/* ========================================
   BitStars 比特星辰 · 星空风格官网样式
   ======================================== */

:root{
  --space-0:#02060f;
  --space-1:#050d22;
  --space-2:#0a1a3a;
  --space-3:#0e2a52;
  --gold:#d4af37;
  --gold-l:#f0cf6a;
  --cyan:#5fc8ff;
  --cyan-d:#2b7fd6;
  --text:#e6ecf5;
  --muted:#8ea3c0;
  --glass:rgba(14,38,78,0.42);
  --glass-bd:rgba(120,170,230,0.16);
  --shadow:0 24px 60px rgba(0,0,0,0.45);
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:"Microsoft YaHei","PingFang SC","Helvetica Neue",sans-serif;
  color:var(--text);
  background:var(--space-0);
  line-height:1.7;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
a{text-decoration:none;color:inherit}
ul{list-style:none}
.container{max-width:1180px;margin:0 auto;padding:0 24px}
.glass{
  background:var(--glass);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  border:1px solid var(--glass-bd);
  border-radius:16px;
}

/* ============ 星空背景 ============ */
.stars-bg{
  position:fixed;inset:0;z-index:-3;
  background:
    radial-gradient(1px 1px at 12% 18%,rgba(255,255,255,.9),transparent 60%),
    radial-gradient(1.2px 1.2px at 22% 62%,rgba(255,255,255,.7),transparent 60%),
    radial-gradient(1px 1px at 34% 38%,rgba(255,255,255,.85),transparent 60%),
    radial-gradient(1.5px 1.5px at 46% 74%,rgba(255,255,255,.95),transparent 60%),
    radial-gradient(1px 1px at 58% 26%,rgba(255,255,255,.7),transparent 60%),
    radial-gradient(1.3px 1.3px at 68% 58%,rgba(255,255,255,.8),transparent 60%),
    radial-gradient(1px 1px at 80% 16%,rgba(255,255,255,.6),transparent 60%),
    radial-gradient(1.6px 1.6px at 88% 70%,rgba(255,255,255,.9),transparent 60%),
    radial-gradient(1px 1px at 6% 88%,rgba(255,255,255,.5),transparent 60%),
    radial-gradient(1.2px 1.2px at 96% 44%,rgba(255,255,255,.75),transparent 60%),
    radial-gradient(1px 1px at 40% 10%,rgba(255,255,255,.6),transparent 60%),
    radial-gradient(1px 1px at 16% 48%,rgba(255,255,255,.7),transparent 60%),
    #02060f;
  background-size:260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,260px 260px,100% 100%;
  animation:twinkle 5s ease-in-out infinite alternate;
}
@keyframes twinkle{0%{opacity:.62}100%{opacity:1}}
.stars-bg::after{
  content:"";position:absolute;inset:0;
  background:radial-gradient(1px 1px at 28% 22%,rgba(95,200,255,.7),transparent 60%),
    radial-gradient(1px 1px at 72% 32%,rgba(212,175,55,.55),transparent 60%),
    radial-gradient(1px 1px at 52% 84%,rgba(95,200,255,.6),transparent 60%);
  background-size:340px 340px;
  animation:twinkle 7s ease-in-out infinite alternate-reverse;
}
.nebula{
  position:fixed;inset:-20%;z-index:-2;pointer-events:none;
  background:
    radial-gradient(ellipse 46% 40% at 22% 32%,rgba(43,127,214,.20),transparent 70%),
    radial-gradient(ellipse 40% 36% at 82% 24%,rgba(95,200,255,.14),transparent 70%),
    radial-gradient(ellipse 50% 44% at 66% 78%,rgba(120,60,200,.16),transparent 72%),
    radial-gradient(ellipse 36% 30% at 14% 82%,rgba(212,175,55,.10),transparent 70%);
  filter:blur(20px);
  animation:drift 24s ease-in-out infinite alternate;
}
@keyframes drift{0%{transform:translate3d(0,0,0)}100%{transform:translate3d(-3%,2%,0)}}
.shooting-star{
  position:fixed;top:8%;left:65%;width:2px;height:2px;z-index:-1;
  background:#fff;border-radius:50%;
  box-shadow:0 0 8px 2px rgba(95,200,255,.7),80px 30px 1px -1px rgba(255,255,255,.5);
  opacity:0;animation:meteor 6s ease-in infinite;
}
@keyframes meteor{
  0%{opacity:0;transform:translate3d(0,0,0) rotate(22deg)}
  4%{opacity:1}
  12%{opacity:0;transform:translate3d(-520px,215px,0) rotate(22deg)}
  100%{opacity:0;transform:translate3d(-520px,215px,0) rotate(22deg)}
}

