/* ===== CSS 变量 ===== */
:root {
  --primary: #1a56db;
  --primary-dark: #1a4bc7;
  --primary-light: #e8f0fe;
  --secondary: #0ea5e9;
  --accent: #f59e0b;
  --dark: #1e293b;
  --gray-900: #334155;
  --gray-700: #64748b;
  --gray-500: #94a3b8;
  --gray-300: #cbd5e1;
  --gray-200: #e2e8f0;
  --gray-100: #f1f5f9;
  --gray-50: #f8fafc;
  --white: #ffffff;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --transition: 0.3s ease;
  --max-width: 1200px;
}

/* ===== 全局重置 ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
  color: var(--dark);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
}

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

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

/* ===== 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 transparent;
  transition: all var(--transition);
}

.navbar.scrolled {
  border-bottom-color: var(--gray-200);
  box-shadow: var(--shadow-sm);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--primary);
}

.logo i {
  font-size: 1.8rem;
  color: var(--primary);
}

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

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--gray-700);
  position: relative;
  padding: 4px 0;
}

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

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

.nav-links a:hover::after,
.nav-links a.active::after {
  transform: scaleX(1);
}

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

.hamburger span {
  display: block;
  width: 26px;
  height: 2.5px;
  background: var(--dark);
  border-radius: 2px;
  transition: all var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.hamburger.active span:nth-child(2) {
  opacity: 0;
}
.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero 区域 ===== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #1e40af 50%, #0c1d5e 100%);
  color: var(--white);
  padding: 160px 0 120px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.05) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(255,255,255,0.03) 0%, transparent 40%);
  pointer-events: none;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 20px;
  position: relative;
  line-height: 1.3;
}

.hero p {
  font-size: 1.2rem;
  opacity: 0.9;
  max-width: 680px;
  margin: 0 auto 40px;
  position: relative;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  font-family: inherit;
}

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

.btn-primary:hover {
  background: var(--gray-100);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255,255,255,0.5);
}

.btn-outline:hover {
  background: rgba(255,255,255,0.1);
  border-color: var(--white);
  transform: translateY(-2px);
}

/* ===== Section 通用 ===== */
.section {
  padding: 100px 0;
}

.section-gray {
  background: var(--gray-50);
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px;
}

.section-header p {
  color: var(--gray-700);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

.section-header .divider {
  width: 60px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
  margin: 16px auto 0;
}

/* ===== 关于区域预览 ===== */
.about-preview {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-preview .about-img {
  background: linear-gradient(135deg, var(--primary-light), #dbeafe);
  border-radius: var(--radius-lg);
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-preview .about-img i {
  font-size: 8rem;
  color: var(--primary);
  opacity: 0.6;
}

.about-text h3 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--dark);
}

.about-text p {
  color: var(--gray-700);
  margin-bottom: 24px;
  line-height: 1.8;
}

.about-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 24px;
}

.about-feature {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--gray-50);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
}

.about-feature i {
  color: var(--primary);
  font-size: 1.2rem;
}

/* ===== 服务卡片 ===== */
.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-sm);
  border: 1px solid var(--gray-200);
  transition: all var(--transition);
  text-align: center;
}

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

.service-card .icon-circle {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 1.8rem;
  transition: all var(--transition);
}

.service-card:hover .icon-circle {
  background: var(--primary);
  color: var(--white);
}

.service-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--dark);
}

.service-card p {
  color: var(--gray-700);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ===== 优势区域 ===== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.advantage-item {
  text-align: center;
  padding: 32px 20px;
}

.advantage-item .adv-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 8px;
}

.advantage-item .adv-label {
  color: var(--gray-700);
  font-size: 0.95rem;
}

/* ===== CTA 区域 ===== */
.cta-section {
  background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%);
  color: var(--white);
  text-align: center;
  padding: 80px 0;
}

.cta-section h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 14px;
}

.cta-section p {
  opacity: 0.9;
  margin-bottom: 32px;
  font-size: 1.05rem;
}

/* ===== Footer ===== */
.footer {
  background: var(--dark);
  color: #cbd5e1;
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  padding-bottom: 40px;
}

