/* 基本样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary-color: #1F4D7A;
  --secondary-color: #3D7AB6;
  --accent-color: #F2A03D;
  --text-color: #333333;
  --light-text: #ffffff;
  --bg-light: #f9f9f9;
  --bg-dark: #0A2847;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --border-radius: 4px;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

body {
  font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--bg-light);
}

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

a:hover {
  color: var(--secondary-color);
}

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

/* 容器和布局 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.row {
  display: flex;
  flex-wrap: wrap;
  margin: 0 -15px;
}

.col {
  padding: 0 15px;
  flex: 1;
}

/* 响应式栅格系统 */
.col-1 { flex: 0 0 8.33%; }
.col-2 { flex: 0 0 16.66%; }
.col-3 { flex: 0 0 25%; }
.col-4 { flex: 0 0 33.33%; }
.col-5 { flex: 0 0 41.66%; }
.col-6 { flex: 0 0 50%; }
.col-7 { flex: 0 0 58.33%; }
.col-8 { flex: 0 0 66.66%; }
.col-9 { flex: 0 0 75%; }
.col-10 { flex: 0 0 83.33%; }
.col-11 { flex: 0 0 91.66%; }
.col-12 { flex: 0 0 100%; }

/* 导航栏 */
.header {
  background-color: var(--bg-dark);
  color: var(--light-text);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo img {
  height: 40px;
  width: auto;
}

.logo h1 {
  font-size: 1.5rem;
  font-weight: 600;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
}

.nav-links li a {
  color: var(--light-text);
  font-weight: 500;
  position: relative;
  padding: var(--spacing-sm);
}

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

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

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

.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--light-text);
  font-size: 1.5rem;
  cursor: pointer;
}

/* 英雄区域 */
.hero {
  background: linear-gradient(135deg, var(--primary-color), var(--bg-dark));
  color: var(--light-text);
  padding: var(--spacing-xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
  animation: rotate 30s linear infinite;
}

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

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

.hero h2 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
  font-weight: 700;
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: var(--spacing-lg);
  opacity: 0.9;
}

.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  border-radius: var(--border-radius);
  background-color: var(--accent-color);
  color: var(--light-text);
  font-weight: 600;
  text-align: center;
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.btn:hover {
  background-color: #e08b25;
  transform: translateY(-3px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

/* 特色服务 */
.services {
  padding: var(--spacing-xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title h2 {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: var(--spacing-sm);
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  position: absolute;
  width: 60%;
  height: 3px;
  background-color: var(--accent-color);
  bottom: -10px;
  left: 20%;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.service-card {
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  padding: var(--spacing-lg);
  transition: var(--transition);
  text-align: center;
  height: 100%;
}

.service-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.service-icon {
  margin-bottom: var(--spacing-md);
  color: var(--primary-color);
  font-size: 3rem;
}

.service-card h3 {
  margin-bottom: var(--spacing-md);
  color: var(--primary-color);
}

/* 关于我们 */
.about {
  padding: var(--spacing-xl) 0;
  background-color: #f5f8fb;
}

.about-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.about-text {
  flex: 1;
}

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

.about-stats {
  display: flex;
  margin-top: var(--spacing-lg);
  text-align: center;
}

.stat {
  flex: 1;
  padding: var(--spacing-md);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: var(--spacing-sm);
}

/* 案例展示 */
.case-studies {
  padding: var(--spacing-xl) 0;
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-lg);
}

.case-card {
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: var(--transition);
}

.case-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.case-image {
  height: 200px;
  background-color: #e1e1e1;
  position: relative;
  overflow: hidden;
}

.case-content {
  padding: var(--spacing-lg);
}

.case-content h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--primary-color);
}

.case-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: var(--spacing-sm);
}

.tag {
  background-color: rgba(31, 77, 122, 0.1);
  color: var(--primary-color);
  padding: 0.2rem 0.6rem;
  border-radius: 20px;
  font-size: 0.8rem;
}