/* ============ 导航 ============ */
.navbar{
  position:fixed;top:0;left:0;right:0;z-index:1000;
  background:rgba(2,6,15,.72);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid rgba(120,170,230,.10);
  transition:all .35s ease;
}
.navbar.scrolled{background:rgba(2,6,15,.92);box-shadow:0 6px 30px rgba(0,0,0,.5)}
.nav-content{display:flex;align-items:center;justify-content:space-between;height:68px}
.nav-brand{display:flex;align-items:center;gap:10px}
.nav-logo{height:34px;width:auto;filter:drop-shadow(0 0 6px rgba(95,200,255,.25))}
.brand-text{font-size:19px;font-weight:700;letter-spacing:2px;background:linear-gradient(135deg,#fff,var(--cyan));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.nav-links{display:flex;gap:34px}
.nav-links a{
  font-size:15px;color:rgba(230,236,245,.78);position:relative;padding:6px 0;
  transition:color .3s;
}
.nav-links a:hover,.nav-links a.active{color:#fff}
.nav-links a.active::after,.nav-links a:hover::after{
  content:"";position:absolute;left:0;right:0;bottom:-2px;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--gold));border-radius:2px;
}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer}
.nav-toggle span{width:24px;height:2px;background:#fff;border-radius:2px;transition:all .3s}

/* ============ 首屏 ============ */
.hero{
  min-height:100vh;display:flex;align-items:center;position:relative;
  padding:120px 0 80px;overflow:hidden;
}
.hero::before{
  content:"";position:absolute;inset:0;z-index:-1;
  background:radial-gradient(ellipse 70% 60% at 50% 45%,rgba(14,42,82,.55),transparent 70%);
}
.hero-content{text-align:center;max-width:820px;margin:0 auto}
.hero-badge{
  display:inline-block;font-size:12px;letter-spacing:4px;color:var(--cyan);
  border:1px solid rgba(95,200,255,.3);border-radius:30px;padding:7px 20px;margin-bottom:28px;
  background:rgba(95,200,255,.06);
}
.hero-title{font-size:52px;font-weight:800;line-height:1.25;letter-spacing:2px;margin-bottom:18px}
.title-line{display:block}
.title-line.accent{
  background:linear-gradient(135deg,var(--gold) 0%,var(--gold-l) 45%,var(--cyan) 100%);
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;
}
.hero-sub{font-size:20px;color:var(--gold);letter-spacing:3px;margin-bottom:22px;font-weight:500}
.hero-desc{font-size:16px;color:var(--muted);line-height:2;margin-bottom:38px}
.hero-cta{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:14px 34px;border-radius:8px;font-size:15px;font-weight:600;
  transition:all .35s ease;cursor:pointer;border:1px solid transparent;letter-spacing:.5px;
}
.btn-primary{
  background:linear-gradient(135deg,var(--gold),var(--gold-l));
  color:#241800;box-shadow:0 10px 30px rgba(212,175,55,.28);
}
.btn-primary:hover{transform:translateY(-3px);box-shadow:0 14px 40px rgba(212,175,55,.42)}
.btn-outline{
  background:transparent;color:#fff;border-color:rgba(95,200,255,.5);
}
.btn-outline:hover{border-color:var(--cyan);color:var(--cyan);box-shadow:0 0 24px rgba(95,200,255,.18)}
.hero-scroll{position:absolute;bottom:34px;left:50%;transform:translateX(-50%);text-align:center}
.hero-scroll span{font-size:11px;letter-spacing:3px;color:var(--muted);display:block;margin-bottom:8px}
.scroll-line{width:1px;height:40px;background:linear-gradient(to bottom,var(--cyan),transparent);margin:0 auto;animation:scrollHint 2s ease-in-out infinite}

/* ============ 通用区块 ============ */
.section{padding:96px 0;position:relative}
.section-alt{background:linear-gradient(180deg,transparent,rgba(10,26,58,.35),transparent)}
.section-head{text-align:center;margin-bottom:56px}
.section-eyebrow{font-size:12px;letter-spacing:4px;color:var(--cyan);margin-bottom:10px;font-weight:600}
.section-title{font-size:32px;font-weight:800;color:#fff;letter-spacing:1px}
.section-sub{font-size:15px;color:var(--muted);margin-top:12px}

/* ============ 数据指标 ============ */
.stats{position:relative;margin-top:-60px;z-index:5}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.stat-card{text-align:center;padding:34px 18px}
.stat-num{
  font-size:40px;font-weight:800;line-height:1;
  background:linear-gradient(135deg,var(--gold),var(--cyan));
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;
  margin-bottom:10px;
}
.stat-label{font-size:15px;color:#fff}
.stat-range{font-size:12px;color:var(--cyan);margin-top:6px;opacity:.85}

