/* ============================================================
   金缔数据分析平台 · 官网落地页
   深色科技风 + 抖音品牌色（#25F4EE / #FE2C55）
   ============================================================ */

:root{
  --bg:#0B0D14;
  --bg-alt:#0F121C;
  --surface:rgba(255,255,255,.04);
  --surface-2:rgba(255,255,255,.06);
  --line:rgba(255,255,255,.10);
  --line-strong:rgba(255,255,255,.18);
  --text:#EDEFF5;
  --text-dim:#9BA3B4;
  --text-mute:#6F7787;
  --cyan:#25F4EE;
  --pink:#FE2C55;
  --grad:linear-gradient(100deg,var(--cyan),#8AB4FF 45%,var(--pink));
  --radius:16px;
  --radius-lg:22px;
  --shadow:0 24px 60px -20px rgba(0,0,0,.75);
  --wrap:1160px;
}

*,*::before,*::after{box-sizing:border-box}

html{scroll-behavior:smooth}

body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC",
              system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",sans-serif;
  font-size:16px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}

img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none}
h1,h2,h3{line-height:1.25;margin:0;letter-spacing:-.01em}
p{margin:0}

.wrap{width:100%;max-width:var(--wrap);margin:0 auto;padding:0 24px}
.wrap-narrow{max-width:820px}

.grad{
  background:var(--grad);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}

/* ---------------- 按钮 ---------------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  border:1px solid transparent;border-radius:999px;
  font-weight:600;white-space:nowrap;
  transition:transform .18s ease,box-shadow .18s ease,background .18s ease,border-color .18s ease;
}
.btn-sm{padding:9px 20px;font-size:14px}
.btn-lg{padding:15px 34px;font-size:16px}

.btn-primary{
  background:linear-gradient(100deg,var(--pink),#FF5C7A 60%,#FF8A5C);
  color:#fff;
  box-shadow:0 10px 30px -10px rgba(254,44,85,.75);
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 38px -12px rgba(254,44,85,.9)}

.btn-ghost{
  background:var(--surface);color:var(--text);border-color:var(--line-strong);
}
.btn-ghost:hover{background:var(--surface-2);transform:translateY(-2px)}

/* ---------------- 顶部导航 ---------------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(11,13,20,.72);
  backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid transparent;
  transition:border-color .25s ease,background .25s ease;
}
.site-header.is-stuck{border-bottom-color:var(--line);background:rgba(11,13,20,.9)}

.header-inner{display:flex;align-items:center;gap:24px;height:68px}

.brand{display:flex;align-items:center;gap:11px;flex-shrink:0}
.brand-mark{width:32px;height:32px;flex-shrink:0}
.brand-text{font-size:16px;font-weight:700;letter-spacing:.02em;display:flex;flex-direction:column;line-height:1.15}
.brand-text em{font-style:normal;font-size:11px;font-weight:500;color:var(--text-mute);letter-spacing:.14em}

.nav{display:flex;gap:26px;margin-left:auto;font-size:14.5px;color:var(--text-dim)}
.nav a{transition:color .16s ease}
.nav a:hover{color:var(--text)}

.header-cta{display:flex;align-items:center;gap:10px;margin-left:auto}
.nav ~ .header-cta{margin-left:0}

.nav-toggle{
  display:none;flex-direction:column;justify-content:center;gap:4px;
  width:40px;height:38px;padding:0 9px;
  background:var(--surface);border:1px solid var(--line);border-radius:10px;cursor:pointer;
}
.nav-toggle span{display:block;height:2px;background:var(--text);border-radius:2px;transition:transform .2s ease,opacity .2s ease}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(6px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-6px) rotate(-45deg)}

/* ---------------- Hero ---------------- */
.hero{position:relative;padding:78px 0 90px;overflow:hidden}
.hero-glow{
  position:absolute;inset:-30% -10% auto -10%;height:720px;z-index:0;
  background:
    radial-gradient(60% 55% at 22% 32%,rgba(37,244,238,.20),transparent 70%),
    radial-gradient(55% 50% at 78% 24%,rgba(254,44,85,.22),transparent 70%);
  filter:blur(10px);pointer-events:none;
}
.hero-inner{position:relative;z-index:1;max-width:840px;margin:0 auto;text-align:center}