/* 联系我们 */
.contact {
  padding: var(--spacing-xl) 0;
  background-color: #f5f8fb;
}

.contact-content {
  display: flex;
  gap: var(--spacing-xl);
}

.contact-info {
  flex: 1;
}

.contact-info ul {
  list-style: none;
  margin-top: var(--spacing-lg);
}

.contact-info li {
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.contact-info .icon {
  width: 40px;
  height: 40px;
  background-color: var(--primary-color);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
}

.contact-form {
  flex: 1;
  background-color: white;
  padding: var(--spacing-lg);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
}

.form-control {
  width: 100%;
  padding: 0.8rem;
  border: 1px solid #ddd;
  border-radius: var(--border-radius);
  font-family: inherit;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
}

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

/* 页脚 */
.footer {
  background-color: var(--bg-dark);
  color: var(--light-text);
  padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

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

.footer-col h3 {
  margin-bottom: var(--spacing-md);
  color: var(--light-text);
  position: relative;
}

.footer-col h3::after {
  content: '';
  position: absolute;
  width: 40px;
  height: 2px;
  background-color: var(--accent-color);
  bottom: -10px;
  left: 0;
}

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

.footer-col ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-col ul li a {
  color: rgba(255, 255, 255, 0.7);
}

.footer-col ul li a:hover {
  color: var(--light-text);
  padding-left: 5px;
}

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

.social-links {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  transition: var(--transition);
}

.social-links a:hover {
  background-color: var(--accent-color);
  transform: translateY(-3px);
}

/* 响应式设计 */
@media (max-width: 992px) {
  .hero h2 {
    font-size: 2rem;
  }
  
  .about-content {
    flex-direction: column;
  }
  
  .about-image {
    order: -1;
    margin-bottom: var(--spacing-lg);
  }
  
  .contact-content {
    flex-direction: column;
  }
}

@media (max-width: 768px) {
  .mobile-nav-toggle {
    display: block;
  }
  
  .nav-links {
    position: fixed;
    top: 70px;
    right: -100%;
    flex-direction: column;
    background-color: var(--bg-dark);
    width: 80%;
    height: 100vh;
    padding: var(--spacing-lg);
    transition: var(--transition);
    box-shadow: -5px 0 15px rgba(0, 0, 0, 0.2);
  }
  
  .nav-links.active {
    right: 0;
  }
  
  .hero h2 {
    font-size: 1.8rem;
  }
  
  .services-grid {
    grid-template-columns: 1fr;
  }
  
  .case-grid {
    grid-template-columns: 1fr;
  }
  
  .col-1, .col-2, .col-3, .col-4, .col-5, .col-6, 
  .col-7, .col-8, .col-9, .col-10, .col-11, .col-12 {
    flex: 0 0 100%;
  }
}

@media (max-width: 576px) {
  :root {
    --spacing-xl: 2rem;
  }
  
  .section-title h2 {
    font-size: 1.5rem;
  }
  
  .hero h2 {
    font-size: 1.5rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .service-card,
  .case-card,
  .contact-form {
    padding: var(--spacing-md);
  }
}

/* 动画效果 */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* 返回顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background-color: var(--primary-color);
  color: var(--light-text);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: var(--transition);
  visibility: hidden;
  z-index: 99;
  cursor: pointer;
}

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

.back-to-top:hover {
  background-color: var(--secondary-color);
}

/* 面包屑导航 */
.breadcrumb {
  display: flex;
  list-style: none;
  background-color: #f1f1f1;
  padding: 10px;
  border-radius: var(--border-radius);
  margin-bottom: var(--spacing-lg);
}

.breadcrumb li {
  display: flex;
  align-items: center;
}

.breadcrumb li + li::before {
  content: "/";
  padding: 0 10px;
  color: #6c757d;
}

.breadcrumb a {
  color: var(--primary-color);
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb .active {
  color: #6c757d;
}