/* ============ 能力卡片 ============ */
.cap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.cap-card{padding:30px 26px;transition:all .4s ease}
.cap-card:hover{transform:translateY(-6px);border-color:rgba(95,200,255,.4);box-shadow:var(--shadow)}
.cap-icon{
  width:56px;height:56px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,rgba(95,200,255,.18),rgba(212,175,55,.12));
  border:1px solid var(--glass-bd);color:var(--cyan);margin-bottom:18px;
}
.cap-card h3{font-size:18px;color:#fff;margin-bottom:10px;font-weight:700}
.cap-card p{font-size:14px;color:var(--muted);line-height:1.75}

/* ============ 行业 ============ */
.ind-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.ind-card{padding:32px 28px;transition:all .4s ease}
.ind-card:hover{transform:translateY(-6px);box-shadow:var(--shadow)}
.ind-tag{
  display:inline-block;font-size:12px;letter-spacing:2px;color:var(--gold);
  border:1px solid rgba(212,175,55,.35);border-radius:20px;padding:5px 14px;margin-bottom:16px;
}
.ind-card h3{font-size:19px;color:#fff;margin-bottom:10px}
.ind-card>p{font-size:14px;color:var(--muted);line-height:1.75;margin-bottom:16px}
.ind-points{margin-top:6px}
.ind-points li{
  font-size:13.5px;color:rgba(230,236,245,.7);padding:6px 0 6px 20px;position:relative;
  border-top:1px solid rgba(120,170,230,.08);
}
.ind-points li::before{content:"";position:absolute;left:0;top:13px;width:7px;height:7px;border-radius:50%;background:var(--cyan);box-shadow:0 0 8px var(--cyan)}

/* ============ 使命 ============ */
.mission-box{padding:56px 40px;text-align:center;max-width:900px;margin:0 auto}
.mission-eyebrow{font-size:12px;letter-spacing:5px;color:var(--cyan);margin-bottom:18px}
.mission-text{font-size:34px;font-weight:800;line-height:1.5;color:#fff;margin-bottom:22px}
.mission-text .gold{color:var(--gold)}
.mission-box>p{font-size:15px;color:var(--muted);max-width:680px;margin:0 auto;line-height:2}

/* ============ 页脚 ============ */
.footer{background:rgba(2,6,15,.96);border-top:1px solid rgba(120,170,230,.1);padding-top:56px}
.footer-inner{display:grid;grid-template-columns:2.2fr 1fr 1fr 1fr;gap:40px;padding-bottom:44px}
.footer-logo{height:42px;margin-bottom:14px;filter:drop-shadow(0 0 10px rgba(95,200,255,.2))}
.footer-brand p{font-size:13.5px;color:var(--muted);line-height:1.9}
.footer-col h4{font-size:15px;color:#fff;margin-bottom:16px;font-weight:700}
.footer-col a{display:block;font-size:14px;color:var(--muted);margin-bottom:10px;transition:color .3s}
.footer-col a:hover{color:var(--cyan)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.06);padding:22px 0;text-align:center}
.footer-bottom span{font-size:13px;color:var(--muted)}
.footer-bottom .footer-sep{margin:0 8px;opacity:.55}
.footer-bottom a.footer-icp{font-size:13px;color:var(--muted);transition:color .3s}
.footer-bottom a.footer-icp:hover{color:var(--cyan)}

/* ============ 动画 ============ */
.reveal{opacity:0;transform:translateY(32px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:translateY(0)}

/* ============ 响应式 ============ */
@media(max-width:900px){
  .stats-grid{grid-template-columns:repeat(2,1fr)}
  .cap-grid,.ind-grid{grid-template-columns:1fr}
  .hero-title{font-size:34px}
  .nav-links{position:fixed;top:68px;left:0;right:0;flex-direction:column;gap:0;background:rgba(2,6,15,.98);padding:12px 24px 20px;border-bottom:1px solid rgba(120,170,230,.1);transform:translateY(-150%);transition:transform .4s}
  .nav-links.open{transform:translateY(0)}
  .nav-links a{padding:14px 0;border-bottom:1px solid rgba(255,255,255,.05)}
  .nav-toggle{display:flex}
  .footer-inner{grid-template-columns:1fr;gap:28px}
  .section{padding:64px 0}
  .stats{margin-top:0;padding-top:0}
}
@media(max-width:520px){
  .hero-title{font-size:28px}
  .hero-sub{font-size:16px}
  .section-title{font-size:24px}
  .mission-text{font-size:24px}
}