/* 全局重置 & 基础样式（SEO友好，语义化） */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft Yahei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
}

body {
  color: #333;
  background-color: #f8f9fa;
  line-height: 1.8;
  font-size: 16px;
}

a {
  text-decoration: none;
  color: #0066cc;
  transition: all 0.3s ease;
}

/* Nofollow链接样式（权重隔离，防止流失） */
a.nofollow {
  rel: "nofollow";
  color: #666;
}

a:hover {
  color: #003399;
}

.container {
  width: 92%;
  max-width: 1280px;
  margin: 0 auto;
}

/* 面包屑导航（SEO友好，提升内链层级） */
.breadcrumb {
  padding: 20px 0;
  font-size: 14px;
  color: #666;
  border-bottom: 1px solid #eee;
}

.breadcrumb a {
  color: #0066cc;
}

.breadcrumb span {
  margin: 0 8px;
  color: #999;
}

/* 主导航栏（粘性布局，提升用户体验） */
.navbar {
  background: linear-gradient(135deg, #0066cc 0%, #003399 100%);
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.15);
  position: sticky;
  top: 0;
  z-index: 999;
}

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

.nav-logo {
  color: #fff;
  font-size: 24px;
  font-weight: 700;
  padding: 20px 0;
}

.nav-logo span {
  color: #ffd700; /* 突出GTV标识 */
}

.nav-menu {
  display: flex;
  list-style: none;
}

.nav-menu li {
  margin-left: 40px;
}

.nav-menu a {
  color: #fff;
  font-size: 16px;
  padding: 20px 0;
  display: block;
  position: relative;
}

.nav-menu a::after {
  content: "";
  position: absolute;
  bottom: 15px;
  left: 0;
  width: 0;
  height: 2px;
  background: #ffd700;
  transition: width 0.3s ease;
}

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

/* Hero区域（500-800字，关键词自然植入） */
.hero {
  background: linear-gradient(rgba(0, 51, 153, 0.85), rgba(0, 102, 204, 0.85)), 
              url("https://picsum.photos/id/1048/1920/600") no-repeat center center;
  background-size: cover;
  padding: 80px 0;
  margin: 20px 0;
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(0, 102, 204, 0.1);
}

.hero-content {
  max-width: 1000px;
  margin: 0 auto;
  color: #fff;
  padding: 0 20px;
}

.hero h1 {
  font-size: 34px;
  margin-bottom: 30px;
  font-weight: 700;
}

.hero p {
  font-size: 18px;
  margin-bottom: 20px;
  line-height: 1.9;
}

/* 独立轮播图样式（SEO友好，alt属性优化） */
.carousel-wrapper {
  width: 100%;
  margin: 40px 0;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

.carousel {
  width: 100%;
  height: 450px;
  position: relative;
  overflow: hidden;
}

.carousel-item {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
  transition: opacity 0.8s ease-in-out;
}

.carousel-item.active {
  opacity: 1;
}

.carousel-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.carousel-caption {
  position: absolute;
  bottom: 30px;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.7);
  color: #fff;
  padding: 25px;
  text-align: center;
  border-radius: 8px;
  margin: 0 30px;
}

.carousel-caption h3 {
  font-size: 24px;
  margin-bottom: 10px;
}

.carousel-caption p {
  font-size: 16px;
  color: #eee;
}

/* 轮播控制按钮 */
.carousel-control {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 56px;
  height: 56px;
  background: rgba(0, 102, 204, 0.8);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  transition: background 0.3s ease;
}

.carousel-control:hover {
  background: rgba(0, 51, 153, 0.9);
}

.carousel-prev {
  left: 20px;
}

.carousel-next {
  right: 20px;
}

/* 核心内容区（左70%+右30%黄金SEO布局） */
.content-wrapper {
  display: flex;
  gap: 30px;
  margin: 40px 0;
}

.main-content {
  width: 70%;
}

.sidebar {
  width: 30%;
}

/* 主内容板块（结构化+配图+专业术语） */
.content-section {
  background: #fff;
  padding: 35px;
  border-radius: 12px;
  margin-bottom: 35px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.content-section h2 {
  color: #003399;
  font-size: 28px;
  margin-bottom: 30px;
  padding-bottom: 15px;
  border-bottom: 2px solid #e6f0ff;
}

.content-section .section-img {
  width: 100%;
  height: 300px;
  border-radius: 8px;
  margin: 25px 0;
  object-fit: cover;
}

