:root{
    --blue:#2563eb;
    --cyan:#06b6d4;
    --navy:#0b1f3a;
    --ink:#1f2937;
    --muted:#64748b;
    --line:#e6ebf2;
    --bg-alt:#f5f8fc;
    --radius:16px;
    --shadow:0 18px 40px rgba(15,42,84,.10);
    --maxw:1160px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
    font-family:"PingFang SC","Microsoft YaHei","Hiragino Sans GB","Source Han Sans CN",system-ui,sans-serif;
    color:var(--ink);background:#fff;line-height:1.7;-webkit-font-smoothing:antialiased;
}
a{text-decoration:none;color:inherit}
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 22px}
img{max-width:100%}

/* 导航 */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.9);backdrop-filter:saturate(180%) blur(12px);border-bottom:1px solid var(--line);transition:.3s}
.nav.scrolled{box-shadow:0 6px 24px rgba(15,42,84,.08)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:66px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700}
.brand-mark{display:inline-flex}
.brand-text{font-size:19px;color:var(--navy);letter-spacing:.5px;display:flex;flex-direction:column;line-height:1}
.brand-text i{font-style:normal;font-size:9px;letter-spacing:2px;color:var(--cyan);font-weight:600;margin-top:3px}
.menu{display:flex;gap:30px}
.menu a{color:var(--ink);font-weight:500;position:relative;padding:6px 0;transition:.2s}
.menu a::after{content:"";position:absolute;left:0;bottom:0;width:0;height:2px;background:linear-gradient(90deg,var(--blue),var(--cyan));transition:.25s}
.menu a:hover{color:var(--blue)}
.menu a:hover::after{width:100%}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px}
.nav-toggle span{width:24px;height:2px;background:var(--navy);border-radius:2px;transition:.3s}

/* Hero */
.hero{position:relative;overflow:hidden;color:#fff;background:linear-gradient(135deg,#0b1f3a 0%,#13365f 55%,#0e4a6b 100%);padding:120px 0 150px}
.hero-bg{position:absolute;inset:0;background:
  radial-gradient(900px 400px at 80% -10%,rgba(6,182,212,.35),transparent 60%),
  radial-gradient(700px 380px at 10% 20%,rgba(37,99,235,.30),transparent 60%);
  opacity:.9}
.hero-inner{position:relative;text-align:center;z-index:2}
.hero-eyebrow{letter-spacing:3px;font-size:12px;color:#9fd6f0;margin-bottom:18px}
.hero-title{font-size:46px;font-weight:800;letter-spacing:2px;text-shadow:0 4px 30px rgba(0,0,0,.25)}
.hero-sub{font-size:20px;margin-top:14px;color:#cfe9f7;font-weight:500}
.hero-desc{margin-top:20px;font-size:16px;color:#dbeafe;line-height:2}
.hero-desc span{color:#7fd8f0;font-weight:600}
.hero-btns{margin-top:34px;display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.btn{display:inline-block;padding:13px 30px;border-radius:999px;font-weight:600;font-size:15px;transition:.25s;cursor:pointer;border:1px solid transparent}
.btn-primary{background:linear-gradient(90deg,var(--blue),var(--cyan));color:#fff;box-shadow:0 10px 26px rgba(6,182,212,.35)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 34px rgba(6,182,212,.45)}
.btn-ghost{border-color:rgba(255,255,255,.5);color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.12);transform:translateY(-2px)}
.hero-wave{position:absolute;left:0;right:0;bottom:-1px;height:60px;background:radial-gradient(120% 100% at 50% 100%,#fff 40%,transparent 41%);z-index:1}

/* 通用 section */
.section{padding:84px 0}
.section-alt{background:var(--bg-alt)}
.section-head{text-align:center;max-width:720px;margin:0 auto 48px}
.section-tag{display:inline-block;font-size:12px;letter-spacing:3px;color:var(--cyan);font-weight:700;margin-bottom:10px}
.section-head h2{font-size:32px;color:var(--navy);font-weight:800}
.section-lead{color:var(--muted);margin-top:10px;font-size:15px}

/* 关于 */
.about-grid{display:grid;grid-template-columns:1.4fr 1fr;gap:46px;align-items:center}
.about-text p{color:var(--ink);margin-bottom:14px}
.about-list{list-style:none;margin-top:18px;display:grid;gap:12px}
.about-list li{position:relative;padding-left:26px;color:var(--ink)}
.about-list li::before{content:"";position:absolute;left:0;top:9px;width:14px;height:14px;border-radius:50%;background:linear-gradient(135deg,var(--blue),var(--cyan))}
.about-stats{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.stat{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:24px;text-align:center;box-shadow:var(--shadow)}
.stat b{display:block;font-size:36px;font-weight:800;color:var(--blue);line-height:1}
.stat span{display:block;margin-top:8px;color:var(--muted);font-size:14px}

/* 业务卡片 */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:34px 28px;box-shadow:var(--shadow);transition:.28s;position:relative;overflow:hidden}
.card:hover{transform:translateY(-6px);border-color:transparent;box-shadow:0 24px 50px rgba(15,42,84,.16)}
.card-icon{width:58px;height:58px;border-radius:14px;background:linear-gradient(135deg,var(--blue),var(--cyan));display:flex;align-items:center;justify-content:center;margin-bottom:18px}
.card h3{font-size:20px;color:var(--navy);margin-bottom:12px}
.card p{color:var(--muted);font-size:14.5px;margin-bottom:16px}
.card-list{list-style:none;display:grid;gap:9px}
.card-list li{position:relative;padding-left:22px;font-size:14px;color:var(--ink)}
.card-list li::before{content:"✓";position:absolute;left:0;top:0;color:var(--cyan);font-weight:700}

