/* 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;
}

/* 封面区域样式 */
.cover-container {
  position: relative;
  height: 500px;
  overflow: hidden;
  margin-bottom: 40px;
}

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

.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;
}

/* 新闻内容区域样式 */
.news-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
  background: #ffffff;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  border-radius: 8px;
  margin-top: -40px;
  position: relative;
  z-index: 1;
}

/* 视频区域样式 */
.video-section {
  margin: 40px 0;
  padding: 30px;
  background: #f8f9fa;
  border-radius: 8px;
  border-left: 4px solid #4CAF50;
}

.video-section h4 {
  color: #2c3e50;
  margin-bottom: 20px;
  font-size: 1.5em;
  font-weight: 600;
}

.video-container {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  background: #000;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.video-container video {
  width: 100%;
  height: auto;
  display: block;
}

.video-caption {
  text-align: center;
  margin-top: 15px;
  color: #666;
  font-size: 0.95em;
  font-style: italic;
}

.news-main {
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  padding: 60px;
}

/* 标题样式 */
.news-main h2 {
  color: #1a1a1a;
  font-size: 2.2em;
  font-weight: 700;
  margin-bottom: 10px;
  line-height: 1.3;
}

.news-main h3 {
  color: #666;
  font-size: 1.3em;
  font-weight: 500;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px solid #e0e0e0;
}

/* 图片容器样式 */
.image-container {
  margin: 25px 0;
  text-align: center;
}

/* 文章图片样式 */
.article-image {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  border: 1px solid #e0e0e0;
}

/* 图片说明文字样式 */
.image-caption {
  margin-top: 10px;
  font-size: 0.95em;
  color: #666;
  font-style: italic;
  text-align: center;
}

/* 段落样式 */
.news-main p {
  margin-bottom: 25px;
  font-size: 1.05em;
  line-height: 1.8;
  text-align: justify;
  color: #444;
}

/* 章节样式 */
.section {
  margin: 40px 0;
  padding: 30px;
  background: #f9fbf8;
  border-radius: 8px;
  border-left: 4px solid #4CAF50;
}

.section h4 {
  color: #4CAF50;
  font-size: 1.5em;
  font-weight: 600;
  margin-bottom: 20px;
}

/* 解决方案和战略意义项目样式 */
.solution-item,
.significance-item {
  margin: 25px 0;
  padding: 20px;
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.solution-item h5,
.significance-item h5 {
  color: #333;
  font-size: 1.2em;
  font-weight: 600;
  margin-bottom: 15px;
}

.solution-item p,
.significance-item p {
  margin-bottom: 0;
  font-size: 1em;
}

/* 引用样式 */
.news-main p:contains('"') {
  font-style: italic;
  color: #555;
}

/* 页脚样式 */
.footer {
  background: #1a1a1a;
  color: white;
  padding: 60px 0 30px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  padding: 0 20px;
}

.footer-left {
  flex: 0 0 40%;
}

.footer-logo h3 {
  font-size: 1.5em;
  margin-bottom: 20px;
  color: #4CAF50;
}

.footer-logo p {
  color: #ccc;
  line-height: 1.8;
  margin-bottom: 0;
}

.footer-nav {
  flex: 0 0 55%;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.footer-link-group h4 {
  color: #4CAF50;
  margin-bottom: 20px;
  font-size: 1.1em;
}

.footer-link-group ul {
  list-style: none;
}

.footer-link-group li {
  margin-bottom: 10px;
}

.footer-link-group a {
  color: #ccc;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-link-group a:hover {
  color: #4CAF50;
}

.footer .divider {
  width: 100%;
  height: 1px;
  background: #333;
  margin: 40px 0;
}

.contact-info {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
  margin-bottom: 30px;
}

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

.contact-column p {
  margin-bottom: 8px;
  color: #ccc;
}

.contact-image img {
  max-width: 120px;
}

.copyright {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #333;
  color: #999;
  font-size: 0.9em;
}

.copyright a {
  color: #4CAF50;
  text-decoration: none;
}

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

.security-beian-image {
  height: 16px;
  vertical-align: middle;
  margin-right: 5px;
}

/* 响应式设计 */
@media (max-width: 1200px) {
  .news-main {
    padding: 40px;
  }
  
  .banner-title {
    font-size: 2.2em;
  }
  
  .footer-links {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 992px) {
  .main-menu {
    gap: 20px;
  }
  
  .dropdown-content {
    min-width: 700px;
    gap: 20px;
    padding: 20px;
  }
  
  .banner-title {
    font-size: 1.8em;
  }
  
  .news-main h2 {
    font-size: 1.8em;
  }
  
  .footer-container {
    flex-direction: column;
    gap: 40px;
  }
  
  .footer-left,
  .footer-nav {
    flex: 0 0 100%;
  }
}

@media (max-width: 768px) {
  .cover-container {
    height: 300px;
  }
  
  .banner-title {
    font-size: 1.5em;
    left: 5%;
    max-width: 90%;
  }
  
  .news-main {
    padding: 25px;
  }
  
  .news-main h2 {
    font-size: 1.6em;
  }
  
  .news-main h3 {
    font-size: 1.1em;
  }
  
  /* 响应式图片样式 */
  .image-container {
    margin: 20px 0;
  }
  
  .article-image {
    border-radius: 6px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  }
  
  .image-caption {
    font-size: 0.9em;
    padding: 0 10px;
  }
  
  .section {
    padding: 20px;
  }
  
  .section h4 {
    font-size: 1.3em;
  }
  
  .video-section {
    padding: 20px 15px;
    margin: 30px 0;
  }
  
  .video-section h4 {
    font-size: 1.3em;
    text-align: center;
  }
  
  .video-container {
    max-width: 100%;
  }
  
  .video-caption {
    font-size: 0.9em;
    padding: 0 10px;
  }
  
  .contact-info {
    flex-direction: column;
    gap: 30px;
    text-align: center;
  }
}