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

:root {
  --primary: #1a3a5c;
  --primary-dark: #0f2640;
  --accent: #e8843a;
  --accent-hover: #d4732a;
  --light: #f5f5f5;
  --white: #ffffff;
  --text: #333333;
  --text-light: #666666;
  --border: #e0e0e0;
  --shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.12);
  --radius: 8px;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

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

ul {
  list-style: none;
}

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

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--white);
  box-shadow: 0 1px 0 var(--border);
  transition: box-shadow var(--transition);
}

.navbar.scrolled {
  box-shadow: var(--shadow);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  white-space: nowrap;
}

.logo img {
  height: 44px;
  width: auto;
  flex-shrink: 0;
}

.logo-text {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  transition: color var(--transition);
  position: relative;
  padding: 4px 0;
}

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

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

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

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

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--primary);
  transition: var(--transition);
}

/* ===== Banner ===== */
.banner {
  position: relative;
  margin-top: 70px;
  height: 520px;
  overflow: hidden;
  background: var(--primary-dark);
}

.banner-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 1s ease-in-out;
}

.banner-slide.active {
  opacity: 1;
}

.banner-slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.banner-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(15, 38, 64, 0.75) 0%, rgba(15, 38, 64, 0.3) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.banner-content {
  color: var(--white);
  max-width: 700px;
  padding: 0 20px;
}

.banner-content h1 {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.banner-content p {
  font-size: 18px;
  opacity: 0.9;
  line-height: 1.8;
}

.banner-dots {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
}

.banner-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  cursor: pointer;
  transition: var(--transition);
  border: none;
}

.banner-dot.active {
  background: var(--accent);
}

/* ===== 区块通用 ===== */
.section {
  padding: 80px 0;
}

.section-gray {
  background: var(--light);
}

.section-title {
  text-align: center;
  margin-bottom: 48px;
}

.section-title h2 {
  font-size: 32px;
  color: var(--primary);
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  display: block;
  width: 50px;
  height: 3px;
  background: var(--accent);
  margin: 12px auto 0;
  border-radius: 2px;
}

.section-title p {
  color: var(--text-light);
  font-size: 15px;
}

/* ===== 公司简介（首页） ===== */
.about-preview {
  display: flex;
  gap: 48px;
  align-items: center;
}

.about-preview-text {
  flex: 1;
}

.about-preview-text h3 {
  font-size: 24px;
  color: var(--primary);
  margin-bottom: 16px;
}

.about-preview-text p {
  color: var(--text-light);
  margin-bottom: 12px;
  line-height: 1.8;
}

.about-preview-text .btn {
  margin-top: 8px;
}

.about-preview-image {
  flex: 1;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.about-preview-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ===== 产品卡片 ===== */
.product-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.product-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
  cursor: pointer;
  text-align: center;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.product-card-img {
  width: 100%;
  height: 220px;
  overflow: hidden;
  background: #f0f4f8;
}

.product-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.product-card:hover .product-card-img img {
  transform: scale(1.05);
}

.product-card-body {
  padding: 20px 16px;
}

.product-card-body h4 {
  font-size: 16px;
  color: var(--primary);
  font-weight: 600;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 4px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.btn-primary {
  background: var(--accent);
  color: var(--white);
  border: none;
}

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

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

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

/* ===== 企业优势（关于我们页） ===== */
.advantage-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.adv-item {
  padding: 32px 16px;
}

.adv-icon {
  width: 60px;
  height: 60px;
  background: rgba(232,132,58,0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 24px;
}

.adv-item h4 {
  color: var(--primary);
  margin-bottom: 8px;
}

.adv-item p {
  color: var(--text-light);
  font-size: 14px;
}

/* ===== 公司实力 ===== */
.strength-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.strength-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  height: 240px;
}

.strength-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.strength-item:hover img {
  transform: scale(1.08);
}

.strength-item .strength-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 16px;
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.75));
  color: var(--white);
  font-size: 15px;
  font-weight: 500;
}

/* ===== 页脚 ===== */
.footer {
  background: var(--primary-dark);
  color: rgba(255, 255, 255, 0.8);
  padding: 48px 0 24px;
}

.footer-content {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.footer-col {
  flex: 1;
  min-width: 200px;
}

.footer-col h4 {
  color: var(--white);
  font-size: 17px;
  margin-bottom: 16px;
  position: relative;
  padding-bottom: 10px;
}

.footer-col h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background: var(--accent);
}