/* 技术能力 */
.tech-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.tech-col{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px 26px;box-shadow:var(--shadow);transition:.28s}
.tech-col:hover{transform:translateY(-6px);box-shadow:0 24px 50px rgba(15,42,84,.16)}
.tech-head{display:flex;align-items:center;gap:13px}
.tech-ico{width:46px;height:46px;flex:0 0 auto;border-radius:13px;background:linear-gradient(135deg,var(--blue),var(--cyan));display:flex;align-items:center;justify-content:center}
.tech-col h3{font-size:19px;color:var(--navy);line-height:1.25}
.tech-col h3 i{display:block;font-style:normal;font-size:10px;letter-spacing:2px;color:var(--cyan);font-weight:700;margin-top:4px}
.tech-desc{color:var(--muted);font-size:14px;margin:14px 0 18px}
.tech-tags{display:flex;flex-wrap:wrap;gap:9px}
.tech-tags span{display:inline-flex;align-items:center;gap:7px;font-size:13.5px;font-weight:600;color:var(--navy);background:linear-gradient(180deg,#f8fbff,#eef4fc);border:1px solid #dbe7f5;border-radius:999px;padding:7px 14px;transition:.22s}
.tech-tags span::before{content:"";width:7px;height:7px;border-radius:50%;background:linear-gradient(135deg,var(--blue),var(--cyan))}
.tech-tags span:hover{color:var(--blue);border-color:var(--cyan);box-shadow:0 6px 16px rgba(6,182,212,.18);transform:translateY(-2px)}
.tech-note{margin-top:30px;text-align:center;color:var(--muted);font-size:14px}

/* 优势 */
.adv-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.adv{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px 24px;box-shadow:var(--shadow);transition:.25s}
.adv:hover{transform:translateY(-4px)}
.adv b{font-size:30px;font-weight:800;background:linear-gradient(135deg,var(--blue),var(--cyan));-webkit-background-clip:text;background-clip:text;color:transparent}
.adv h4{margin:10px 0 8px;font-size:18px;color:var(--navy)}
.adv p{color:var(--muted);font-size:14px}

/* 联系 */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:start}
.contact-info{display:grid;gap:16px}
.c-item{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px 22px;box-shadow:var(--shadow)}
.c-label{display:block;font-size:12px;color:var(--cyan);font-weight:700;letter-spacing:1px;margin-bottom:6px}
.c-value{font-size:16px;color:var(--navy);font-weight:600}
.contact-form{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow);display:grid;gap:14px}
.contact-form input,.contact-form textarea{width:100%;border:1px solid var(--line);border-radius:10px;padding:13px 15px;font-size:15px;font-family:inherit;color:var(--ink);background:#fbfdff;transition:.2s;resize:vertical}
.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--cyan);box-shadow:0 0 0 3px rgba(6,182,212,.15)}
.form-tip{font-size:12px;color:var(--muted);margin-top:2px}

/* 页脚 */
.footer{background:var(--navy);color:#cdd9e8;padding:54px 0 22px}
.footer-inner{display:flex;justify-content:space-between;flex-wrap:wrap;gap:26px;padding-bottom:26px;border-bottom:1px solid rgba(255,255,255,.12)}
.footer-brand .brand-text{color:#fff}
.footer-brand p{margin-top:12px;color:#9fb3cc;font-size:14px;max-width:320px}
.footer-links{display:flex;gap:26px;flex-wrap:wrap;align-items:center}
.footer-links a{color:#cdd9e8;font-size:14px;transition:.2s}
.footer-links a:hover{color:var(--cyan)}
.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;padding-top:18px;color:#8aa0bd;font-size:13px}
.footer-bottom a{color:#8aa0bd;border-bottom:1px dashed rgba(138,160,189,.5)}
.footer-bottom a:hover{color:var(--cyan)}

/* 返回顶部 */
.to-top{position:fixed;right:22px;bottom:22px;width:44px;height:44px;border-radius:50%;background:linear-gradient(135deg,var(--blue),var(--cyan));color:#fff;display:flex;align-items:center;justify-content:center;font-size:20px;box-shadow:0 10px 24px rgba(6,182,212,.4);opacity:0;visibility:hidden;transition:.3s;z-index:40}
.to-top.show{opacity:1;visibility:visible}

/* 响应式 */
@media(max-width:960px){
    .menu{gap:20px}
    .menu a{font-size:14.5px}
    .about-grid{grid-template-columns:1fr;gap:30px}
    .cards{grid-template-columns:1fr}
    .tech-grid{grid-template-columns:1fr}
    .adv-grid{grid-template-columns:1fr 1fr}
    .contact-grid{grid-template-columns:1fr}
}
@media(max-width:640px){
    .menu{position:fixed;top:66px;left:0;right:0;background:#fff;flex-direction:column;gap:0;padding:10px 22px 18px;border-bottom:1px solid var(--line);transform:translateY(-120%);transition:.3s;box-shadow:0 12px 30px rgba(15,42,84,.12)}
    .menu.open{transform:translateY(0)}
    .menu a{padding:12px 0;border-bottom:1px solid var(--line)}
    .menu a::after{display:none}
    .nav-toggle{display:flex}
    .hero{padding:90px 0 120px}
    .hero-title{font-size:32px}
    .hero-sub{font-size:17px}
    .section-head h2{font-size:26px}
    .adv-grid{grid-template-columns:1fr}
    .about-stats{grid-template-columns:1fr 1fr}
}