z-index:2;width:100px;height:100px;border-radius:50%;background:linear-gradient(135deg,rgba(37,99,235,0.3),rgba(6,182,212,0.2));border:2px solid rgba(37,99,235,0.4);display:flex;align-items:center;justify-content:center;flex-direction:column;backdrop-filter:blur(8px);box-shadow:0 0 40px rgba(37,99,235,0.3)}
.fp-core .fp-icon{font-size:2rem;margin-bottom:2px}
.fp-core .fp-label{font-size:0.65rem;color:var(--p3);font-weight:700;letter-spacing:0.1em;text-transform:uppercase}
@keyframes fpExpand1{0%{transform:scale(1);opacity:1}100%{transform:scale(1.5);opacity:0}}
@keyframes fpExpand2{0%{transform:scale(1);opacity:1}100%{transform:scale(1.4);opacity:0}}
@keyframes fpExpand3{0%{transform:scale(1);opacity:1}100%{transform:scale(1.3);opacity:0}}
@keyframes fpExpand4{0%{transform:scale(1);opacity:1}100%{transform:scale(1.2);opacity:0}}
.vis-float{position:absolute;bottom:0;right:0;background:var(--glass);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border:1px solid rgba(37,99,235,0.2);border-radius:12px;padding:14px 18px;display:flex;align-items:center;gap:12px;font-size:0.8rem;color:var(--t1);box-shadow:var(--shadow-blue)}
.vis-float strong{color:var(--gr2);font-size:0.85rem;display:block;margin-bottom:2px}
.vis-float .vf-dot{width:8px;height:8px;border-radius:50%;background:var(--gr);animation:pulse-dot 2s ease-in-out infinite}
@keyframes pulse-dot{0%,100%{opacity:1;box-shadow:0 0 8px var(--gr)}50%{opacity:0.4;box-shadow:0 0 2px var(--gr)}}

/* 平台条 */
.plat-strip{background:var(--bg2);border-top:1px solid var(--border);border-bottom:1px solid var(--border);padding:0}
.plat-inner{max-width:1200px;margin:0 auto;padding:0 24px;display:flex;justify-content:center;gap:40px;flex-wrap:wrap;height:56px;align-items:center;overflow:hidden}
.pi{font-size:0.85rem;color:var(--t2);font-weight:500;display:flex;align-items:center;white-space:nowrap;transition:var(--trans)}
.pi:hover{color:var(--p3)}

/* 功能卡片 */
.feat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.feat-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius2);padding:32px 28px;transition:var(--trans);position:relative;overflow:hidden}
.feat-card:hover{transform:translateY(-3px);border-color:rgba(37,99,235,0.3);box-shadow:0 12px 40px rgba(37,99,235,0.08)}
.feat-card::before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,transparent,var(--p),var(--ac),transparent);opacity:0;transition:opacity var(--trans)}
.feat-card:hover::before{opacity:1}
.feat-card .fc-icon{font-size:2rem;display:block;margin-bottom:16px}
.feat-card h3{font-size:1.1rem;font-weight:700;margin-bottom:10px;color:var(--t1)}
.feat-card p{font-size:0.9rem;color:var(--t2);line-height:1.7}

/* Dark 区块 */
.dark-zone{background:linear-gradient(180deg,var(--bg2),var(--bg3),var(--bg2))}

/* 方案卡片 */
.extra-row{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.extra-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius2);padding:28px 24px;transition:var(--trans);position:relative}
.extra-card:hover{transform:translateY(-2px);border-color:rgba(37,99,235,0.25);box-shadow:var(--shadow-blue)}
.extra-card .ei{font-size:2rem;display:block;margin-bottom:14px}
.extra-card h3{font-size:1.05rem;font-weight:700;margin-bottom:8px}
.extra-card p{font-size:0.88rem;color:var(--t2);line-height:1.65}

/* 数据统计 */
.stat-row{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.stat-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius2);padding:32px 20px;text-align:center;transition:var(--trans)}
.stat-card:hover{border-color:rgba(37,99,235,0.25);box-shadow:var(--shadow-blue);transform:translateY(-2px)}
.stat-card .sn{font-size:2.4rem;font-weight:900;background:linear-gradient(135deg,var(--p2),var(--ac2));-webkit-background-clip:text;-webkit-text-fill-color:transparent;line-height:1.2;margin-bottom:8px;font-family:"Inter",sans-serif;letter-spacing:-0.03em}
.stat-card .sl{font-size:0.85rem;color:var(--t2);font-weight:500}