.footer-col h4 {
  color: var(--white);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.footer-col p {
  line-height: 1.8;
  font-size: 0.9rem;
}

.footer-col ul li {
  margin-bottom: 10px;
  font-size: 0.9rem;
}

.footer-col ul li a:hover {
  color: var(--white);
}

.footer-col ul li i {
  margin-right: 8px;
  color: var(--secondary);
  width: 16px;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 24px 0;
  text-align: center;
}

.beian-info {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.85rem;
  color: #94a3b8;
  margin-bottom: 8px;
}

.beian-info a {
  color: #94a3b8;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: color var(--transition);
}

.beian-info a:hover {
  color: var(--white);
}

.beian-info img {
  width: 14px;
  height: 14px;
  opacity: 0.7;
}

.beian-divider {
  color: rgba(255,255,255,0.2);
}

.copyright {
  font-size: 0.8rem;
  color: #64748b;
  margin-top: 4px;
}

/* ===== 页面标题 ===== */
.page-title {
  background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%);
  color: var(--white);
  padding: 130px 0 60px;
  text-align: center;
}

.page-title h1 {
  font-size: 2.4rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.page-title p {
  opacity: 0.8;
  font-size: 1rem;
}

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

.about-content .about-img-large {
  background: linear-gradient(135deg, var(--primary-light), #dbeafe);
  border-radius: var(--radius-lg);
  height: 420px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-content .about-img-large i {
  font-size: 9rem;
  color: var(--primary);
  opacity: 0.5;
}

/* 时间线 */
.timeline {
  position: relative;
  padding-left: 28px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--gray-300);
}

.timeline-item {
  position: relative;
  margin-bottom: 36px;
  padding-left: 28px;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -21px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--primary);
  border: 3px solid var(--white);
  box-shadow: 0 0 0 3px var(--primary);
}

.timeline-item h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.timeline-item .year {
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 6px;
}

.timeline-item p {
  color: var(--gray-700);
  font-size: 0.95rem;
}

/* ===== 服务详情页面 ===== */
.service-detail-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-detail-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 40px 28px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  transition: all var(--transition);
}

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

.service-detail-card .sd-icon {
  font-size: 2.5rem;
  color: var(--primary);
  margin-bottom: 20px;
}

.service-detail-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.service-detail-card p {
  color: var(--gray-700);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.service-detail-card ul {
  padding: 0;
}

.service-detail-card ul li {
  padding: 5px 0;
  color: var(--gray-700);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.service-detail-card ul li i {
  color: var(--primary);
  font-size: 0.85rem;
}

/* ===== 案例页面 ===== */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.case-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  transition: all var(--transition);
}

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

.case-img {
  height: 200px;
  background: linear-gradient(135deg, var(--primary-light), #dbeafe);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: var(--primary);
  opacity: 0.7;
}

.case-body {
  padding: 24px;
}

.case-body .tag {
  display: inline-block;
  padding: 4px 12px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.case-body h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.case-body p {
  color: var(--gray-700);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ===== 联系页面 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 40px;
}

.contact-info-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-info-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-info-card .ci-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.contact-info-card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.contact-info-card p {
  color: var(--gray-700);
  font-size: 0.9rem;
}

.contact-form-wrap {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
}

.contact-form-wrap h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 24px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--dark);
}

.form-group input,
.form-group select,
.form-group textarea {
  padding: 12px 16px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

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

.btn-submit {
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

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

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

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

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .services-grid,
  .service-detail-cards,
  .cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .about-preview,
  .about-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-preview .about-img,
  .about-content .about-img-large {
    height: 300px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px;
    gap: 20px;
    border-bottom: 1px solid var(--gray-200);
    box-shadow: var(--shadow-md);
    transform: translateY(-120%);
    transition: transform var(--transition);
    opacity: 0;
    pointer-events: none;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .hamburger {
    display: flex;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .section {
    padding: 60px 0;
  }

  .section-header h2 {
    font-size: 1.7rem;
  }

  .services-grid,
  .service-detail-cards,
  .cases-grid {
    grid-template-columns: 1fr;
  }

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

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

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

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 120px 0 80px;
  }

  .hero h1 {
    font-size: 1.6rem;
  }

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

  .hero-btns {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }
}