.footer-col p,
.footer-col li {
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.8;
}

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

.footer-col-contact {
  flex: 1.5;
}

.contact-row {
  display: flex;
  align-items: flex-start;
  gap: 24px;
}

.contact-detail {
  flex: 1;
}

.contact-detail p {
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.8;
}

.footer-qr {
  width: 140px;
  height: 140px;
  object-fit: contain;
  background: #fff;
  padding: 4px;
  border-radius: 4px;
  flex-shrink: 0;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
}

/* ===== 页面头部（About/Contact等） ===== */
.page-header {
  margin-top: 70px;
  padding: 60px 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  text-align: center;
  color: var(--white);
}

.page-header h1 {
  font-size: 36px;
  margin-bottom: 12px;
}

.page-header p {
  font-size: 16px;
  opacity: 0.85;
}

/* ===== 关于我们页面 ===== */
.about-content {
  display: flex;
  gap: 48px;
  align-items: flex-start;
}

.about-text {
  flex: 1;
}

.about-text h3 {
  font-size: 22px;
  color: var(--primary);
  margin-bottom: 16px;
  margin-top: 32px;
}

.about-text h3:first-child {
  margin-top: 0;
}

.about-text p {
  color: var(--text-light);
  margin-bottom: 12px;
  line-height: 1.9;
}

.about-text ul {
  padding-left: 0;
  margin-bottom: 16px;
}

.about-text ul li {
  padding: 6px 0;
  color: var(--text-light);
  position: relative;
  padding-left: 20px;
}

.about-text ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 14px;
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
}

.about-image {
  flex: 1;
  position: sticky;
  top: 90px;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.about-image img {
  width: 100%;
}

/* ===== 联系方式卡片 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.contact-card {
  background: var(--white);
  padding: 36px 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-align: center;
  transition: transform var(--transition);
}

.contact-card:hover {
  transform: translateY(-4px);
}

.contact-card-icon {
  width: 56px;
  height: 56px;
  background: rgba(232, 132, 58, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 22px;
}

.contact-card h4 {
  color: var(--primary);
  margin-bottom: 8px;
  font-size: 17px;
}

.contact-card p {
  color: var(--text-light);
  font-size: 15px;
}

/* ===== 产品详情弹窗 ===== */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  z-index: 1100;
  align-items: center;
  justify-content: center;
}

.modal-overlay.open {
  display: flex;
}

.modal {
  background: var(--white);
  border-radius: var(--radius);
  max-width: 800px;
  width: 90%;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  position: relative;
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--white);
  border: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  z-index: 10;
}

.modal-close:hover {
  background: var(--light);
}

.modal-img {
  width: 100%;
  height: 360px;
  overflow: hidden;
  background: #f0f4f8;
}

.modal-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.modal-body {
  padding: 32px;
}

.modal-body h2 {
  font-size: 24px;
  color: var(--primary);
  margin-bottom: 16px;
}

.modal-body p {
  color: var(--text-light);
  line-height: 1.9;
  margin-bottom: 12px;
}

.modal-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 24px;
}

.modal-gallery img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  border-radius: 4px;
  cursor: pointer;
  transition: transform var(--transition);
}

.modal-gallery img:hover {
  transform: scale(1.05);
}

/* ===== 产品筛选 ===== */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-bottom: 36px;
}

.filter-btn {
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--white);
  color: var(--text);
  font-size: 14px;
  cursor: pointer;
  transition: var(--transition);
}

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

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .product-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .banner {
    height: 360px;
  }

  .banner-content h1 {
    font-size: 26px;
  }

  .banner-content p {
    font-size: 15px;
  }

  .nav-links {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    gap: 0;
    box-shadow: var(--shadow);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition);
  }

  .nav-links.open {
    max-height: 300px;
  }

  .nav-links a {
    padding: 14px 20px;
    border-bottom: 1px solid var(--border);
  }

  .menu-toggle {
    display: flex;
  }

  .product-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .about-preview,
  .about-content {
    flex-direction: column;
  }

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

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

  .section {
    padding: 48px 0;
  }

  .section-title h2 {
    font-size: 26px;
  }

  .footer-content {
    flex-direction: column;
    gap: 24px;
  }

  .contact-row {
    flex-direction: column;
    align-items: center;
  }

  .logo-text {
    font-size: 14px;
  }

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

@media (max-width: 480px) {
  .product-grid {
    grid-template-columns: 1fr;
  }

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

  .banner-content h1 {
    font-size: 22px;
  }
}