/* FAQ */
.faq-wrap{max-width:760px;margin:0 auto}
.faq-item{border:1px solid var(--border);border-radius:var(--radius);margin-bottom:10px;overflow:hidden;background:var(--bg2);transition:var(--trans)}
.faq-item.open{border-color:rgba(37,99,235,0.25);box-shadow:var(--shadow-blue)}
.faq-q{width:100%;background:none;border:none;padding:18px 24px;text-align:left;font-size:0.95rem;font-weight:600;color:var(--t1);cursor:pointer;display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq-q .arrow{font-size:0.7rem;color:var(--t3);transition:transform var(--trans)}
.faq-item.open .faq-q .arrow{transform:rotate(180deg);color:var(--p2)}
.faq-a{max-height:0;overflow:hidden;transition:max-height 0.4s ease,padding 0.4s ease;padding:0 24px;font-size:0.9rem;color:var(--t2);line-height:1.7}
.faq-item.open .faq-a{max-height:300px;padding:0 24px 20px}

/* CTA */
.cta-box{text-align:center;background:linear-gradient(135deg,rgba(37,99,235,0.08),rgba(6,182,212,0.06));border:1px solid rgba(37,99,235,0.2);border-radius:var(--radius3);padding:64px 32px}
.cta-box h2{font-size:2.2rem;font-weight:800;margin-bottom:12px;letter-spacing:-0.03em}
.cta-box p{color:var(--t2);font-size:1rem;margin-bottom:28px}
.cta-btns{display:flex;justify-content:center;gap:16px;flex-wrap:wrap}

/* Footer */
.footer{padding:60px 24px 30px;max-width:1200px;margin:0 auto;border-top:1px solid var(--border)}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:40px}
.footer-brand .fl{display:flex;align-items:center;gap:10px;font-size:1.1rem;font-weight:700;margin-bottom:12px}
.footer-brand .fl img{height:28px;width:28px;border-radius:5px}
.footer-brand .fl .fc{color:var(--p2)}
.footer-brand p{font-size:0.85rem;color:var(--t2);line-height:1.6;max-width:280px}
.footer-col h4{font-size:0.85rem;font-weight:700;color:var(--t1);margin-bottom:16px;text-transform:uppercase;letter-spacing:0.05em}
.footer-col a{display:block;font-size:0.85rem;color:var(--t2);text-decoration:none;margin-bottom:10px;transition:var(--trans)}
.footer-col a:hover{color:var(--p3)}
.footer-bottom{display:flex;justify-content:space-between;align-items:center;padding-top:24px;border-top:1px solid var(--border);font-size:0.8rem;color:var(--t3);flex-wrap:wrap;gap:12px}

/* ===== 下载页 ===== */
.dl-hero{padding:80px 24px 60px;text-align:center;max-width:1200px;margin:0 auto}
.dl-hero h1{font-size:2.8rem;font-weight:900;letter-spacing:-0.04em;margin-bottom:12px}
.dl-hero .dl-sub{color:var(--t2);font-size:1.05rem;margin-bottom:24px}
.dl-meta{display:flex;justify-content:center;gap:24px;flex-wrap:wrap}
.dl-meta span{font-size:0.85rem;color:var(--t2);display:flex;align-items:center;gap:6px}

.dl-cards{padding:0 24px 80px;max-width:1200px;margin:0 auto}
.dl-single-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}

.dl-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius2);padding:32px 24px;text-align:center;transition:var(--trans);position:relative}
.dl-card:hover{transform:translateY(-3px);border-color:rgba(37,99,235,0.3);box-shadow:var(--shadow-blue)}
.dl-card.primary{border-color:rgba(37,99,235,0.35);background:linear-gradient(180deg,rgba(37,99,235,0.06),var(--bg2))}
.dl-os{display:inline-block;padding:4px 14px;border-radius:20px;font-size:0.75rem;font-weight:700;color:var(--ac2);background:rgba(6,182,212,0.1);border:1px solid rgba(6,182,212,0.2);margin-bottom:16px}
.dl-card h3{font-size:1.3rem;font-weight:700;margin-bottom:8px}
.dl-card .dl-ver{font-size:0.8rem;color:var(--t3);margin-bottom:16px}
.dl-feats{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin-bottom:16px}
.dl-feats span{font-size:0.75rem;padding:4px 10px;border-radius:6px;background:rgba(37,99,235,0.08);color:var(--p3);border:1px solid rgba(37,99,235,0.12)}
.dl-card .dl-size{font-size:0.78rem;color:var(--t3);margin-bottom:20px}
.dl-card .btn-fill,.dl-card .btn-line{width:100%;justify-content:center}

