/* ============================================================
   贝影官网 · 全站共享样式 style.css
   用途：所有页面（首页、协议、隐私、更新日志）共用的设计系统。
   风格：深色科技风，蓝/青/白克制配色，高级有质感，面向企业客户。
   分区：变量 → 基础 → 导航 → 按钮 → Hero → 区块通用 → 各业务区块
        → 页脚 → 滚动揭示 → 文档页 → 响应式
   ============================================================ */

/* ---------- 设计变量 ---------- */
:root{
  --bg:#05070D;
  --bg-soft:#080D18;
  --panel:#0D1526;
  --panel-2:#101C33;
  --line:rgba(255,255,255,.08);
  --line-2:rgba(255,255,255,.14);
  --txt:#E8EEF8;
  --sub:#8C9BB8;
  --faint:#5C6882;
  --blue:#3B82F6;
  --blue-d:#1D4ED8;
  --blue-2:#2563EB;
  --cyan:#22D3EE;
  --light:#60A5FA;
  --grad:linear-gradient(135deg,#1D4ED8,#2563EB);
  --grad-text:linear-gradient(90deg,#60A5FA,#22D3EE);
  --radius:14px;
  --shadow:0 24px 60px rgba(0,0,0,.5);
  --nav-h:64px;
  --maxw:1180px;
  --ease:cubic-bezier(.22,1,.36,1);
}

/* ---------- 基础重置 ---------- */
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--txt);
  font-family:"MiSans",-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
ul{list-style:none}
img{max-width:100%;display:block}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}
::selection{background:rgba(37,99,235,.4);color:#fff}

/* ---------- 顶部导航 ---------- */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;height:var(--nav-h);
  display:flex;align-items:center;transition:background .3s,border-color .3s;
  border-bottom:1px solid transparent}
.nav.scrolled{background:rgba(7,11,20,.82);backdrop-filter:blur(16px);
  -webkit-backdrop-filter:blur(16px);border-bottom:1px solid var(--line)}
.nav-inner{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px;
  display:flex;align-items:center;justify-content:space-between}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:19px;
  letter-spacing:1.5px;color:var(--txt)}
.brand-mark{width:30px;height:30px;flex:none}
.nav-links{display:flex;align-items:center;gap:4px}
.nav-links a{color:var(--sub);font-size:14.5px;padding:8px 14px;border-radius:8px;
  transition:color .2s,background .2s}
.nav-links a:hover{color:var(--txt);background:rgba(255,255,255,.06)}
.nav-links .nav-cta{margin-left:8px;color:#fff;background:var(--grad);padding:9px 18px;font-weight:600}
.nav-links .nav-cta:hover{background:linear-gradient(135deg,#2563EB,#3B82F6)}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;width:40px;height:40px;
  flex-direction:column;align-items:center;justify-content:center;gap:5px}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--txt);border-radius:2px;transition:.3s}

/* ---------- 按钮 ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:13px 28px;border-radius:11px;font-size:15px;font-weight:600;
  font-family:inherit;cursor:pointer;border:none;transition:transform .2s,box-shadow .2s,background .2s,border-color .2s}
.btn:active{transform:translateY(1px)}
.btn:disabled,.btn.disabled{opacity:.55;cursor:not-allowed;pointer-events:none}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 10px 28px rgba(37,99,235,.35)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 34px rgba(37,99,235,.5)}
.btn-ghost{background:rgba(255,255,255,.05);color:var(--txt);border:1px solid var(--line-2)}
.btn-ghost:hover{background:rgba(255,255,255,.1);border-color:rgba(255,255,255,.25)}
.btn-lg{padding:15px 34px;font-size:16px}

/* ---------- 首屏 Hero ---------- */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;overflow:hidden;
  background:radial-gradient(1200px 600px at 72% -10%,rgba(37,99,235,.16),transparent 60%),var(--bg)}
.hero canvas{position:absolute;inset:0;width:100%;height:100%}
.hero-inner{position:relative;z-index:2;width:100%}
.hero-copy{max-width:600px}
.badge{display:inline-flex;align-items:center;gap:8px;font-size:13px;color:var(--cyan);
  border:1px solid rgba(34,211,238,.3);background:rgba(34,211,238,.07);
  padding:6px 14px;border-radius:999px;width:max-content;margin-bottom:24px;letter-spacing:.5px}
.badge .dot{width:6px;height:6px;border-radius:50%;background:var(--cyan);box-shadow:0 0 8px var(--cyan)}
.hero h1{font-size:52px;font-weight:800;line-height:1.16;letter-spacing:1px}
.hero h1 .hl{background:var(--grad-text);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero .hero-sub{color:var(--sub);font-size:17px;margin-top:20px;max-width:520px;line-height:1.8}
.hero .cta{display:flex;gap:14px;margin-top:36px;flex-wrap:wrap}
.hero-meta{position:absolute;bottom:36px;left:0;right:0;z-index:2;
  display:flex;justify-content:space-between;align-items:flex-end;color:var(--faint);font-size:13px}
.hero-meta .scroll-hint{display:flex;align-items:center;gap:8px;letter-spacing:1px}
.hero-meta .mouse-ico{width:20px;height:30px;border:1.5px solid var(--line-2);border-radius:11px;position:relative}
.hero-meta .mouse-ico::after{content:"";position:absolute;top:5px;left:50%;transform:translateX(-50%);
  width:3px;height:6px;border-radius:2px;background:var(--sub);animation:wheel 1.6s infinite}
@keyframes wheel{0%{opacity:1;top:5px}70%{opacity:0;top:13px}100%{opacity:0}}

