/* ================================
   全局样式与变量
   ================================ */
:root {
  --primary-color: #2563eb;
  --secondary-color: #1e40af;
  --accent-color: #3b82f6;
  --text-dark: #1f2937;
  --text-light: #6b7280;
  --bg-light: #f9fafb;
  --bg-white: #ffffff;
  --border-color: #e5e7eb;
  --success-color: #10b981;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', '微软雅黑', sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--bg-white);
  overflow-x: hidden;
}

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

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

button {
  cursor: pointer;
  border: none;
  outline: none;
  transition: var(--transition);
}

/* ================================
   导航栏样式
   ================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: var(--transition);
}

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

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo span {
  font-size: 16px;
  color: var(--text-light);
  font-weight: 400;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 40px;
  align-items: center;
}

.nav-menu a {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-dark);
  position: relative;
  padding: 5px 0;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: width 0.3s ease;
}

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

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

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  padding: 5px;
}

.mobile-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--text-dark);
  border-radius: 3px;
  transition: var(--transition);
}

/* ================================
   Hero区域样式
   ================================ */
.hero {
  margin-top: 70px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 100px 20px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.1)" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,112C672,96,768,96,864,112C960,128,1056,160,1152,160C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
  background-size: cover;
  opacity: 0.3;
}

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

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 20px;
  animation: fadeInUp 0.8s ease;
}

.hero p {
  font-size: 20px;
  margin-bottom: 30px;
  opacity: 0.95;
  animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  animation: fadeInUp 0.8s ease 0.4s backwards;
}

.btn {
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  border-radius: 8px;
  transition: var(--transition);
  display: inline-block;
}

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

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

.btn-secondary {
  background: transparent;
  color: white;
  border: 2px solid white;
}

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

/* ================================
   容器与布局
   ================================ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 80px 0;
}

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

.section-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 15px;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: var(--primary-color);
  border-radius: 2px;
}

.section-subtitle {
  font-size: 18px;
  color: var(--text-light);
  margin-top: 20px;
}

/* ================================
   服务卡片样式
   ================================ */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 30px;
}

.service-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 40px 30px;
  transition: var(--transition);
  cursor: pointer;
}

.service-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-color);
}

.service-icon {
  font-size: 48px;
  margin-bottom: 20px;
  display: block;
}

.service-card h3 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 15px;
  color: var(--text-dark);
}

.service-card p {
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 20px;
}

.service-features {
  list-style: none;
}

.service-features li {
  padding: 8px 0;
  color: var(--text-light);
  font-size: 14px;
  position: relative;
  padding-left: 20px;
}

.service-features li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: 700;
}

/* ================================
   案例展示样式
   ================================ */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 30px;
}

.case-card {
  background: var(--bg-white);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

.case-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.case-image {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 80px;
}

.case-content {
  padding: 25px;
}

.case-category {
  display: inline-block;
  padding: 4px 12px;
  background: var(--bg-light);
  color: var(--primary-color);
  font-size: 12px;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 15px;
}

.case-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-dark);
}

.case-card p {
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 15px;
}

.case-achievement {
  background: var(--bg-light);
  padding: 12px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--success-color);
  font-weight: 500;
  margin-bottom: 15px;
}

.case-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.case-tag {
  padding: 4px 10px;
  background: var(--primary-color);
  color: white;
  font-size: 12px;
  border-radius: 4px;
}

/* ================================
   新闻列表样式
   ================================ */
.news-list {
  display: grid;
  gap: 25px;
}

.news-item {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 25px;
  transition: var(--transition);
  display: flex;
  gap: 25px;
  align-items: flex-start;
}

.news-item:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.news-date {
  min-width: 80px;
  text-align: center;
}

.news-day {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
}

.news-month {
  font-size: 14px;
  color: var(--text-light);
  margin-top: 5px;
}

.news-content {
  flex: 1;
}

.news-category {
  display: inline-block;
  padding: 3px 10px;
  background: var(--accent-color);
  color: white;
  font-size: 12px;
  border-radius: 4px;
  margin-bottom: 10px;
}

.news-item h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-dark);
}

.news-item p {
  color: var(--text-light);
  line-height: 1.8;
}

/* ================================
   关于我们页面样式
   ================================ */
.about-intro {
  background: var(--bg-light);
  padding: 60px 40px;
  border-radius: 12px;
  margin-bottom: 60px;
}

.company-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.info-item {
  text-align: center;
  padding: 30px;
  background: var(--bg-white);
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
}

.info-item-icon {
  font-size: 40px;
  margin-bottom: 15px;
}

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

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

.values-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 25px;
  margin-top: 40px;
}

.value-item {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: 40px 25px;
  text-align: center;
  border-radius: 12px;
  font-size: 20px;
  font-weight: 600;
  transition: var(--transition);
}

.value-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

/* ================================
   联系页面样式
   ================================ */
.contact-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.contact-info {
  display: grid;
  gap: 25px;
}

.contact-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.contact-icon {
  font-size: 32px;
  color: var(--primary-color);
}

.contact-details h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.contact-details p {
  color: var(--text-light);
  line-height: 1.6;
}

.contact-form {
  background: var(--bg-light);
  padding: 40px;
  border-radius: 12px;
}

.form-group {
  margin-bottom: 25px;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-dark);
}

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

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

.submit-btn {
  width: 100%;
  padding: 14px;
  background: var(--primary-color);
  color: white;
  font-size: 16px;
  font-weight: 600;
  border-radius: 8px;
}

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

/* ================================
   页脚样式
   ================================ */
.footer {
  background: var(--text-dark);
  color: white;
  padding: 60px 0 0;
  margin-top: 80px;
}

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

.footer-section h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 20px;
}

.footer-section p {
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.8;
  margin-bottom: 15px;
}

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

.footer-links li {
  margin-bottom: 12px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  transition: var(--transition);
  display: inline-block;
  max-width: 100%;
}

.footer-links a:hover {
  color: white;
  padding-left: 5px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 25px 0;
  text-align: center;
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.9);
  text-decoration: underline;
}

/* ================================
   动画效果
   ================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeInUp 0.6s ease;
}

/* ================================
   响应式设计 - 平板
   ================================ */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 36px;
  }

  .hero p {
    font-size: 18px;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 28px;
  }

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

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

  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }

  .news-item {
    flex-direction: column;
  }

  .news-date {
    min-width: auto;
    text-align: left;
  }
}

/* ================================
   响应式设计 - 手机
   ================================ */
@media (max-width: 480px) {
  .nav-menu {
    position: fixed;
    top: 70px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 70px);
    background: var(--bg-white);
    flex-direction: column;
    gap: 0;
    padding: 20px;
    box-shadow: var(--shadow-lg);
    transition: left 0.3s ease;
  }

  .nav-menu.active {
    left: 0;
  }

  .nav-menu li {
    width: 100%;
    border-bottom: 1px solid var(--border-color);
  }

  .nav-menu a {
    display: block;
    padding: 15px 0;
  }

  .mobile-toggle {
    display: flex;
  }

  .mobile-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
  }

  .mobile-toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .mobile-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
  }

  .hero {
    padding: 60px 20px;
  }

  .hero h1 {
    font-size: 28px;
  }

  .hero p {
    font-size: 16px;
  }

  .section-title {
    font-size: 24px;
  }

  .section-subtitle {
    font-size: 16px;
  }

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

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

  .service-card,
  .case-card {
    margin: 0;
  }
}

/* ================================
   工具类
   ================================ */
.text-center {
  text-align: center;
}

.mt-20 {
  margin-top: 20px;
}

.mb-20 {
  margin-bottom: 20px;
}

.hidden {
  display: none;
}