/* === LUWATECH Design System === */
:root {
  --navy: #0a1628;
  --navy-light: #132040;
  --blue: #1a5fb4;
  --blue-light: #3584e4;
  --gold: #c9a84c;
  --white: #ffffff;
  --gray-50: #f6f8fa;
  --gray-100: #eef0f4;
  --gray-200: #d5d7dd;
  --gray-300: #9a9ea8;
  --gray-500: #5a5e68;
  --gray-700: #2a2e38;
  --gray-900: #141820;
  --radius: 8px;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --max-width: 1280px;
}

/* === Reset === */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"Inter","PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;color:var(--gray-700);line-height:1.7;background:var(--white)}

/* === Typography === */
h1,h2,h3,h4,h5,h6{line-height:1.3}
a{color:var(--blue-light);text-decoration:none;transition:color .2s}
a:hover{color:var(--blue)}

/* === Header === */
header{position:fixed;top:0;left:0;right:0;z-index:100;background:var(--navy);padding:0 2rem;transition:background .3s}
.header-inner{max-width:var(--max-width);margin:0 auto;display:flex;align-items:center;justify-content:space-between;height:72px}
.logo{display:flex;align-items:center;gap:12px;text-decoration:none}
.logo-img{height:48px;width:auto;display:block}
nav{display:flex;align-items:center;gap:2rem}
nav a{color:var(--gray-200);text-decoration:none;font-size:.9rem;font-weight:500;transition:color .2s}
nav a:hover,nav a.active{color:var(--white)}
.lang-switcher{display:flex;align-items:center;gap:.35rem}
.lang-switcher a{color:var(--gray-300);text-decoration:none;font-size:.8rem;padding:4px 10px;border-radius:14px;transition:all .2s;font-weight:500}
.lang-switcher a:hover,.lang-switcher a.active{background:rgba(255,255,255,.15);color:var(--white)}
.menu-btn{display:none;background:none;border:none;color:var(--white);font-size:1.5rem;cursor:pointer}

/* === Mobile Nav === */
@media(max-width:768px){
  .logo-img{height:36px}
  nav{display:none}
  .menu-btn{display:block}
  nav.open{display:flex;position:fixed;top:72px;left:0;right:0;background:var(--navy);flex-direction:column;padding:1.5rem 2rem;gap:1rem;box-shadow:0 8px 24px rgba(0,0,0,.3)}
  .lang-switcher{gap:.25rem}
  .lang-switcher a{font-size:.75rem;padding:3px 8px}
}

/* === Hero === */
.hero{min-height:100vh;background:linear-gradient(135deg,var(--navy) 0%,#0d1f3a 50%,#132848 100%);display:flex;align-items:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%233584e4' fill-opacity='0.06'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")}
.hero-inner{max-width:var(--max-width);margin:0 auto;padding:6rem 2rem;position:relative;z-index:1}
.hero-badge{display:inline-block;background:rgba(53,132,228,.15);color:var(--blue-light);padding:6px 20px;border-radius:20px;font-size:.85rem;font-weight:600;margin-bottom:1.5rem;border:1px solid rgba(53,132,228,.3)}
.hero h1{color:var(--white);font-size:3.5rem;font-weight:800;line-height:1.2;margin-bottom:1rem;max-width:800px}
.hero h1 .highlight{color:var(--blue-light)}
.hero-sub{color:var(--gray-200);font-size:1.2rem;max-width:650px;line-height:1.8;margin-bottom:2.5rem}
.hero-cta{display:flex;gap:1rem;flex-wrap:wrap}
.hero-stats{display:flex;gap:3rem;margin-top:4rem;flex-wrap:wrap}
.stat-item{color:var(--white)}
.stat-num{font-size:2.5rem;font-weight:800;color:var(--blue-light);line-height:1}
.stat-label{color:var(--gray-300);font-size:.9rem;margin-top:.5rem}