/* ---------- 区块通用 ---------- */
.section{padding:104px 0;position:relative;scroll-margin-top:var(--nav-h)}
.section-head{text-align:center;max-width:680px;margin:0 auto 60px}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:600;
  letter-spacing:2px;color:var(--light);text-transform:uppercase;margin-bottom:16px}
.eyebrow::before,.eyebrow::after{content:"";width:22px;height:1px;background:linear-gradient(90deg,transparent,var(--light))}
.eyebrow::after{background:linear-gradient(90deg,var(--light),transparent)}
.sec-title{font-size:36px;font-weight:800;letter-spacing:.5px;line-height:1.3}
.sec-desc{color:var(--sub);margin-top:16px;font-size:16px;line-height:1.8}

/* ---------- 核心功能 ---------- */
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.feature-card{background:linear-gradient(160deg,var(--panel),#0A1220);
  border:1px solid var(--line);border-radius:var(--radius);padding:30px 26px;
  transition:transform .3s var(--ease),border-color .3s,box-shadow .3s;position:relative;overflow:hidden}
.feature-card::before{content:"";position:absolute;inset:0;
  background:radial-gradient(320px 180px at 20% 0%,rgba(59,130,246,.12),transparent 70%);
  opacity:0;transition:opacity .3s}
.feature-card:hover{transform:translateY(-5px);border-color:rgba(59,130,246,.42);box-shadow:var(--shadow)}
.feature-card:hover::before{opacity:1}
.feature-icon{width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;
  background:rgba(59,130,246,.12);border:1px solid rgba(59,130,246,.25);margin-bottom:20px;color:var(--light)}
.feature-icon svg{width:24px;height:24px}
.feature-card h3{font-size:18px;font-weight:700;margin-bottom:10px;letter-spacing:.5px}
.feature-card p{color:var(--sub);font-size:14.5px;line-height:1.75}

/* ---------- 工作流程 ---------- */
.flow{display:grid;grid-template-columns:repeat(5,1fr);gap:16px;position:relative}
.flow-step{position:relative;padding:26px 20px;text-align:center;
  background:linear-gradient(160deg,var(--panel),#0A1220);border:1px solid var(--line);
  border-radius:var(--radius)}
.flow-step .num{width:42px;height:42px;margin:0 auto 16px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;font-weight:800;font-size:17px;
  background:var(--grad);color:#fff;box-shadow:0 8px 20px rgba(37,99,235,.35);font-variant-numeric:tabular-nums}
.flow-step h4{font-size:16px;font-weight:700;margin-bottom:8px}
.flow-step p{color:var(--sub);font-size:13px;line-height:1.65}
.flow-step .arrow{position:absolute;top:46px;right:-15px;z-index:2;color:var(--blue);font-size:18px}
@media(max-width:900px){.flow-step .arrow{display:none}}

/* ---------- 优势 ---------- */
.adv-wrap{display:grid;grid-template-columns:1.05fr 1fr;gap:56px;align-items:center}
.adv-visual{position:relative;border-radius:18px;overflow:hidden;border:1px solid var(--line);
  background:linear-gradient(160deg,#0E1830,#0A1220);padding:34px;min-height:380px;
  box-shadow:var(--shadow)}
.adv-list{display:flex;flex-direction:column;gap:14px}
.adv-item{display:flex;gap:16px;padding:20px;border-radius:var(--radius);
  background:rgba(255,255,255,.03);border:1px solid var(--line);transition:.3s}
.adv-item:hover{border-color:rgba(34,211,238,.3);background:rgba(34,211,238,.05)}
.adv-item .ic{width:42px;height:42px;flex:none;border-radius:10px;display:flex;align-items:center;justify-content:center;
  background:rgba(34,211,238,.1);border:1px solid rgba(34,211,238,.22);color:var(--cyan)}
.adv-item .ic svg{width:21px;height:21px}
.adv-item h4{font-size:16px;font-weight:700;margin-bottom:4px}
.adv-item p{color:var(--sub);font-size:14px;line-height:1.7}

