/* ============================================
   睿联信科技 — 企业官网 全局样式
   设计系统：科技蓝 + 工业灰，现代简约工业风
   ============================================ */

/* === CSS Variables === */
:root {
  --primary: #1a56db;
  --primary-dark: #1e429f;
  --primary-light: #e8f0fe;
  --dark: #1e293b;
  --gray: #64748b;
  --light-gray: #f1f5f9;
  --border: #e2e8f0;
  --success: #16a34a;
  --warning: #f59e0b;
  --accent: #0ea5e9;
  --white: #ffffff;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.12);
  --font-cn: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --font-en: "Inter", system-ui, -apple-system, sans-serif;
  --max-width: 1280px;
  --header-height: 72px;
  --transition: 0.25s ease;
}

/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-cn);
  color: var(--dark);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

img { max-width: 100%; height: auto; display: block; }

ul { list-style: none; }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* === Typography === */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.3; color: var(--dark); }
h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.2rem; }

.section-title {
  text-align: center;
  margin-bottom: 48px;
}
.section-title h2 {
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}
.section-title h2::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--primary);
  margin: 12px auto 0;
  border-radius: 2px;
}
.section-title p {
  color: var(--gray);
  font-size: 1.05rem;
}

/* === Header === */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: box-shadow var(--transition);
}
.header.scrolled { box-shadow: var(--shadow); }

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo { display: flex; align-items: center; gap: 10px; }
.logo img { height: 40px; width: auto; }
.logo span { font-size: 1.25rem; font-weight: 700; color: var(--dark); }

.nav { display: flex; align-items: center; gap: 32px; }
.nav a {
  color: var(--gray);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}
.nav a:hover, .nav a.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.nav-cta {
  background: var(--primary) !important;
  color: var(--white) !important;
  padding: 10px 24px !important;
  border-radius: 50px !important;
  border: none !important;
  font-weight: 600 !important;
  transition: background var(--transition), transform var(--transition) !important;
}
.nav-cta:hover {
  background: var(--primary-dark) !important;
  transform: translateY(-1px);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--dark);
  margin: 5px 0;
  transition: var(--transition);
  border-radius: 2px;
}

/* === Footer === */
.footer {
  background: var(--dark);
  color: #94a3b8;
  padding: 64px 0 32px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer h4 { color: var(--white); margin-bottom: 16px; font-size: 1rem; }
.footer a { color: #94a3b8; font-size: 0.9rem; }
.footer a:hover { color: var(--white); }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--primary);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}
.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
}
.btn-lg { padding: 16px 36px; font-size: 1.05rem; }

/* === Hero === */
.hero {
  padding: calc(var(--header-height) + 80px) 0 80px;
  background: linear-gradient(135deg, #f0f5ff 0%, #e8f0fe 50%, #f8fafc 100%);
  text-align: center;
}
.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--dark);
}
.hero h1 span { color: var(--primary); }
.hero p {
  font-size: 1.2rem;
  color: var(--gray);
  max-width: 640px;
  margin: 0 auto 32px;
}
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* === Cards === */
.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all var(--transition);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-light);
}

.card-icon {
  width: 52px;
  height: 52px;
  background: var(--primary-light);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  font-size: 1.5rem;
}

.card-grid { display: grid; gap: 24px; }

/* === Stats Bar === */
.stats-bar {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  padding: 48px 0;
  color: var(--white);
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  text-align: center;
}
.stat-number { font-size: 2.5rem; font-weight: 800; font-family: var(--font-en); }
.stat-label { font-size: 0.95rem; opacity: 0.85; margin-top: 4px; }

/* === Brand / Product Grid === */
.brand-grid, .product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 20px;
}
.brand-card, .product-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: all var(--transition);
}
.brand-card:hover, .product-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.brand-card img, .product-card img {
  height: 60px;
  margin: 0 auto 12px;
  object-fit: contain;
}
.brand-card h4 { font-size: 1rem; margin-bottom: 4px; }
.brand-card .country { color: var(--gray); font-size: 0.85rem; }
.brand-card .tags { margin-top: 8px; }

.tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.8rem;
  margin: 2px;
}

/* === Product Card Specific === */
.product-card { text-align: left; }
.product-card .model { color: var(--gray); font-size: 0.85rem; margin: 4px 0; }
.product-card .brand { font-weight: 600; font-size: 0.9rem; }
.product-card .delivery {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.8rem;
  margin-top: 8px;
}
.delivery-stock { background: #dcfce7; color: var(--success); }
.delivery-order { background: #fef3c7; color: #b45309; }

/* === Filter Bar === */
.filter-bar {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 32px;
  padding: 20px;
  background: var(--light-gray);
  border-radius: var(--radius);
}
.filter-bar select, .filter-bar input {
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  background: var(--white);
  min-width: 140px;
}
.filter-bar input { flex: 1; min-width: 200px; }

/* === Article / Knowledge Card === */
.article-card {
  display: flex;
  gap: 20px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all var(--transition);
  margin-bottom: 16px;
}
.article-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.article-card .article-meta {
  color: var(--gray);
  font-size: 0.85rem;
  display: flex;
  gap: 16px;
}
.article-card .article-summary {
  color: var(--gray);
  margin-top: 8px;
  font-size: 0.95rem;
}