.eyebrow{
  display:inline-block;margin-bottom:18px;
  padding:6px 15px;border-radius:999px;
  background:var(--surface);border:1px solid var(--line);
  font-size:12.5px;font-weight:600;letter-spacing:.14em;color:var(--text-dim);
}

.hero h1{font-size:clamp(30px,5.2vw,54px);font-weight:800;letter-spacing:-.02em}
.lead{margin-top:22px;font-size:clamp(15px,1.6vw,17.5px);color:var(--text-dim);line-height:1.85}
.lead strong{color:var(--text);font-weight:600}

.hero-actions{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-top:34px}

.hero-stats{
  display:grid;grid-template-columns:repeat(4,1fr);gap:14px;
  margin:46px 0 0;padding:0;list-style:none;
}
.hero-stats li{
  padding:18px 12px;border-radius:var(--radius);
  background:var(--surface);border:1px solid var(--line);
}
.hero-stats b{display:block;font-size:20px;font-weight:700;background:var(--grad);
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;color:transparent}
.hero-stats span{display:block;margin-top:3px;font-size:12.5px;color:var(--text-mute)}

/* ---------------- 截图外框 ---------------- */
.shot{
  position:relative;margin:0;border-radius:var(--radius-lg);overflow:hidden;
  background:linear-gradient(180deg,rgba(255,255,255,.09),rgba(255,255,255,.02));
  border:1px solid var(--line-strong);
  box-shadow:var(--shadow);
}
.shot-hero{position:relative;z-index:1;margin-top:64px}
.shot-bar{
  display:flex;align-items:center;gap:7px;
  padding:11px 16px;border-bottom:1px solid var(--line);
  background:rgba(255,255,255,.03);
}
.shot-bar i{width:10px;height:10px;border-radius:50%;background:rgba(255,255,255,.18)}
.shot-bar i:first-child{background:rgba(254,44,85,.6)}
.shot-bar i:nth-child(2){background:rgba(255,190,80,.55)}
.shot-bar i:nth-child(3){background:rgba(37,244,238,.55)}
.shot-bar span{margin-left:10px;font-size:11.5px;color:var(--text-mute);letter-spacing:.04em}
.shot img{width:100%}

.shot-tab{max-width:1000px;margin:0 auto}
.shot-caption{margin-top:18px;text-align:center;color:var(--text-mute);font-size:13.5px}

/* ---------------- 通用区块 ---------------- */
.section{padding:96px 0}
.section-alt{background:var(--bg-alt);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}

.sec-head{max-width:720px;margin:0 auto 52px;text-align:center}
.sec-head h2{font-size:clamp(24px,3.4vw,36px);font-weight:800}
.sec-sub{margin-top:16px;color:var(--text-dim);font-size:15.5px}

.grid{display:grid;gap:20px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}

.card{
  padding:28px 24px;border-radius:var(--radius);
  background:var(--surface);border:1px solid var(--line);
  transition:transform .2s ease,border-color .2s ease,background .2s ease;
}
.card:hover{transform:translateY(-4px);border-color:var(--line-strong);background:var(--surface-2)}
.card h3{font-size:17px;font-weight:700;margin-bottom:10px}
.card p{color:var(--text-dim);font-size:14.5px;line-height:1.8}
.card p b{color:var(--text);font-weight:600}

.card-ico{
  width:44px;height:44px;margin-bottom:16px;
  display:flex;align-items:center;justify-content:center;
  font-size:21px;border-radius:13px;
  background:linear-gradient(140deg,rgba(37,244,238,.16),rgba(254,44,85,.16));
  border:1px solid var(--line-strong);
}
.card-hl{
  background:linear-gradient(150deg,rgba(37,244,238,.10),rgba(254,44,85,.10));
  border-color:rgba(254,44,85,.32);
}

/* ---------------- 截图 Tabs ---------------- */
.tabs{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-bottom:32px}
.tab{
  padding:10px 20px;border-radius:999px;cursor:pointer;
  background:var(--surface);border:1px solid var(--line);
  color:var(--text-dim);font-size:14px;font-weight:600;font-family:inherit;
  transition:all .18s ease;
}
.tab:hover{color:var(--text);border-color:var(--line-strong)}
.tab.is-active{
  color:#fff;border-color:transparent;
  background:linear-gradient(100deg,var(--pink),#FF6B7F);
  box-shadow:0 8px 24px -10px rgba(254,44,85,.8);
}