/* === Buttons === */
.btn{padding:14px 32px;border-radius:var(--radius);font-weight:600;font-size:.95rem;cursor:pointer;transition:all .25s;text-decoration:none;display:inline-block;border:none}
.btn-primary{background:var(--blue-light);color:var(--white)}
.btn-primary:hover{background:#2979d8;transform:translateY(-2px);box-shadow:0 8px 24px rgba(53,132,228,.3);color:var(--white)}
.btn-outline{background:transparent;color:var(--white);border:2px solid rgba(255,255,255,.3)}
.btn-outline:hover{border-color:var(--white);transform:translateY(-2px);color:var(--white)}
.btn-secondary{background:transparent;color:var(--blue);border:2px solid var(--blue)}
.btn-secondary:hover{background:rgba(26,95,180,.08);color:var(--blue-light);border-color:var(--blue-light)}
.btn-sm{padding:8px 20px;font-size:.85rem}
.btn-download{background:var(--blue-light);color:#fff;padding:10px 24px;border-radius:var(--radius);font-weight:600;font-size:.9rem;display:inline-flex;align-items:center;gap:8px;transition:all .25s;text-decoration:none}
.btn-download:hover{background:#2979d8;transform:translateY(-1px);color:#fff}

/* === Sections === */
section{padding:5rem 2rem}
.section-inner{max-width:var(--max-width);margin:0 auto}
.section-tag{display:inline-block;color:var(--blue);font-weight:700;font-size:.8rem;text-transform:uppercase;letter-spacing:1px;margin-bottom:.75rem}
.section-title{font-size:2.25rem;font-weight:800;color:var(--gray-900);margin-bottom:1rem}
.section-desc{color:var(--gray-500);font-size:1.1rem;max-width:700px;margin-bottom:3rem;line-height:1.7}

@media(max-width:768px){
  .hero h1{font-size:2.25rem}
  .hero-sub{font-size:1rem}
  .hero-stats{gap:1.5rem}
  .stat-num{font-size:1.8rem}
  .section-title{font-size:1.75rem}
}

/* === About === */
.about{background:var(--gray-50)}
.about-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1.5rem;margin-top:2rem}
.about-card{background:var(--white);padding:2rem;border-radius:var(--radius);box-shadow:var(--shadow);border:1px solid var(--gray-100)}
.about-card h3{font-size:1.1rem;margin-bottom:.75rem;color:var(--gray-900);display:flex;align-items:center;gap:.5rem}
.about-card h3 .icon{color:var(--blue-light);font-size:1.3rem}
.about-card p{color:var(--gray-500);font-size:.95rem;line-height:1.7}
.values-row{display:flex;gap:2rem;flex-wrap:wrap;margin-top:2rem;justify-content:center}
.value-item{display:flex;align-items:center;gap:.5rem;font-size:1.1rem;font-weight:700;color:var(--navy)}
.value-icon{color:var(--gold);font-size:1rem}
.values-tagline{text-align:center;margin-top:1.25rem;font-size:1.3rem;font-weight:600;color:var(--blue);font-style:italic}
@media(max-width:768px){.values-row{gap:1rem}.value-item{font-size:.95rem}}

/* === Featured === */
.featured-section{margin-bottom:3rem}
.featured-header{display:flex;align-items:center;gap:.75rem;margin-bottom:1.25rem}
.featured-badge{background:var(--gold);color:var(--navy);padding:4px 14px;border-radius:20px;font-size:.8rem;font-weight:700;letter-spacing:.5px}
.featured-title{font-size:1.4rem;font-weight:800;color:var(--gray-900)}
.featured-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(360px,1fr));gap:1.25rem}
.featured-card{background:var(--white);border:2px solid var(--gray-200);border-radius:12px;overflow:hidden;cursor:pointer;transition:all .25s;display:flex;text-decoration:none;color:inherit}
.featured-card:hover{border-color:var(--gold);box-shadow:0 8px 30px rgba(201,168,76,.18);transform:translateY(-3px)}
.featured-card-img{width:180px;height:170px;object-fit:contain;background:var(--gray-50);padding:10px;flex-shrink:0}
.featured-card-body{padding:1.25rem 1.5rem;display:flex;flex-direction:column;justify-content:center}
.featured-card-model{font-size:1.3rem;font-weight:800;color:var(--gray-900);margin-bottom:4px}
.featured-card-name{font-size:.9rem;color:var(--gray-500);margin-bottom:.6rem;line-height:1.4}
.featured-card-tag{display:inline-block;background:var(--gold);color:var(--navy);font-size:.75rem;padding:3px 12px;border-radius:4px;font-weight:700}
@media(max-width:768px){
  .featured-grid{grid-template-columns:1fr}
  .featured-card{flex-direction:column}
  .featured-card-img{width:100%;height:160px}
}

