/* ---------- Reset & Base ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;
  color:#e0e6ed;background:#070e1a;line-height:1.7;overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
ul{list-style:none}
img{display:block;max-width:100%;height:auto}

/* ---------- Palette ---------- */
:root{
  --primary:#3bacff;
  --primary-dark:#1a7ad4;
  --gold:#f5a623;
  --dark1:#070e1a;
  --dark2:#0f1f35;
  --dark3:#152744;
  --card-bg:rgba(255,255,255,.04);
  --card-border:rgba(59,172,255,.12);
  --radius:14px;
  --section-py:100px 0;
}

/* ---------- Reusable ---------- */
.container{max-width:1280px;margin:0 auto;padding:0 24px}
.section-title{
  text-align:center;margin-bottom:56px;
}
.section-title h2{
  font-size:clamp(26px,3.2vw,40px);
  font-weight:700;
  background:linear-gradient(135deg,#fff 30%,var(--primary));
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
  letter-spacing:.5px;
}
.section-title .sub{
  display:inline-block;margin-top:10px;
  font-size:14px;color:#7ea4c8;letter-spacing:2px;
  border-bottom:2px solid var(--primary);padding-bottom:4px;
}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:14px 36px;border-radius:50px;font-size:15px;font-weight:600;
  cursor:pointer;border:none;transition:.3s;
}
.btn-primary{
  background:linear-gradient(135deg,var(--primary),#60c8ff);
  color:#070e1a;box-shadow:0 6px 28px rgba(59,172,255,.35);
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 10px 36px rgba(59,172,255,.45)}
.btn-outline{
  background:transparent;
  border:1.5px solid rgba(255,255,255,.25);
  color:#fff;
}
.btn-outline:hover{border-color:var(--primary);color:var(--primary)}

/* glass card */
.glass{
  background:var(--card-bg);
  border:1px solid var(--card-border);
  backdrop-filter:blur(12px);
  border-radius:var(--radius);
  transition:transform .35s,box-shadow .35s,border-color .35s;
}
.glass:hover{
  transform:translateY(-6px);
  box-shadow:0 18px 48px rgba(59,172,255,.12);
  border-color:rgba(59,172,255,.3);
}

/* scroll reveal */
.reveal{opacity:0;transform:translateY(40px);transition:opacity .7s ease,transform .7s ease}
.reveal.show{opacity:1;transform:translateY(0)}

/* ========== HEADER ========== */
.header{
  position:fixed;top:0;left:0;width:100%;z-index:999;
  background:rgba(7,14,26,.82);
  backdrop-filter:blur(16px);
  border-bottom:1px solid rgba(255,255,255,.06);
  transition:box-shadow .3s;
}
.header.scrolled{box-shadow:0 4px 30px rgba(0,0,0,.5)}
.header .inner{
  max-width:1280px;margin:0 auto;
  padding:0 24px;height:72px;
  display:flex;align-items:center;justify-content:space-between;
}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:20px;color:#fff}
.logo .icon{
  width:38px;height:38px;border-radius:10px;
  background:linear-gradient(135deg,var(--primary),#60c8ff);
  display:grid;place-items:center;color:#070e1a;font-size:18px;font-weight:900;
}
.nav{display:flex;align-items:center;gap:6px}
.nav a{
  padding:8px 16px;border-radius:8px;font-size:14px;font-weight:500;
  color:#a8bfd9;transition:.25s;
}
.nav a:hover,.nav a.active{color:#fff;background:rgba(59,172,255,.1)}
.header-phone{
  display:flex;align-items:center;gap:8px;
  font-size:14px;font-weight:600;color:var(--primary);
}
.header-phone svg{width:18px;height:18px}
/* hamburger */
.hamburger{display:none;cursor:pointer;flex-direction:column;gap:5px;padding:6px}
.hamburger span{display:block;width:22px;height:2px;background:#ccc;border-radius:2px;transition:.3s}
@media(max-width:900px){
  .hamburger{display:flex}
  .nav{
    position:fixed;top:72px;right:0;width:260px;height:calc(100vh - 72px);
    background:rgba(12,22,42,.97);backdrop-filter:blur(20px);
    flex-direction:column;padding:20px;gap:4px;
    transform:translateX(100%);transition:transform .35s ease;
    border-left:1px solid rgba(255,255,255,.06);
  }
  .nav.open{transform:translateX(0)}
  .nav a{padding:12px 16px;border-radius:10px;font-size:15px}
}