/* ---------- 更新日志 ---------- */
.log-list{max-width:820px;margin:0 auto;display:flex;flex-direction:column;gap:18px}
.log-item{background:linear-gradient(160deg,var(--panel),#0A1220);border:1px solid var(--line);
  border-radius:var(--radius);padding:26px 28px}
.log-item .log-head{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin-bottom:16px}
.log-item .ver{font-size:19px;font-weight:800;color:var(--light);letter-spacing:.5px;font-variant-numeric:tabular-nums}
.log-item .tag{font-size:12px;padding:3px 10px;border-radius:999px;background:rgba(59,130,246,.15);
  color:var(--light);border:1px solid rgba(59,130,246,.3)}
.log-item .date{margin-left:auto;color:var(--faint);font-size:13px;font-variant-numeric:tabular-nums}
.log-item ul{display:flex;flex-direction:column;gap:8px}
.log-item li{position:relative;padding-left:18px;color:var(--sub);font-size:14.5px;line-height:1.7}
.log-item li::before{content:"";position:absolute;left:0;top:10px;width:6px;height:6px;border-radius:50%;
  background:var(--cyan);box-shadow:0 0 6px rgba(34,211,238,.6)}
.log-more{text-align:center;margin-top:36px}
.link-btn{color:var(--light);font-size:14.5px;font-weight:600;display:inline-flex;align-items:center;gap:6px;transition:gap .2s}
.link-btn:hover{gap:10px}

/* ---------- FAQ ---------- */
.faq{max-width:820px;margin:0 auto}
.faq-item{border:1px solid var(--line);border-radius:12px;margin-bottom:14px;
  background:linear-gradient(160deg,var(--panel),#0A1220);overflow:hidden}
.faq-item summary{list-style:none;cursor:pointer;padding:20px 24px;display:flex;
  justify-content:space-between;align-items:center;gap:16px;font-size:15.5px;font-weight:600}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary .pm{flex:none;width:22px;height:22px;position:relative;transition:transform .3s}
.faq-item summary .pm::before,.faq-item summary .pm::after{content:"";position:absolute;
  background:var(--light);border-radius:2px}
.faq-item summary .pm::before{top:50%;left:0;right:0;height:2px;transform:translateY(-50%)}
.faq-item summary .pm::after{left:50%;top:0;bottom:0;width:2px;transform:translateX(-50%);transition:.3s}
.faq-item[open] summary .pm::after{transform:translateX(-50%) scaleY(0)}
.faq-body{padding:0 24px 22px;color:var(--sub);font-size:14.5px;line-height:1.85}

/* ---------- 下载 ---------- */
.download-box{max-width:860px;margin:0 auto;text-align:center;border-radius:22px;
  border:1px solid var(--line-2);position:relative;overflow:hidden;padding:64px 40px;
  background:
    radial-gradient(600px 260px at 50% 0%,rgba(37,99,235,.2),transparent 70%),
    linear-gradient(160deg,#0E1830,#0A1220)}
.download-box .os{display:inline-flex;align-items:center;gap:8px;color:var(--sub);font-size:13px;
  letter-spacing:1px;margin-top:18px}
.download-box h2{font-size:30px;font-weight:800;margin:18px 0 12px}
.download-box p{color:var(--sub);max-width:520px;margin:0 auto}
.download-cta{margin-top:34px}
.download-note{margin-top:22px;color:var(--faint);font-size:13px}
.beta-pill{display:inline-flex;align-items:center;gap:8px;margin-top:26px;padding:10px 22px;border-radius:999px;
  background:rgba(255,255,255,.05);border:1px dashed var(--line-2);color:var(--sub);font-size:14px}
.beta-pill .dot{width:8px;height:8px;border-radius:50%;background:#F59E0B;box-shadow:0 0 8px #F59E0B;animation:pulse 1.8s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.4}}

/* ---------- 联系我们 ---------- */
.contact-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:22px;max-width:860px;margin:0 auto}
.contact-card{text-align:center;padding:38px 28px;border-radius:var(--radius);
  background:linear-gradient(160deg,var(--panel),#0A1220);border:1px solid var(--line)}
.contact-card .ic{width:54px;height:54px;margin:0 auto 18px;border-radius:14px;display:flex;
  align-items:center;justify-content:center;background:rgba(59,130,246,.12);
  border:1px solid rgba(59,130,246,.25);color:var(--light)}
.contact-card .ic svg{width:26px;height:26px}
.contact-card h4{font-size:17px;font-weight:700;margin-bottom:8px}
.contact-card .val{font-size:20px;font-weight:700;letter-spacing:1px;color:var(--txt);font-variant-numeric:tabular-nums}
.contact-card p{color:var(--sub);font-size:13.5px;margin-top:8px}