/* === Products === */
.products{background:var(--white)}
.product-category{margin-bottom:3rem}
.category-header{display:flex;align-items:center;gap:1rem;margin-bottom:1.5rem;padding-bottom:.75rem;border-bottom:2px solid var(--gray-100)}
.category-icon{width:44px;height:44px;background:var(--navy);color:var(--blue-light);border-radius:var(--radius);display:flex;align-items:center;justify-content:center;font-size:1.25rem;flex-shrink:0}
.category-header h3{font-size:1.4rem;color:var(--gray-900);font-weight:700}
.category-header .count{color:var(--gray-300);font-size:.85rem;margin-left:auto}
.product-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:1rem}
.product-card{background:var(--white);border:1px solid var(--gray-100);border-radius:var(--radius);cursor:pointer;transition:all .2s;position:relative;overflow:hidden;display:flex;flex-direction:column;text-decoration:none;color:inherit}
.product-card:hover{border-color:var(--blue-light);box-shadow:0 4px 16px rgba(53,132,228,.12);transform:translateY(-2px)}
.product-card-img{width:100%;height:150px;object-fit:contain;background:var(--gray-50);padding:10px;flex-shrink:0}
.product-card-body{padding:1rem 1.25rem 1.25rem;flex:1}
.product-card .model{font-size:1.05rem;font-weight:700;color:var(--gray-900);margin-bottom:.35rem}
.product-card .name{font-size:.82rem;color:var(--gray-500);line-height:1.4}
.product-card .tag{display:inline-block;background:var(--blue-light);color:#fff;font-size:.7rem;padding:2px 8px;border-radius:4px;margin-top:.5rem;font-weight:600}
.product-card .arrow{position:absolute;right:1rem;top:50%;transform:translateY(-50%);color:var(--gray-300);font-size:1.2rem;opacity:0;transition:all .2s;z-index:1}
.product-card:hover .arrow{opacity:1;color:var(--blue-light)}

/* Product search */
.product-search{margin-bottom:2rem}
.product-search input{width:100%;max-width:400px;padding:12px 20px;border:2px solid var(--gray-200);border-radius:24px;font-size:.95rem;outline:none;transition:border-color .2s}
.product-search input:focus{border-color:var(--blue-light)}

@media(max-width:768px){.product-grid{grid-template-columns:repeat(auto-fill,minmax(160px,1fr))}}

/* === Product Detail Page === */
.product-detail{background:var(--gray-50);min-height:60vh}
.product-detail-inner{max-width:var(--max-width);margin:0 auto;padding:2rem}
.product-detail-grid{display:grid;grid-template-columns:1fr 1fr;gap:3rem;align-items:start}
.product-detail-image{background:var(--white);border-radius:12px;padding:2rem;text-align:center;border:1px solid var(--gray-100)}
.product-detail-image img{max-width:100%;max-height:400px;object-fit:contain}
.product-detail-info h1{font-size:2rem;font-weight:800;color:var(--gray-900);margin-bottom:.5rem}
.product-detail-info .model-tag{display:inline-block;background:var(--blue-light);color:#fff;padding:4px 14px;border-radius:20px;font-size:.85rem;font-weight:600;margin-bottom:1rem}
.product-detail-desc{font-size:1.05rem;color:var(--gray-500);line-height:1.8;margin-bottom:2rem}
.spec-table{width:100%;border-collapse:collapse;margin:1.5rem 0;font-size:.9rem;background:var(--white);border-radius:var(--radius);overflow:hidden;border:1px solid var(--gray-100)}
.spec-table tr:nth-child(even){background:var(--gray-50)}
.spec-table td{padding:.75rem 1rem;border-bottom:1px solid var(--gray-100)}
.spec-table td:first-child{font-weight:600;color:var(--gray-700);width:35%}
.spec-table td:last-child{color:var(--gray-500)}
.product-detail-actions{display:flex;gap:1rem;flex-wrap:wrap;margin-top:1.5rem}
.back-link{display:inline-flex;align-items:center;gap:.5rem;color:var(--gray-500);font-size:.9rem;margin-bottom:1.5rem;text-decoration:none;transition:color .2s}
.back-link:hover{color:var(--blue-light)}

