/* ===== RESET & BASE ===== */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#0a2e5c;
  --accent:#00b4d8;
  --accent2:#0096c7;
  --light:#f0f7ff;
  --text:#222;
  --text-light:#555;
  --white:#fff;
  --shadow:0 2px 16px rgba(10,46,92,.10);
  --radius:8px;
  --transition:all .3s ease;
}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"Microsoft YaHei","PingFang SC","Helvetica Neue",Arial,sans-serif;color:var(--text);line-height:1.7;background:var(--white);overflow-x:hidden}
a{color:inherit;text-decoration:none;transition:var(--transition)}
img{max-width:100%;display:block}
ul{list-style:none}
.container{max-width:1200px;margin:0 auto;padding:0 24px}

/* ===== HEADER ===== */
.header{position:fixed;top:0;left:0;width:100%;z-index:1000;background:rgba(10,46,92,.95);backdrop-filter:blur(10px);transition:var(--transition)}
.header.scrolled{box-shadow:0 2px 20px rgba(0,0,0,.3)}
.header .container{display:flex;align-items:center;justify-content:space-between;height:70px}
.logo{display:flex;align-items:center;gap:12px;color:var(--white);font-size:1.25rem;font-weight:700}
.logo .icon{width:40px;height:40px;background:var(--accent);border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:1.3rem;color:var(--white)}
.nav{display:flex;gap:4px}
.nav a{color:rgba(255,255,255,.8);padding:8px 16px;border-radius:6px;font-size:.95rem;transition:var(--transition)}
.nav a:hover,.nav a.active{color:var(--white);background:rgba(255,255,255,.12)}
.mobile-toggle{display:none;background:none;border:none;color:var(--white);font-size:1.5rem;cursor:pointer}

/* ===== HERO ===== */
.hero{min-height:100vh;background:linear-gradient(135deg,var(--primary) 0%,#0d4a8a 50%,var(--accent2) 100%);display:flex;align-items:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;width:600px;height:600px;background:radial-gradient(circle,rgba(0,180,216,.15) 0%,transparent 70%);top:-100px;right:-100px;border-radius:50%}
.hero::after{content:'';position:absolute;width:400px;height:400px;background:radial-gradient(circle,rgba(0,180,216,.10) 0%,transparent 70%);bottom:-50px;left:10%;border-radius:50%}
.hero .container{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;position:relative;z-index:1}
.hero-text h1{font-size:2.8rem;color:var(--white);line-height:1.3;margin-bottom:20px}
.hero-text h1 span{color:var(--accent)}
.hero-text p{color:rgba(255,255,255,.8);font-size:1.1rem;margin-bottom:32px;max-width:540px}
.hero-buttons{display:flex;gap:16px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;border-radius:50px;font-size:1rem;font-weight:600;transition:var(--transition);cursor:pointer;border:none}
.btn-primary{background:var(--accent);color:var(--white)}
.btn-primary:hover{background:var(--accent2);transform:translateY(-2px);box-shadow:0 8px 24px rgba(0,180,216,.35)}
.btn-outline{background:transparent;color:var(--white);border:2px solid rgba(255,255,255,.3)}
.btn-outline:hover{border-color:var(--white);background:rgba(255,255,255,.08)}
.hero-visual{display:flex;justify-content:center;align-items:center}
.hero-cards{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.hero-card{background:rgba(255,255,255,.08);backdrop-filter:blur(12px);border:1px solid rgba(255,255,255,.12);border-radius:var(--radius);padding:24px;color:var(--white);text-align:center;transition:var(--transition)}
.hero-card:hover{transform:translateY(-4px);background:rgba(255,255,255,.14)}
.hero-card .num{font-size:2rem;font-weight:800;color:var(--accent)}
.hero-card .label{font-size:.85rem;opacity:.8;margin-top:4px}

/* ===== SECTIONS ===== */
.section{padding:80px 0}
.section-alt{background:var(--light)}
.section-title{text-align:center;margin-bottom:48px}
.section-title h2{font-size:2rem;color:var(--primary);margin-bottom:8px}
.section-title p{color:var(--text-light);font-size:1.05rem}

