/* 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}

/* 导航栏样式 */
nav {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 15px 5%;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

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

.main-menu a {
  text-decoration: none;
  color: #333;
  font-weight: 500;
  transition: color 0.3s ease;
}

.main-menu a:hover {
  color: #4CAF50;
}

.dropdown {
  position: relative;
}

.dropdown-content {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: white;
  border-radius: 8px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
  padding: 30px;
  display: none;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  min-width: 900px;
}

.dropdown:hover .dropdown-content {
  display: grid;
}

.submenu h4 {
  color: #4CAF50;
  margin-bottom: 15px;
  font-size: 1.1em;
}

.submenu ul {
  list-style: none;
}

.submenu li {
  margin-bottom: 8px;
}

.submenu a {
  color: #666;
  font-size: 0.95em;
}

.submenu a:hover {
  color: #4CAF50;
}

.divider {
  width: 1px;
  background: #e0e0e0;
}

.banner-title {
  position: absolute;
  top: 50%;
  left: 10%;
  transform: translateY(-50%);
  color: white;
  font-size: 2.8em;
  font-weight: 700;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.7);
  z-index: 2;
  max-width: 70%;
  line-height: 1.3;
}

/* 页面内容容器 */
.page-content {
  margin-top: 80px;
  min-height: calc(100vh - 120px);
}

/* 封面容器样式 */
.cover-container {
  position: relative;
  width: 100%;
  height: 400px;
  overflow: hidden;
}

.cover-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(0.7);
}

/* 新闻内容区域样式 */
.news-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

.news-date {
  color: #666;
  font-size: 16px;
  margin-bottom: 30px;
  text-align: center;
  padding-bottom: 20px;
  border-bottom: 1px solid #e0e0e0;
}

.news-body {
  color: #333;
  line-height: 1.8;
  font-size: 18px;
}

.news-body p {
  margin-bottom: 25px;
  text-align: justify;
}

.news-body h2 {
  color: #1E88E5;
  font-size: 28px;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 25px;
  padding-bottom: 15px;
  border-bottom: 3px solid #e3f2fd;
}

/* 图片容器样式 */
.image-container {
  margin: 40px 0;
  text-align: center;
}

.news-image {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease;
}

.news-image:hover {
  transform: scale(1.02);
}

.image-caption {
  margin-top: 15px;
  color: #666;
  font-size: 16px;
  font-style: italic;
  text-align: center;
}

/* 数据高亮区域样式 */
.data-highlight {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  padding: 30px;
  border-radius: 12px;
  margin: 40px 0;
}

.data-item {
  text-align: center;
  flex: 1;
  min-width: 150px;
  margin: 15px;
}

.data-number {
  font-size: 36px;
  font-weight: bold;
  color: #1E88E5;
  margin-bottom: 10px;
  font-family: 'Arial', sans-serif;
}

.data-label {
  font-size: 18px;
  color: #555;
}

/* 回到顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: #1E88E5;
  color: white;
  border: none;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
  opacity: 0;
  transition: opacity 0.3s, background-color 0.3s;
  z-index: 1000;
}

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

.back-to-top:hover {
  background: #1976D2;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .banner-title {
    font-size: 2em;
    left: 5%;
    max-width: 90%;
  }
  
  .cover-container {
    height: 300px;
  }
  
  .news-content {
    padding: 20px 15px;
  }
  
  .news-body {
    font-size: 16px;
  }
  
  .news-body h2 {
    font-size: 24px;
  }
  
  .data-highlight {
    flex-direction: column;
    padding: 20px;
  }
  
  .data-item {
    margin: 10px 0;
  }
  
  .data-number {
    font-size: 28px;
  }
}