@media(max-width:768px){
  .product-detail-grid{grid-template-columns:1fr}
  .product-detail-image{padding:1rem}
}

/* === Breadcrumb === */
.breadcrumb{padding:1rem 0;font-size:.85rem;color:var(--gray-300)}
.breadcrumb a{color:var(--gray-500);text-decoration:none}
.breadcrumb a:hover{color:var(--blue-light)}
.breadcrumb span{color:var(--gray-300)}
.breadcrumb .sep{margin:0 .5rem}

/* === Downloads === */
.downloads{background:var(--gray-50)}
.download-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1.5rem;margin-top:2rem}
.download-card{background:var(--white);border:1px solid var(--gray-100);border-radius:var(--radius);padding:2rem;transition:all .2s}
.download-card:hover{border-color:var(--blue-light);box-shadow:var(--shadow)}
.download-card h3{font-size:1.1rem;margin-bottom:.5rem;color:var(--gray-900)}
.download-card p{font-size:.9rem;color:var(--gray-500);margin-bottom:1rem}

/* === Contact === */
.contact{background:var(--navy);color:var(--white)}
.contact .section-tag{color:var(--blue-light)}
.contact .section-title{color:var(--white)}
.contact .section-desc{color:var(--gray-200)}
.contact-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:1.5rem;margin-top:2rem}
.contact-card{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.1);border-radius:var(--radius);padding:1.75rem}
.contact-card h4{font-size:1rem;margin-bottom:.75rem;color:var(--blue-light);display:flex;align-items:center;gap:.5rem}
.contact-card p{color:var(--gray-200);font-size:.9rem;line-height:1.7}
.contact-card a{color:var(--blue-light);text-decoration:none}

/* === Footer === */
footer{background:var(--gray-900);color:var(--gray-300);padding:3rem 2rem 2rem}
.footer-grid{display:flex;flex-wrap:wrap;gap:2rem;justify-content:space-between;align-items:flex-start;margin-bottom:1.5rem}
.footer-col{flex:1;min-width:200px}
.footer-col h4{color:var(--white);margin-bottom:.75rem;font-size:1rem}
.footer-col p,.footer-col a{font-size:.85rem;line-height:2;color:var(--gray-300);text-decoration:none}
.footer-col a:hover{color:var(--white)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:1.5rem;text-align:center;font-size:.85rem}

/* === Back to Top === */
.back-to-top{position:fixed;bottom:2rem;right:2rem;width:44px;height:44px;background:var(--blue-light);color:var(--white);border:none;border-radius:50%;cursor:pointer;font-size:1.2rem;opacity:0;transform:translateY(20px);transition:all .3s;z-index:150;pointer-events:none;box-shadow:0 4px 12px rgba(53,132,228,.3)}
.back-to-top.visible{opacity:1;transform:translateY(0);pointer-events:auto}
.back-to-top:hover{background:#2979d8;transform:translateY(-3px)}

/* === 404 === */
.not-found{text-align:center;padding:8rem 2rem;min-height:60vh;display:flex;align-items:center;justify-content:center;flex-direction:column}
.not-found h1{font-size:6rem;font-weight:800;color:var(--blue-light);line-height:1}
.not-found h2{font-size:1.5rem;color:var(--gray-900);margin:1rem 0}
.not-found p{color:var(--gray-500);margin-bottom:2rem}

/* === Page Header (for inner pages) === */
.page-header{background:var(--navy);padding:8rem 2rem 3rem;position:relative;overflow:hidden}
.page-header::before{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%233584e4' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")}
.page-header-inner{max-width:var(--max-width);margin:0 auto;position:relative;z-index:1}
.page-header h1{color:var(--white);font-size:2.5rem;font-weight:800}
.page-header .page-subtitle{color:var(--gray-300);font-size:1.1rem;margin-top:.5rem}

/* === Utilities === */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}