/* ---------- 页脚 ---------- */
.footer{border-top:1px solid var(--line);background:var(--bg-soft);padding:64px 0 30px;margin-top:20px}
.footer-top{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:40px}
.footer-brand .brand{margin-bottom:16px}
.footer-brand p{color:var(--sub);font-size:13.5px;line-height:1.8;max-width:300px}
.footer-col h5{font-size:14px;font-weight:700;margin-bottom:18px;color:var(--txt)}
.footer-col a{display:block;color:var(--sub);font-size:13.5px;padding:6px 0;transition:color .2s}
.footer-col a:hover{color:var(--light)}
.footer-bottom{margin-top:48px;padding-top:24px;border-top:1px solid var(--line);
  display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;
  color:var(--faint);font-size:13px}
.footer-bottom a{color:var(--faint)}
.footer-bottom a:hover{color:var(--sub)}
.beian{display:flex;gap:18px;flex-wrap:wrap}

/* ---------- 滚动揭示 ---------- */
.reveal{opacity:0;transform:translateY(26px);
  transition:opacity .75s var(--ease),transform .75s var(--ease)}
.reveal.in{opacity:1;transform:none}
.reveal[data-d="1"]{transition-delay:.08s}
.reveal[data-d="2"]{transition-delay:.16s}
.reveal[data-d="3"]{transition-delay:.24s}
.reveal[data-d="4"]{transition-delay:.32s}
@media(prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}

/* ---------- 文档页（协议/隐私/更新日志） ---------- */
.doc{padding:calc(var(--nav-h) + 56px) 0 80px}
.doc-inner{max-width:860px;margin:0 auto}
.doc-header{margin-bottom:40px;padding-bottom:28px;border-bottom:1px solid var(--line)}
.doc-header h1{font-size:32px;font-weight:800;margin-bottom:12px}
.doc-header .meta{color:var(--faint);font-size:14px}
.doc h2{font-size:20px;font-weight:700;margin:38px 0 16px;letter-spacing:.5px}
.doc h3{font-size:16.5px;font-weight:700;margin:26px 0 12px;color:var(--light)}
.doc p,.doc li{color:var(--sub);font-size:15px;line-height:1.9}
.doc ul{margin:10px 0;display:flex;flex-direction:column;gap:8px}
.doc ul li{padding-left:18px;position:relative}
.doc ul li::before{content:"";position:absolute;left:2px;top:12px;width:5px;height:5px;border-radius:50%;background:var(--blue)}
.doc .note{margin:18px 0;padding:16px 20px;border-radius:10px;background:rgba(59,130,246,.08);
  border-left:3px solid var(--blue);color:var(--sub);font-size:14px}
.doc table{width:100%;border-collapse:collapse;margin:16px 0;font-size:14px;
  border:1px solid var(--line);border-radius:10px;overflow:hidden}
.doc th,.doc td{padding:12px 16px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
.doc th{background:rgba(59,130,246,.1);color:var(--txt);font-weight:600;white-space:nowrap}
.doc td{color:var(--sub)}
.doc tr:last-child td{border-bottom:none}
.toc{margin:24px 0;padding:20px 24px;border-radius:12px;background:var(--panel);border:1px solid var(--line)}
.toc a{display:block;color:var(--sub);font-size:14px;padding:5px 0}
.toc a:hover{color:var(--light)}
.back-link{display:inline-flex;align-items:center;gap:7px;color:var(--sub);font-size:14px;margin-bottom:28px}
.back-link:hover{color:var(--light)}

/* ---------- 响应式 ---------- */
@media(max-width:960px){
  .feature-grid{grid-template-columns:repeat(2,1fr)}
  .flow{grid-template-columns:repeat(2,1fr)}
  .adv-wrap{grid-template-columns:1fr;gap:32px}
  .footer-top{grid-template-columns:1fr 1fr;gap:32px}
}
@media(max-width:720px){
  .nav-links{position:fixed;top:var(--nav-h);left:0;right:0;flex-direction:column;align-items:stretch;
    gap:2px;padding:14px 20px 22px;background:rgba(7,11,20,.97);backdrop-filter:blur(16px);
    border-bottom:1px solid var(--line);transform:translateY(-130%);transition:transform .3s var(--ease)}
  .nav-links.open{transform:translateY(0)}
  .nav-links a{padding:13px 14px;font-size:15px}
  .nav-links .nav-cta{margin:8px 0 0;text-align:center}
  .nav-toggle{display:flex}
  .hero h1{font-size:38px}
  .hero .hero-sub{font-size:15.5px}
  .hero-meta{display:none}
  .section{padding:72px 0}
  .sec-title{font-size:27px}
  .feature-grid{grid-template-columns:1fr}
  .flow{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .download-box{padding:48px 24px}
  .footer-top{grid-template-columns:1fr;gap:28px}
}