/* ===== 全局重置与变量 ===== */
:root {
  --primary: #00acc1;
  --primary-dark: #00838f;
  --primary-light: #e0f7fa;
  --text: #333333;
  --text-light: #666666;
  --text-muted: #999999;
  --bg: #ffffff;
  --bg-light: #f8fafb;
  --bg-dark: #1a2a33;
  --border: #e5e7eb;
  --shadow: 0 4px 20px rgba(0,0,0,0.06);
  --shadow-hover: 0 8px 30px rgba(0,0,0,0.1);
  --radius: 8px;
  --transition: all 0.3s ease;
  --max-width: 1200px;
}

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

html { scroll-behavior: smooth; }

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

a { text-decoration: none; color: inherit; transition: var(--transition); }

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

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.navbar .container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-brand img {
  height: 48px;
  width: auto;
}

.logo-brand .brand-text {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}

.logo-brand .brand-text small {
  display: block;
  font-size: 11px;
  font-weight: 400;
  color: var(--primary);
  letter-spacing: 1px;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 40px;
}

.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-light);
  position: relative;
  padding: 8px 0;
}

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

.nav-links a.active::after,
.nav-links a:hover::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
}

.mobile-menu-btn span {
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== 通用按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius);
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

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

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

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

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

.btn-lg { padding: 14px 40px; font-size: 16px; }

/* ===== 通用板块 ===== */
.section { padding: 80px 0; }

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

.section-dark { background: var(--bg-dark); color: #fff; }

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

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-header h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.section-dark .section-header h2 { color: #fff; }

.section-header p {
  font-size: 16px;
  color: var(--text-muted);
}

.section-dark .section-header p { color: rgba(255,255,255,0.6); }

.section-header .line {
  width: 48px;
  height: 3px;
  background: var(--primary);
  margin: 16px auto 0;
  border-radius: 2px;
}

/* ===== Hero Banner ===== */
.hero {
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  background: linear-gradient(135deg, #e0f7fa 0%, #ffffff 50%, #e0f7fa 100%);
  padding-top: 72px;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -100px;
  right: -100px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(0,172,193,0.1) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -150px;
  left: -100px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(0,172,193,0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 0 24px;
}

.hero-content h1 {
  font-size: 48px;
  font-weight: 800;
  margin-bottom: 20px;
  color: var(--text);
  line-height: 1.2;
}

.hero-content h1 span {
  color: var(--primary);
}

.hero-content p {
  font-size: 18px;
  color: var(--text-light);
  margin-bottom: 36px;
  line-height: 1.8;
}

.hero-btns {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== 特色卡片 ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.feature-card {
  background: #fff;
  padding: 36px 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-align: center;
  transition: var(--transition);
  border: 1px solid var(--border);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}

.feature-card .icon {
  width: 64px;
  height: 64px;
  background: var(--primary-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 28px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text);
}

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

/* ===== 产品卡片 ===== */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

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

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

.product-card .product-img-wrap {
  position: relative;
  width: 100%;
  height: 220px;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.product-card .product-img-wrap::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 28px;
  background: linear-gradient(to top, rgba(255,255,255,1), rgba(255,255,255,0.7), transparent);
  pointer-events: none;
}

.product-card .product-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 12px 12px 18px 12px;
}

.product-card .product-info {
  padding: 24px;
}

.product-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.product-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.6;
}

/* ===== 关于页面 ===== */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text h3 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--text);
}

.about-text p {
  font-size: 15px;
  color: var(--text-light);
  margin-bottom: 16px;
  line-height: 1.8;
}

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

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

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 60px;
}

.stat-item {
  text-align: center;
  padding: 32px 20px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.stat-item .num {
  font-size: 36px;
  font-weight: 800;
  color: var(--primary);
  display: block;
  margin-bottom: 8px;
}

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

/* ===== 时间线 ===== */
.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  padding-bottom: 32px;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 4px;
  width: 12px;
  height: 12px;
  background: var(--primary);
  border-radius: 50%;
  border: 3px solid #fff;
  box-shadow: 0 0 0 2px var(--primary);
}

.timeline-item .year {
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 4px;
}

.timeline-item h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

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

/* ===== 联系页面 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.contact-info h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 24px;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 24px;
}

.contact-item .icon {
  width: 44px;
  height: 44px;
  background: var(--primary-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 18px;
}

.contact-item h4 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

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

.contact-form {
  background: #fff;
  padding: 36px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

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

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 8px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0,172,193,0.1);
}

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

/* ===== 页脚 ===== */
.footer {
  background: var(--bg-dark);
  color: rgba(255,255,255,0.7);
  padding: 60px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1.9fr;
  gap: 32px;
  margin-bottom: 40px;
}

.footer-brand img {
  height: 56px;
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.8;
  color: rgba(255,255,255,0.6);
}

.footer h4 {
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 20px;
}

.footer-links {
  list-style: none;
}

/* 页脚产品分类：两列三排 */
.footer-links--2col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 12px;
}

.footer-links li {
  margin-bottom: 12px;
}

.footer-links a {
  font-size: 14px;
  color: rgba(255,255,255,0.6);
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-contact p {
  font-size: 13px;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: rgba(255,255,255,0.4);
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 999;
  box-shadow: var(--shadow);
}

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

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

/* ===== 面包屑 ===== */
.breadcrumb {
  background: linear-gradient(135deg, var(--primary-light) 0%, #ffffff 100%);
  padding: 120px 0 40px;
  text-align: center;
}

.breadcrumb h1 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 8px;
}

.breadcrumb p {
  font-size: 14px;
  color: var(--text-muted);
}

.breadcrumb p a { color: var(--primary); }
.breadcrumb p a:hover { text-decoration: underline; }

/* ===== 响应式 ===== */
@media (max-width: 992px) {
  .about-content,
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 20px;
    gap: 0;
    box-shadow: var(--shadow);
    transform: translateY(-150%);
    transition: var(--transition);
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links li { border-bottom: 1px solid var(--border); }
  .nav-links a { display: block; padding: 14px 0; }
  .nav-links a::after { display: none; }
  .mobile-menu-btn { display: flex; }

  .hero-content h1 { font-size: 32px; }
  .hero-content p { font-size: 16px; }
  .section { padding: 60px 0; }
  .section-header h2 { font-size: 26px; }
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
  .stat-item { padding: 20px 12px; }
  .stat-item .num { font-size: 28px; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .breadcrumb h1 { font-size: 28px; }
}

@media (max-width: 480px) {
  .hero-btns { flex-direction: column; }
  .btn { width: 100%; }
  .features-grid { grid-template-columns: 1fr; }
  .products-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; }
  .footer-contact p { white-space: normal; }
}