/* ---------------- 流程 ---------------- */
.steps{
  display:grid;grid-template-columns:repeat(3,1fr);gap:20px;
  list-style:none;margin:0;padding:0;counter-reset:step;
}
.steps li{
  position:relative;padding:30px 26px;border-radius:var(--radius);
  background:var(--surface);border:1px solid var(--line);
}
.step-no{
  display:block;margin-bottom:14px;
  font-size:13px;font-weight:800;letter-spacing:.16em;
  background:var(--grad);-webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}
.steps h3{font-size:17px;margin-bottom:10px}
.steps p{color:var(--text-dim);font-size:14.5px;line-height:1.8}

/* ---------------- FAQ ---------------- */
.faq{display:flex;flex-direction:column;gap:12px}
.faq details{
  border-radius:var(--radius);background:var(--surface);border:1px solid var(--line);
  overflow:hidden;transition:border-color .2s ease;
}
.faq details[open]{border-color:var(--line-strong);background:var(--surface-2)}
.faq summary{
  padding:18px 22px;cursor:pointer;font-weight:600;font-size:15.5px;
  list-style:none;display:flex;justify-content:space-between;align-items:center;gap:16px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:"+";flex-shrink:0;font-size:19px;font-weight:400;color:var(--text-mute);
  transition:transform .2s ease,color .2s ease;
}
.faq details[open] summary::after{content:"−";color:var(--pink)}
.faq p{padding:0 22px 20px;color:var(--text-dim);font-size:14.5px;line-height:1.85}

/* ---------------- CTA ---------------- */
.cta-band{
  position:relative;padding:92px 0;
  background:
    radial-gradient(70% 130% at 50% 0%,rgba(254,44,85,.20),transparent 70%),
    radial-gradient(60% 120% at 12% 100%,rgba(37,244,238,.16),transparent 70%),
    var(--bg-alt);
  border-top:1px solid var(--line);
}
.cta-inner{text-align:center;max-width:720px}
.cta-inner h2{font-size:clamp(24px,3.4vw,36px);font-weight:800}
.cta-inner p{margin:16px 0 32px;color:var(--text-dim)}

/* ---------------- 页脚 ---------------- */
.site-footer{background:var(--bg);border-top:1px solid var(--line);padding:52px 0 30px}
.footer-inner{display:flex;justify-content:space-between;gap:40px;flex-wrap:wrap}
.footer-brand{display:flex;gap:12px;align-items:flex-start}
.footer-brand strong{font-size:15px}
.footer-brand p{margin-top:5px;color:var(--text-mute);font-size:13px}
.footer-nav{display:flex;gap:22px;flex-wrap:wrap;font-size:14px;color:var(--text-dim);align-self:center}
.footer-nav a:hover{color:var(--text)}
.footer-bottom{
  margin-top:36px;padding-top:22px;border-top:1px solid var(--line);
  color:var(--text-mute);font-size:13px;
}
.footer-bottom a{color:var(--text-dim)}

/* ---------------- 入场动画 ---------------- */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .6s ease,transform .6s ease}
.reveal.is-in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
  *{transition-duration:.01ms !important}
}

/* ---------------- 响应式 ---------------- */
@media (max-width:1000px){
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .steps{grid-template-columns:1fr}
}

@media (max-width:820px){
  .nav{
    position:absolute;top:68px;left:0;right:0;
    flex-direction:column;gap:0;margin:0;padding:8px 24px 18px;
    background:rgba(11,13,20,.98);border-bottom:1px solid var(--line);
    display:none;
  }
  .nav.is-open{display:flex}
  .nav a{padding:13px 0;border-bottom:1px solid var(--line);font-size:15px}
  .nav a:last-child{border-bottom:none}
  .nav-toggle{display:flex}
  .header-cta .btn{display:none}
  .header-cta{margin-left:auto}
  .hero{padding:52px 0 68px}
  .section{padding:68px 0}
  .hero-stats{grid-template-columns:repeat(2,1fr);margin-top:34px}
  .shot-hero{margin-top:44px}
  .cta-band{padding:68px 0}
}

@media (max-width:560px){
  .wrap{padding:0 18px}
  .grid-3,.grid-4{grid-template-columns:1fr}
  .hero-actions .btn{width:100%}
  .card{padding:24px 20px}
  .tabs{gap:8px}
  .tab{padding:9px 16px;font-size:13px}
  .footer-inner{flex-direction:column;gap:26px}
}