/* ========== HERO BANNER ========== */
.hero{
  position:relative;
  min-height:100vh;display:flex;align-items:center;
  background:
    radial-gradient(ellipse at 20% 50%,rgba(59,172,255,.12) 0%,transparent 60%),
    radial-gradient(ellipse at 80% 30%,rgba(245,166,35,.07) 0%,transparent 50%),
    linear-gradient(165deg,#050b15 0%,#0c1e38 40%,#0a1628 100%);
  overflow:hidden;padding-top:72px;
}
/* animated grid bg */
.hero::before{
  content:'';position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(59,172,255,.04) 1px,transparent 1px),
    linear-gradient(90deg,rgba(59,172,255,.04) 1px,transparent 1px);
  background-size:60px 60px;
  mask-image:radial-gradient(ellipse 70% 60% at 50% 50%,black,transparent);
  -webkit-mask-image:radial-gradient(ellipse 70% 60% at 50% 50%,black,transparent);
}
/* glow orb */
.hero .orb{
  position:absolute;width:420px;height:420px;border-radius:50%;
  background:radial-gradient(circle,rgba(59,172,255,.18),transparent 70%);
  top:15%;right:8%;filter:blur(60px);pointer-events:none;
  animation:orbFloat 8s ease-in-out infinite alternate;
}
@keyframes orbFloat{0%{transform:translate(0,0) scale(1)}100%{transform:translate(-30px,30px) scale(1.1)}}
.hero .container{position:relative;z-index:2}
.hero-badge{
  display:inline-flex;align-items:center;gap:8px;
  padding:6px 18px;border-radius:50px;
  background:rgba(59,172,255,.1);border:1px solid rgba(59,172,255,.2);
  font-size:13px;color:var(--primary);letter-spacing:1px;margin-bottom:22px;
}
.hero-badge .dot{width:7px;height:7px;border-radius:50%;background:var(--primary);animation:pulse 1.5s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.3}}
.hero h1{
  font-size:clamp(32px,5.5vw,64px);font-weight:800;line-height:1.15;color:#fff;
  margin-bottom:20px;
}
.hero h1 em{
  font-style:normal;
  background:linear-gradient(90deg,var(--primary),#60c8ff);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
}
.hero p{font-size:clamp(15px,1.6vw,18px);color:#8da5c4;max-width:560px;margin-bottom:36px}
.hero-actions{display:flex;flex-wrap:wrap;gap:16px}
/* floating right image silhouette */
.hero-img{
  position:absolute;right:0;bottom:0;
  width:min(52vw,720px);
  opacity:.35;pointer-events:none;
  user-select:none;
}
@media(max-width:900px){
  .hero{min-height:auto;padding-top:72px;padding-bottom:60px}
  .hero-img{display:none}
}

/* ========== SERVICES ========== */
.services{padding:var(--section-py);background:
  radial-gradient(ellipse at 50% 0%,rgba(59,172,255,.06),transparent 55%),
  var(--dark1);
}
.services-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
  gap:24px;
}
.service-card{
  padding:36px 28px;position:relative;overflow:hidden;
}
.service-card::before{
  content:'';position:absolute;top:-40px;right:-40px;
  width:120px;height:120px;border-radius:50%;
  background:radial-gradient(circle,rgba(59,172,255,.08),transparent 70%);
}
.svc-icon{
  width:56px;height:56px;border-radius:14px;
  background:linear-gradient(135deg,rgba(59,172,255,.15),rgba(59,172,255,.05));
  border:1px solid rgba(59,172,255,.18);
  display:grid;place-items:center;margin-bottom:20px;
}
.svc-icon svg{width:26px;height:26px;color:var(--primary)}
.service-card h3{font-size:17px;font-weight:650;color:#fff;margin-bottom:8px}
.service-card p{font-size:13.5px;color:#7ea4c8;line-height:1.7}

/* ========== CASES ========== */
.cases{padding:var(--section-py);background:var(--dark2)}
.cases-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(300px,1fr));
  gap:24px;
}
.case-item{
  position:relative;border-radius:var(--radius);overflow:hidden;
  aspect-ratio:16/10;
  background:var(--dark3);
}
.case-item img{width:100%;height:100%;object-fit:cover;transition:transform .5s}
.case-item:hover img{transform:scale(1.06)}
.case-overlay{
  position:absolute;inset:0;
  background:linear-gradient(to top,rgba(7,14,26,.88) 0%,transparent 55%);
  display:flex;flex-direction:column;justify-content:flex-end;
  padding:24px;transition:.3s;
}
.case-overlay h4{font-size:16px;font-weight:600;color:#fff}
.case-overlay span{font-size:12.5px;color:var(--primary);margin-top:4px}
/* placeholder "image" with gradient when no real pic */
.case-placeholder{
  width:100%;height:100%;
  background:linear-gradient(135deg,#0f1f35 0%,#1a3358 100%);
  display:grid;place-items:center;
}
.case-placeholder svg{width:48px;height:48px;color:rgba(59,172,255,.25)}