/* ===== FEATURES ===== */
.features-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.feature-card{background:var(--white);border-radius:var(--radius);padding:36px 28px;box-shadow:var(--shadow);transition:var(--transition);border:1px solid rgba(0,0,0,.04)}
.feature-card:hover{transform:translateY(-6px);box-shadow:0 12px 32px rgba(10,46,92,.14)}
.feature-card .icon-box{width:56px;height:56px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:1.5rem;margin-bottom:18px}
.feature-card h3{font-size:1.15rem;margin-bottom:10px;color:var(--primary)}
.feature-card p{color:var(--text-light);font-size:.92rem;line-height:1.7}

/* ===== PRODUCTS ===== */
.cat-tabs{display:flex;justify-content:center;gap:8px;margin-bottom:36px;flex-wrap:wrap}
.cat-tab{padding:10px 24px;border-radius:50px;border:2px solid #ddd;background:var(--white);font-size:.95rem;cursor:pointer;transition:var(--transition);color:var(--text-light);font-weight:500}
.cat-tab:hover,.cat-tab.active{border-color:var(--accent);color:var(--accent);background:rgba(0,180,216,.06)}
.products-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:24px}
.product-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:var(--transition);border:1px solid rgba(0,0,0,.04);cursor:pointer}
.product-card:hover{transform:translateY(-4px);box-shadow:0 12px 32px rgba(10,46,92,.14)}
.product-card .img-wrap{height:200px;overflow:hidden;position:relative;background:linear-gradient(135deg,#e8f4fd,#d4ecfa)}
.product-card .img-wrap img{width:100%;height:100%;object-fit:cover;transition:var(--transition)}
.product-card:hover .img-wrap img{transform:scale(1.05)}
.product-card .img-wrap .placeholder{display:flex;align-items:center;justify-content:center;height:100%;font-size:3rem;color:var(--accent);opacity:.4}
.product-card .card-body{padding:20px}
.product-card h3{font-size:1.05rem;color:var(--primary);margin-bottom:8px}
.product-card p{color:var(--text-light);font-size:.88rem;line-height:1.6;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.product-card .tag{display:inline-block;background:rgba(0,180,216,.08);color:var(--accent2);font-size:.78rem;padding:3px 10px;border-radius:20px;margin-top:10px;font-weight:500}

/* ===== ABOUT ===== */
.about-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.about-text h2{font-size:2rem;color:var(--primary);margin-bottom:16px}
.about-text p{color:var(--text-light);margin-bottom:16px;line-height:1.8}
.about-stats{display:grid;grid-template-columns:repeat(2,1fr);gap:20px;margin-top:32px}
.about-stat{background:var(--light);border-radius:var(--radius);padding:20px;text-align:center}
.about-stat .num{font-size:1.8rem;font-weight:800;color:var(--accent2)}
.about-stat .label{font-size:.85rem;color:var(--text-light);margin-top:4px}

/* ===== CONTACT ===== */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px}
.contact-info{display:flex;flex-direction:column;gap:24px}
.contact-item{display:flex;gap:16px;align-items:flex-start}
.contact-item .ci-icon{width:48px;height:48px;border-radius:12px;background:rgba(0,180,216,.08);display:flex;align-items:center;justify-content:center;font-size:1.3rem;flex-shrink:0}
.contact-item .ci-text h4{font-size:1rem;color:var(--primary);margin-bottom:4px}
.contact-item .ci-text p{color:var(--text-light);font-size:.92rem}
.contact-form{background:var(--white);border-radius:var(--radius);padding:36px;box-shadow:var(--shadow)}
.contact-form h3{font-size:1.3rem;color:var(--primary);margin-bottom:24px}
.form-group{margin-bottom:18px}
.form-group label{display:block;font-size:.9rem;color:var(--text);margin-bottom:6px;font-weight:500}
.form-group input,.form-group textarea{width:100%;padding:12px 16px;border:2px solid #e8ecf0;border-radius:8px;font-size:.95rem;transition:var(--transition);font-family:inherit}
.form-group input:focus,.form-group textarea:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(0,180,216,.12)}
.form-group textarea{resize:vertical;min-height:120px}
.btn-submit{width:100%;padding:14px;background:var(--primary);color:var(--white);border:none;border-radius:8px;font-size:1rem;font-weight:600;cursor:pointer;transition:var(--transition)}
.btn-submit:hover{background:#0d3f7a}