/* === Breadcrumb === */
.breadcrumb {
  padding: calc(var(--header-height) + 20px) 0 20px;
  font-size: 0.9rem;
  color: var(--gray);
}
.breadcrumb a { color: var(--gray); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 8px; }

/* === Page Header === */
.page-header {
  padding: calc(var(--header-height) + 40px) 0 40px;
  background: linear-gradient(135deg, #f0f5ff 0%, #f8fafc 100%);
  text-align: center;
}
.page-header h1 { margin-bottom: 8px; }
.page-header p { color: var(--gray); font-size: 1.05rem; }

/* === Content Section === */
.section { padding: 80px 0; }
.section-gray { background: var(--light-gray); }

/* === Contact Page === */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.contact-info-item {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
  padding: 16px;
  background: var(--light-gray);
  border-radius: var(--radius-sm);
}
.contact-icon {
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.form-group { margin-bottom: 20px; }
.form-group label {
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
  font-size: 0.9rem;
}
.form-group input, .form-group textarea, .form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--transition);
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}
.form-group textarea { min-height: 120px; resize: vertical; }

/* === Service Flow === */
.flow-steps {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}
.flow-step {
  text-align: center;
  position: relative;
}
.flow-step::after {
  content: '→';
  position: absolute;
  right: -12px;
  top: 20px;
  color: var(--gray);
  font-size: 1.2rem;
}
.flow-step:last-child::after { display: none; }
.flow-step .step-num {
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 12px;
  font-weight: 700;
  font-family: var(--font-en);
}
.flow-step h4 { font-size: 0.9rem; }

/* === CTA Section === */
.cta-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  padding: 64px 0;
  text-align: center;
  color: var(--white);
}
.cta-section h2 { color: var(--white); margin-bottom: 12px; }
.cta-section p { opacity: 0.9; margin-bottom: 24px; }
.cta-section .btn-primary { background: var(--white); color: var(--primary); }
.cta-section .btn-primary:hover { background: var(--light-gray); }

/* === Article Detail === */
.article-detail {
  padding: 40px 0 80px;
}
.article-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}
.article-header h1 { margin-bottom: 12px; }
.article-body { max-width: 800px; }
.article-body h2 { margin-top: 40px; margin-bottom: 16px; }
.article-body h3 { margin-top: 28px; margin-bottom: 12px; }
.article-body p { margin-bottom: 16px; }
.article-body ul, .article-body ol { margin-bottom: 16px; padding-left: 24px; }
.article-body li { margin-bottom: 8px; list-style: disc; }
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
}
.article-body th, .article-body td {
  border: 1px solid var(--border);
  padding: 10px 14px;
  text-align: left;
}
.article-body th {
  background: var(--light-gray);
  font-weight: 600;
}
.article-body blockquote {
  border-left: 4px solid var(--primary);
  padding: 12px 20px;
  margin: 20px 0;
  background: var(--light-gray);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--gray);
}
.article-toc {
  background: var(--light-gray);
  padding: 20px 24px;
  border-radius: var(--radius);
  margin-bottom: 32px;
}
.article-toc h4 { margin-bottom: 12px; }
.article-toc ol { padding-left: 20px; }
.article-toc li { margin-bottom: 4px; font-size: 0.9rem; }

/* === FAQ === */
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  overflow: hidden;
}
.faq-question {
  padding: 16px 20px;
  font-weight: 600;
  cursor: pointer;
  background: var(--white);
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}
.faq-question:hover { background: var(--light-gray); }
.faq-question::after { content: '+'; font-size: 1.3rem; color: var(--gray); }
.faq-item.open .faq-question::after { content: '−'; }
.faq-answer { padding: 0 20px 16px; color: var(--gray); display: none; }
.faq-item.open .faq-answer { display: block; }

/* === Pagination === */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 40px;
}
.pagination a, .pagination span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  transition: all var(--transition);
}
.pagination a:hover { background: var(--primary-light); border-color: var(--primary); }
.pagination .active { background: var(--primary); color: var(--white); border-color: var(--primary); }

/* === Category Tabs === */
.category-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}
.category-tabs a {
  padding: 8px 20px;
  border-radius: 50px;
  font-size: 0.9rem;
  border: 1px solid var(--border);
  color: var(--gray);
  transition: all var(--transition);
}
.category-tabs a:hover, .category-tabs a.active {
  background: var(--primary);
  color: var(--white);
  border-color: var(--primary);
}

/* === Responsive === */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .flow-steps { grid-template-columns: repeat(3, 1fr); }
  .flow-step::after { display: none; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.6rem; }
  .hero h1 { font-size: 2.2rem; }

  .nav { display: none; }
  .nav.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--white);
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
  }
  .mobile-toggle { display: block; }

  .footer-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .stat-number { font-size: 1.8rem; }

  .brand-grid, .product-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
  .filter-bar { flex-direction: column; }

  .section { padding: 48px 0; }
  .hero { padding: calc(var(--header-height) + 40px) 0 48px; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero h1 { font-size: 1.8rem; }
  .hero-btns { flex-direction: column; align-items: center; }
  .card-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .flow-steps { grid-template-columns: repeat(2, 1fr); }
  .article-card { flex-direction: column; }
}