:root {
  --primary: #1a4b8c;
  --primary-dark: #0f3060;
  --primary-light: #2d6cb5;
  --accent: #e8913a;
  --accent-light: #f5b563;
  --text: #1c2d42;
  --text-muted: #5c6f85;
  --bg: #f4f7fb;
  --white: #ffffff;
  --border: #dce4ef;
  --shadow: 0 4px 24px rgba(26, 75, 140, 0.08);
  --shadow-lg: 0 12px 48px rgba(26, 75, 140, 0.14);
  --radius: 12px;
  --transition: 0.3s ease;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.header.scrolled {
  box-shadow: var(--shadow);
  border-bottom-color: transparent;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--primary-dark);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -1px;
  box-shadow: 0 4px 12px rgba(26, 75, 140, 0.25);
}

.nav {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav a {
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: var(--transition);
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}

.nav a:hover,
.nav a.active {
  color: var(--primary);
}

.nav a:hover::after,
.nav a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: var(--transition);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(145deg, #0a1e3d 0%, #1a4b8c 45%, #2d6cb5 100%);
  overflow: hidden;
  padding-top: 72px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  opacity: 0.2;
  background-image:
    radial-gradient(circle at 15% 85%, rgba(232, 145, 58, 0.35) 0%, transparent 45%),
    radial-gradient(circle at 85% 15%, rgba(255, 255, 255, 0.15) 0%, transparent 40%);
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
}

.hero-routes {
  position: absolute;
  inset: 0;
  opacity: 0.12;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 800 600'%3E%3Cpath d='M50 300 Q200 100 400 300 T750 300' fill='none' stroke='%23e8913a' stroke-width='2' stroke-dasharray='8 6'/%3E%3Cpath d='M50 400 Q250 200 450 400 T750 380' fill='none' stroke='%23ffffff' stroke-width='1.5' stroke-dasharray='6 8'/%3E%3Ccircle cx='200' cy='180' r='4' fill='%23e8913a'/%3E%3Ccircle cx='400' cy='300' r='4' fill='%23e8913a'/%3E%3Ccircle cx='600' cy='220' r='4' fill='%23e8913a'/%3E%3Ccircle cx='750' cy='300' r='4' fill='%23ffffff'/%3E%3C/svg%3E");
  background-size: cover;
  background-position: center;
}

.hero-content {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  padding: 80px 0;
}

.hero-text h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  color: white;
  line-height: 1.3;
  margin-bottom: 20px;
  font-weight: 700;
}

.hero-text h1 span {
  color: var(--accent-light);
}

.hero-text p {
  color: rgba(255, 255, 255, 0.88);
  font-size: 1.1rem;
  margin-bottom: 32px;
  max-width: 520px;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 36px;
}

.badge {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(232, 145, 58, 0.35);
  color: white;
  padding: 6px 16px;
  border-radius: 6px;
  font-size: 0.85rem;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

.btn-primary {
  background: var(--accent);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(232, 145, 58, 0.45);
}

.btn-outline {
  background: transparent;
  color: white;
  border: 2px solid rgba(255, 255, 255, 0.45);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: white;
}

.hero-visual {
  position: relative;
}

.hero-card {
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 16px;
  padding: 40px;
  color: white;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.stat-item {
  text-align: center;
  padding: 20px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.stat-num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-light);
  line-height: 1;
  margin-bottom: 6px;
}

.stat-label {
  font-size: 0.85rem;
  opacity: 0.85;
}

/* Section common */
section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 60px;
}

.section-tag {
  display: inline-block;
  background: rgba(26, 75, 140, 0.08);
  color: var(--primary);
  padding: 6px 16px;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
  border: 1px solid rgba(26, 75, 140, 0.12);
}

.section-header h2 {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  color: var(--text);
  margin-bottom: 16px;
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* About */
.about {
  background: var(--white);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-image {
  position: relative;
}

.about-image-main {
  background: linear-gradient(145deg, var(--primary-dark), var(--primary), var(--primary-light));
  border-radius: 16px;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.about-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
}

.trade-ring {
  position: absolute;
  width: 280px;
  height: 280px;
  border: 2px dashed rgba(232, 145, 58, 0.4);
  border-radius: 50%;
  animation: spin 30s linear infinite;
}

.trade-ring--inner {
  width: 200px;
  height: 200px;
  border-style: solid;
  border-color: rgba(255, 255, 255, 0.15);
  animation-direction: reverse;
  animation-duration: 20s;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.about-icon-large {
  font-size: 5rem;
  position: relative;
  z-index: 1;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.2));
}

.about-float-card {
  position: absolute;
  bottom: -20px;
  right: -20px;
  background: white;
  padding: 20px 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border-left: 4px solid var(--accent);
}

.about-float-card strong {
  display: block;
  font-size: 1.5rem;
  color: var(--primary);
}

.about-float-card span {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.about-content h3 {
  font-size: 1.6rem;
  margin-bottom: 20px;
  color: var(--primary-dark);
}

.about-content p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

.about-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 28px;
}

.about-feature {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.feature-icon {
  width: 40px;
  height: 40px;
  background: rgba(26, 75, 140, 0.08);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
  border: 1px solid rgba(26, 75, 140, 0.1);
}

.feature-text strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.feature-text span {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Services */
.services {
  background: var(--bg);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px 28px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  border: 1px solid var(--border);
  border-top: 3px solid transparent;
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-top-color: var(--accent);
  border-color: rgba(26, 75, 140, 0.15);
}