.content-section p {
  margin-bottom: 22px;
  line-height: 1.9;
}

/* 专业术语标注样式 */
.term {
  color: #0066cc;
  font-weight: 600;
  border-bottom: 1px dashed #0066cc;
  cursor: help;
}

/* 文章列表（自动化更新，SEO友好） */
.article-list {
  list-style: none;
  margin-top: 25px;
}

.article-item {
  padding: 25px 0;
  border-bottom: 1px dashed #e6f0ff;
}

.article-item:last-child {
  border-bottom: none;
}

.article-title {
  font-size: 22px;
  margin-bottom: 12px;
}

.article-title a {
  color: #003399;
}

.article-title a:hover {
  color: #0066cc;
}

.article-meta {
  font-size: 14px;
  color: #999;
  margin-bottom: 10px;
}

.article-excerpt {
  color: #666;
  line-height: 1.8;
}

.article-excerpt img {
  width: 100px;
  height: 80px;
  float: left;
  margin-right: 15px;
  border-radius: 4px;
  object-fit: cover;
}

/* 侧边栏样式（友情链接+热门推荐+关键词布局） */
.sidebar-widget {
  background: #fff;
  padding: 28px;
  border-radius: 12px;
  margin-bottom: 30px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.sidebar-widget h3 {
  color: #003399;
  font-size: 20px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid #e6f0ff;
}

/* 友情链接列表 */
.friend-link-list {
  list-style: none;
}

.friend-link-list li {
  margin-bottom: 15px;
  padding: 10px 12px;
  background: #e6f0ff;
  border-radius: 8px;
  transition: transform 0.3s ease;
}

.friend-link-list li:hover {
  transform: translateX(6px);
}

.friend-link-list a {
  color: #003399;
  display: block;
}

.friend-link-list .link-desc {
  font-size: 12px;
  color: #666;
  margin-top: 5px;
}

/* 热门推荐列表 */
.hot-recommend-list {
  list-style: none;
}

.hot-recommend-list li {
  margin-bottom: 18px;
  padding-bottom: 18px;
  border-bottom: 1px dashed #e6f0ff;
}

.hot-recommend-list li:last-child {
  border-bottom: none;
}

.hot-title {
  font-size: 18px;
  margin-bottom: 8px;
}

.hot-title a {
  color: #003399;
}

.hot-meta {
  font-size: 14px;
  color: #999;
}

/* 关键词云（SEO布局优化） */
.keyword-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}

.keyword-cloud a {
  background: #e6f0ff;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 14px;
  color: #003399;
}

.keyword-cloud a:hover {
  background: #0066cc;
  color: #fff;
}

/* 页脚样式（横向布局指定模块） */
.footer {
  background: #003399;
  color: #fff;
  padding: 70px 0 30px;
  margin-top: 70px;
  border-radius: 12px 12px 0 0;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  margin-bottom: 40px;
  padding-bottom: 30px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

/* 页脚横向模块（快速链接/联系我们/常见问题/使用条款） */
.footer-column {
  width: 23%;
}

.footer-column h4 {
  font-size: 18px;
  margin-bottom: 25px;
  color: #ffd700;
}

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

.footer-column li {
  margin-bottom: 12px;
}

.footer-column a {
  color: #e0efff;
}

.footer-column a:hover {
  color: #fff;
  text-decoration: underline;
}

/* 页脚版权区 */
.footer-bottom {
  text-align: center;
  padding-top: 30px;
  font-size: 14px;
  color: #e0efff;
}

.footer-bottom-links {
  margin-bottom: 15px;
}

.footer-bottom-links a {
  color: #e0efff;
  margin: 0 15px;
}

.footer-bottom-copyright {
  margin-top: 10px;
}

/* 响应式适配（移动端优化） */
@media (max-width: 768px) {
  .content-wrapper {
    flex-direction: column;
  }
  .main-content, .sidebar {
    width: 100%;
  }
  .footer-top {
    flex-direction: column;
  }
  .footer-column {
    width: 100%;
    margin-bottom: 30px;
  }
  .nav-menu {
    flex-direction: column;
    position: absolute;
    top: 75px;
    left: 0;
    right: 0;
    background: #003399;
    display: none;
    padding: 20px 0;
  }
  .nav-menu li {
    margin: 0;
    padding: 12px 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  .carousel {
    height: 280px;
  }
  .hero {
    padding: 50px 0;
  }
  .hero h1 {
    font-size: 28px;
  }
  .hero p {
    font-size: 16px;
  }
  .content-section {
    padding: 25px;
  }
  .content-section .section-img {
    height: 200px;
  }
}