.dl-extra-section{padding:0 24px 100px;max-width:1200px;margin:0 auto}
.section-header{text-align:center;margin-bottom:48px}
.section-header .label{display:inline-block;padding:6px 16px;border-radius:20px;font-size:0.8rem;font-weight:600;letter-spacing:0.05em;text-transform:uppercase;color:var(--ac2);background:rgba(6,182,212,0.1);border:1px solid rgba(6,182,212,0.2);margin-bottom:16px}
.section-header h2{font-size:2rem;font-weight:800;letter-spacing:-0.03em;margin-bottom:8px}
.section-header p{color:var(--t2);font-size:0.95rem;max-width:520px;margin:0 auto}
.dl-extra-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.dl-extra-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius2);padding:28px 24px;text-align:center;transition:var(--trans)}
.dl-extra-card:hover{transform:translateY(-2px);border-color:rgba(37,99,235,0.25);box-shadow:var(--shadow-blue)}
.dl-extra-card .ex-icon{font-size:2.4rem;margin-bottom:14px}
.dl-extra-card h4{font-size:1rem;font-weight:700;margin-bottom:10px}
.dl-extra-card p{font-size:0.85rem;color:var(--t2);line-height:1.65;margin-bottom:20px}

/* 安装步骤 */
.section.sm{padding:60px 24px 100px;max-width:1200px;margin:0 auto}
.dl-tips{max-width:760px;margin:0 auto}
.tp{display:flex;gap:20px;align-items:flex-start;margin-bottom:28px;padding:24px;background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);transition:var(--trans)}
.tp:hover{border-color:rgba(37,99,235,0.2)}
.tp-num{flex-shrink:0;width:40px;height:40px;border-radius:50%;background:linear-gradient(135deg,var(--p),var(--ac));color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:1rem}
.tp strong{display:block;font-size:1rem;color:var(--t1);margin-bottom:6px}
.tp p{font-size:0.88rem;color:var(--t2);line-height:1.7}

/* 规格卡片 */
.specs-card{max-width:760px;margin:0 auto;background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius2);overflow:hidden}
.spec-row{display:flex;padding:18px 24px;border-bottom:1px solid var(--border);align-items:flex-start;gap:16px}
.spec-row:last-child{border-bottom:none}
.spec-label{flex-shrink:0;width:120px;font-size:0.85rem;font-weight:600;color:var(--p3)}
.spec-value{font-size:0.88rem;color:var(--t2);line-height:1.6}

/* ===== 404 页 ===== */
.err-wrap{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:40px 24px}
.err-card{text-align:center;max-width:500px}
.err-num{font-size:8rem;font-weight:900;line-height:1;background:linear-gradient(135deg,var(--p2),var(--ac2),var(--p3));-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:16px;letter-spacing:-0.05em}
.err-card h1{font-size:1.6rem;font-weight:700;margin-bottom:12px}
.err-card p{color:var(--t2);font-size:0.95rem;line-height:1.65;margin-bottom:28px}
.err-btns{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}

/* ===== 响应式 ===== */
@media(max-width:1024px){
  .hero-grid{grid-template-columns:1fr;gap:40px;text-align:center}
  .hero-text .desc{margin-left:auto;margin-right:auto}
  .hero-btns{justify-content:center}
  .feat-grid{grid-template-columns:repeat(2,1fr)}
  .extra-row{grid-template-columns:repeat(2,1fr)}
  .stat-row{grid-template-columns:repeat(2,1fr)}
  .fp-ring{width:240px;height:240px}
  .fp-core{width:80px;height:80px}
  .fp-r2{inset:50px}.fp-r3{inset:75px}
  .dl-single-grid{grid-template-columns:1fr 1fr}
  .dl-card.primary{grid-column:span 2}
  .dl-extra-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:768px){
  .nav-menu{display:none;position:absolute;top:64px;left:0;right:0;background:rgba(8,13,26,0.98);backdrop-filter:blur(20px);flex-direction:column;padding:24px;gap:18px;border-bottom:1px solid var(--border)}
  .nav-menu.open{display:flex}
  .nav-toggle{display:block}
  .hero-text h1{font-size:2rem}
  .hero{padding:40px 24px 60px}
  .sec{padding:60px 16px}
  .sec-head h2{font-size:1.6rem}
  .feat-grid{grid-template-columns:1fr}
  .extra-row{grid-template-columns:1fr}
  .stat-row{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .fp-ring{width:200px;height:200px}
  .vis-float{position:relative;bottom:auto;right:auto;margin:24px auto 0;max-width:260px}
  .dl-hero h1{font-size:2rem}
  .dl-single-grid{grid-template-columns:1fr}
  .dl-card.primary{grid-column:span 1}
  .dl-extra-grid{grid-template-columns:1fr}
  .dl-meta{flex-direction:column;align-items:center;gap:8px}
  .cta-box{padding:40px 20px}
  .cta-box h2{font-size:1.6rem}
  .err-num{font-size:5rem}
  .plat-inner{gap:20px}
}