.service-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
}

.service-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  color: var(--text);
}

.service-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Products */
.products {
  background: var(--white);
}

.products-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 10px 24px;
  border: 2px solid var(--border);
  background: transparent;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: var(--transition);
  font-family: inherit;
}

.tab-btn.active,
.tab-btn:hover {
  border-color: var(--primary);
  background: var(--primary);
  color: white;
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.product-card {
  background: var(--bg);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  border: 1px solid var(--border);
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: rgba(26, 75, 140, 0.2);
}

.product-img {
  height: 160px;
  background: linear-gradient(135deg, #e8eef6, #d4e0f0);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
}

.product-card[data-category="electronic"] .product-img {
  background: linear-gradient(135deg, #e3ecf8, #c8daf0);
}

.product-card[data-category="computer"] .product-img {
  background: linear-gradient(135deg, #e8edf5, #d0d9ea);
}

.product-card[data-category="material"] .product-img {
  background: linear-gradient(135deg, #f0ebe3, #e0d5c8);
}

.product-card[data-category="daily"] .product-img {
  background: linear-gradient(135deg, #f5eef0, #e8dce0);
}

.product-info {
  padding: 20px;
}

.product-info h4 {
  font-size: 1rem;
  margin-bottom: 8px;
  color: var(--primary-dark);
}

.product-info p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Advantages */
.advantages {
  background: linear-gradient(145deg, var(--primary-dark) 0%, var(--primary) 60%, var(--primary-light) 100%);
  color: white;
  position: relative;
  overflow: hidden;
}

.advantages::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Cpath d='M0 50 L100 50 M50 0 L50 100' stroke='rgba(255,255,255,0.03)' stroke-width='0.5'/%3E%3C/svg%3E");
  background-size: 40px 40px;
}

.advantages .container {
  position: relative;
  z-index: 1;
}

.advantages .section-tag {
  background: rgba(232, 145, 58, 0.2);
  color: var(--accent-light);
  border-color: rgba(232, 145, 58, 0.3);
}

.advantages .section-header h2 {
  color: white;
}

.advantages .section-header p {
  color: rgba(255, 255, 255, 0.8);
}

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}

.advantage-item {
  text-align: center;
  padding: 32px 20px;
  background: rgba(255, 255, 255, 0.07);
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.12);
  transition: var(--transition);
}

.advantage-item:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-4px);
  border-color: rgba(232, 145, 58, 0.3);
}

.advantage-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.advantage-item h4 {
  font-size: 1.05rem;
  margin-bottom: 10px;
}

.advantage-item p {
  font-size: 0.85rem;
  opacity: 0.85;
  line-height: 1.6;
}

/* News */
.news {
  background: var(--bg);
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.news-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  border: 1px solid var(--border);
}

.news-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.news-date {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: white;
  padding: 16px 24px;
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.news-date .day {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent-light);
}

.news-date .month {
  font-size: 0.85rem;
  opacity: 0.9;
}

.news-body {
  padding: 24px;
}

.news-body h4 {
  font-size: 1.05rem;
  margin-bottom: 10px;
  line-height: 1.5;
  color: var(--primary-dark);
}

.news-body p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.news-link {
  color: var(--primary);
  font-size: 0.9rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.news-link:hover {
  gap: 8px;
  color: var(--accent);
}

/* Contact */
.contact {
  background: var(--white);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 60px;
}

.contact-info h3 {
  font-size: 1.6rem;
  margin-bottom: 16px;
  color: var(--primary-dark);
}

.contact-info > p {
  color: var(--text-muted);
  margin-bottom: 32px;
}

.contact-items {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.contact-item-icon {
  width: 48px;
  height: 48px;
  background: rgba(26, 75, 140, 0.08);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
  border: 1px solid rgba(26, 75, 140, 0.1);
}

.contact-item-text strong {
  display: block;
  margin-bottom: 4px;
}

.contact-item-text span {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.contact-item-text a {
  color: var(--primary);
  transition: var(--transition);
}

.contact-item-text a:hover {
  color: var(--accent);
}

.contact-form {
  background: var(--bg);
  padding: 40px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
  background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 75, 140, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

/* Footer */
.footer {
  background: #0a1628;
  color: rgba(255, 255, 255, 0.7);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-brand .logo {
  color: white;
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 0.9rem;
  line-height: 1.8;
  margin-bottom: 20px;
}

.footer-social {
  display: flex;
  gap: 12px;
}

.social-link {
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  font-size: 0.9rem;
}

.social-link:hover {
  background: var(--accent);
  color: white;
}

.footer-col h4 {
  color: white;
  font-size: 1rem;
  margin-bottom: 20px;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  font-size: 0.9rem;
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--accent-light);
}

.footer-bottom {
  padding: 24px 0;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
  font-size: 0.85rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.55);
}

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1.2rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--accent);
  transform: translateY(-3px);
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-text p {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-badges,
  .hero-actions {
    justify-content: center;
  }

  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .products-grid,
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .news-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    box-shadow: var(--shadow);
    border-bottom: 1px solid var(--border);
  }

  .nav.open {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .services-grid,
  .products-grid,
  .advantages-grid,
  .news-grid {
    grid-template-columns: 1fr;
  }

  .about-features {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  section {
    padding: 60px 0;
  }

  .about-float-card {
    right: 0;
    bottom: -16px;
  }
}