/* ===== FOOTER ===== */
.footer{background:var(--primary);color:rgba(255,255,255,.7);padding:48px 0 24px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.5fr;gap:36px;margin-bottom:36px}
.footer h4{color:var(--white);margin-bottom:16px;font-size:1rem}
.footer p{font-size:.88rem;line-height:1.8}
.footer ul li{margin-bottom:8px}
.footer ul a{font-size:.88rem;opacity:.8;transition:var(--transition)}
.footer ul a:hover{opacity:1;color:var(--accent)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:20px;text-align:center;font-size:.82rem;opacity:.6}

/* ===== PRODUCT DETAIL ===== */
.detail-hero{padding:120px 0 48px;background:linear-gradient(135deg,var(--primary),#0d4a8a);color:var(--white)}
.detail-hero h1{font-size:2.2rem;margin-bottom:8px}
.detail-hero .breadcrumb{font-size:.9rem;opacity:.7}
.detail-hero .breadcrumb a{color:var(--accent)}
.detail-content{padding:48px 0 80px}
.detail-grid{display:grid;grid-template-columns:1fr 1.2fr;gap:48px;align-items:start}
.detail-img{border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
.detail-img img{width:100%}
.detail-text h2{font-size:1.5rem;color:var(--primary);margin-bottom:16px}
.detail-text p{color:var(--text-light);line-height:1.9;margin-bottom:14px}
.detail-features{margin-top:24px}
.detail-features h3{font-size:1.15rem;color:var(--primary);margin-bottom:12px}
.detail-features ul{padding-left:0}
.detail-features ul li{padding:8px 0 8px 24px;position:relative;color:var(--text-light);font-size:.92rem}
.detail-features ul li::before{content:'';position:absolute;left:0;top:16px;width:8px;height:8px;background:var(--accent);border-radius:50%}
.back-link{display:inline-flex;align-items:center;gap:8px;color:var(--accent);font-weight:500;margin-top:24px;transition:var(--transition)}
.back-link:hover{color:var(--accent2)}

/* ===== RESPONSIVE ===== */
@media(max-width:1024px){
  .hero .container{grid-template-columns:1fr;text-align:center}
  .hero-text p{margin:0 auto 32px}
  .hero-buttons{justify-content:center}
  .hero-visual{margin-top:24px}
  .features-grid{grid-template-columns:repeat(2,1fr)}
  .about-grid,.contact-grid,.detail-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:768px){
  .nav{display:none;position:fixed;top:70px;left:0;width:100%;background:var(--primary);flex-direction:column;padding:16px}
  .nav.open{display:flex}
  .nav a{padding:12px 20px}
  .mobile-toggle{display:block}
  .hero-text h1{font-size:2rem}
  .features-grid{grid-template-columns:1fr}
  .products-grid{grid-template-columns:1fr}
  .hero-cards{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr}
  .section{padding:48px 0}
  .about-stats{grid-template-columns:1fr 1fr}
}

/* ===== ANIMATIONS ===== */
.fade-in{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.fade-in.visible{opacity:1;transform:translateY(0)}

/* ===== SCROLL TOP ===== */
.scroll-top{position:fixed;bottom:32px;right:32px;width:44px;height:44px;border-radius:50%;background:var(--accent);color:var(--white);border:none;cursor:pointer;font-size:1.2rem;display:none;align-items:center;justify-content:center;box-shadow:0 4px 12px rgba(0,180,216,.3);transition:var(--transition);z-index:999}
.scroll-top.show{display:flex}
.scroll-top:hover{transform:translateY(-3px);background:var(--accent2)}