/* ========== ABOUT ========== */
.about{padding:var(--section-py);background:
  radial-gradient(ellipse at 80% 100%,rgba(245,166,35,.05),transparent 50%),
  var(--dark1);
}
.about-grid{
  display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;
}
.about-visual{
  position:relative;border-radius:var(--radius);overflow:hidden;
  aspect-ratio:4/3;
  background:linear-gradient(145deg,#0f1f35,#1a3a62);
  display:grid;place-items:center;
}
.about-visual .decor-ring{
  width:220px;height:220px;border-radius:50%;
  border:2px solid rgba(59,172,255,.15);
  display:grid;place-items:center;
}
.about-visual .decor-ring .inner{
  width:140px;height:140px;border-radius:50%;
  border:2px solid rgba(59,172,255,.25);
  display:grid;place-items:center;
  font-size:42px;color:rgba(59,172,255,.35);
}
.about-text h2{
  font-size:clamp(24px,2.8vw,36px);font-weight:700;color:#fff;margin-bottom:18px;
  line-height:1.3;
}
.about-text h2 em{font-style:normal;color:var(--primary)}
.about-text p{font-size:15px;color:#8da5c4;margin-bottom:16px}
.about-stats{display:flex;gap:36px;margin-top:28px;flex-wrap:wrap}
.about-stats .stat strong{display:block;font-size:28px;font-weight:800;color:var(--primary)}
.about-stats .stat span{font-size:13px;color:#7ea4c8}
@media(max-width:860px){
  .about-grid{grid-template-columns:1fr;gap:36px}
  .about-visual{aspect-ratio:16/9}
}

/* ========== FOOTER ========== */
.footer{
  background:#040a14;
  border-top:1px solid rgba(255,255,255,.05);
  padding:64px 0 0;
}
.footer-grid{
  display:grid;
  grid-template-columns:1.6fr 1fr 1.2fr;
  gap:48px;
}
.footer h4{font-size:15px;font-weight:650;color:#fff;margin-bottom:18px;position:relative;padding-bottom:10px}
.footer h4::after{
  content:'';position:absolute;left:0;bottom:0;
  width:28px;height:2px;background:var(--primary);border-radius:2px;
}
.footer p,.footer li{font-size:13.5px;color:#7a96b8;line-height:2}
.footer li::before{content:'›';margin-right:6px;color:var(--primary)}
.footer a:hover{color:var(--primary)}
/* qr block */
.qr-block{
  display:flex;align-items:center;gap:16px;margin-top:14px;
}
.qr-box{
  width:100px;height:100px;border-radius:12px;
  background:#fff;
  display:grid;place-items:center;
  /* 模拟二维码占位 */
  position:relative;overflow:hidden;
}
.qr-box::before{
  content:'';position:absolute;inset:8px;
  background:
    repeating-conic-gradient(#333 0% 25%,#fff 0% 50%) 0 0 / 8px 8px;
  border-radius:4px;
}
.qr-box::after{
  content:'微信二维码';position:absolute;bottom:6px;left:0;right:0;
  text-align:center;font-size:9px;color:#999;background:rgba(255,255,255,.85);line-height:1.4;
}
.qr-tip{font-size:12.5px;color:#7a96b8}
.footer-bottom{
  margin-top:48px;padding:18px 0;
  text-align:center;font-size:12.5px;color:#4e6385;
  border-top:1px solid rgba(255,255,255,.05);
}
@media(max-width:860px){
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px}
}
@media(max-width:540px){
  .footer-grid{grid-template-columns:1fr;gap:28px}
}

/* back-to-top */
.back-top{
  position:fixed;bottom:28px;right:28px;z-index:998;
  width:44px;height:44px;border-radius:50%;
  background:var(--dark3);border:1px solid var(--card-border);
  display:grid;place-items:center;cursor:pointer;
  opacity:0;pointer-events:none;transition:.35s;
  color:var(--primary);
}
.back-top.show{opacity:1;pointer-events:auto}
.back-top svg{width:20px;height:20px}