html, body {
  padding: 0;
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Noto Sans SC", sans-serif;
  color: #222;
  background: #f5f5f6;
  line-height: 1.7;
}

* { box-sizing: border-box; }

/* 配色方案 - 信任蓝/成功绿/警示红 */
:root {
  --color-primary: #1a73e8;
  --color-primary-light: #4285f4;
  --color-success: #34a853;
  --color-warning: #ea4335;
  --color-gold: #c9a227;
  --color-text: #202124;
  --color-text-secondary: #5f6368;
  --color-border: #dadce0;
  --color-bg: #f8f9fa;
  --spacing-unit: 8px;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}

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

.skip-link {
  position: absolute;
  left: -999px;
  top: 10px;
  background: #111;
  color: #fff;
  padding: 8px 10px;
  border-radius: 10px;
  z-index: 999;
}

.skip-link:focus {
  left: 12px;
}

.sr-only {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 calc(var(--spacing-unit) * 2);
}

/* 固定导航 - 页头固定、滚动变白 */
.site-header {
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
  transition: background 0.3s, box-shadow 0.3s;
}

.site-header.scrolled {
  background: #ffffff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.site-header .bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: calc(var(--spacing-unit) * 1.5);
  height: 56px;
}

/* LOGO金色化 */
.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-gold);
  white-space: nowrap;
  letter-spacing: -0.5px;
}

.logo a {
  color: var(--color-gold);
}

.nav {
  display: flex;
  align-items: center;
  gap: calc(var(--spacing-unit) * 0.5);
  overflow: auto;
  -webkit-overflow-scrolling: touch;
}

.nav a {
  display: inline-block;
  padding: calc(var(--spacing-unit) * 0.75) calc(var(--spacing-unit) * 1.25);
  border-radius: 20px;
  color: var(--color-text-secondary);
  white-space: nowrap;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s;
}

.nav a:hover {
  color: var(--color-primary);
  background: rgba(26, 115, 232, 0.08);
}

.nav a.active {
  background: rgba(26, 115, 232, 0.12);
  color: var(--color-primary);
}

.main-wrap {
  margin-top: calc(var(--spacing-unit) * 2);
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: calc(var(--spacing-unit) * 2);
}

/* 卡片样式 - 细边框、hover微上浮 */
.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.main-col { min-width: 0; }
.side-col { min-width: 0; }

.card .hd {
  padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
  border-bottom: 1px solid #f0f0f0;
  font-weight: 700;
}

.card .bd {
  padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
}

.article-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.article-list li {
  padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
  border-bottom: 1px solid #f5f5f5;
  transition: background 0.2s;
}

.article-list li:hover {
  background: #fafbfc;
}

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

/* 标题加大加粗 */
.article-title {
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 calc(var(--spacing-unit) * 0.75) 0;
  line-height: 1.4;
  color: var(--color-text);
}

.page-title {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

.meta {
  font-size: 13px;
  color: var(--color-text-secondary);
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--spacing-unit) * 1.25);
}

/* 文章内容优化 - 最大宽度720px、行高1.7 */
.article-content {
  line-height: 1.75;
  font-size: 16px;
  word-break: break-word;
  max-width: 1100px;
}

.article-content p {
  margin: 0 0 calc(var(--spacing-unit) * 1.5) 0;
  color: var(--color-text);
}

/* 标题层次 */
.article-content h2,
.article-content h3 {
  line-height: 1.35;
  margin: calc(var(--spacing-unit) * 3) 0 calc(var(--spacing-unit) * 1.5);
  color: var(--color-text);
  font-weight: 700;
}

.article-content h2 { 
  font-size: 22px; 
  border-bottom: 2px solid var(--color-primary);
  padding-bottom: calc(var(--spacing-unit) * 0.75);
}

.article-content h3 { 
  font-size: 18px; 
  color: var(--color-primary);
}

.article-content blockquote {
  margin: calc(var(--spacing-unit) * 2) 0;
  padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
  border-left: 4px solid var(--color-primary);
  background: #f5f9ff;
  color: #334;
  border-radius: 0 8px 8px 0;
}

.article-content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.9em;
  background: #f1f3f5;
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--color-warning);
}

.article-content pre {
  overflow: auto;
  background: #1a1a2e;
  color: #e7e9ee;
  padding: calc(var(--spacing-unit) * 1.5);
  border-radius: 10px;
  margin: calc(var(--spacing-unit) * 2) 0;
}

.article-content pre code {
  background: transparent;
  padding: 0;
  border-radius: 0;
  color: inherit;
}

/* 图片懒加载优化 */
.article-content img {
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.article-content video {
  max-width: 100%;
  height: auto;
  border-radius: 10px;
}

.pagination {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--spacing-unit) * 1);
  padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
  border-top: 1px solid #f0f0f0;
}

.pagination a, .pagination span {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: #fff;
  color: var(--color-text);
  font-size: 14px;
  transition: all 0.2s;
}

.pagination a:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.pagination span.current {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.ad {
  border: 1px dashed #d6d6d6;
  border-radius: 10px;
  padding: 10px;
  background: #fafafa;
  margin-bottom: calc(var(--spacing-unit) * 1.5);
}

.ad img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: 10px;
}

.home-banner .ad {
  margin-top: calc(var(--spacing-unit) * 1.5);
  padding: 0;
  border: 0;
  background: transparent;
  max-height: 80px;
  overflow: hidden;
}

.home-banner .ad img {
  width: 100%;
  height: 80px;
  object-fit: cover;
}

.title-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.title-list li {
  padding: calc(var(--spacing-unit) * 1) 0;
  border-bottom: 1px solid #f3f3f3;
  font-size: 14px;
}
.title-list li:last-child { border-bottom: none; }

.geo-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--spacing-unit) * 1.25);
}

.geo-item {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: calc(var(--spacing-unit) * 1.25);
  align-items: center;
  padding: calc(var(--spacing-unit) * 1.25);
  border: 1px solid #f0f0f0;
  border-radius: 12px;
  background: #fff;
  color: inherit;
  transition: all 0.2s;
}

.geo-item:hover {
  text-decoration: none;
  border-color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(26, 115, 232, 0.1);
}

.geo-item img {
  width: 120px;
  height: 68px;
  object-fit: cover;
  border-radius: 8px;
}

.geo-item__bd { min-width: 0; }

.geo-item__title {
  font-weight: 700;
  font-size: 14px;
  line-height: 1.35;
  margin-bottom: 6px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* 分类标签 - 圆角胶囊样式 */
.tag-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: calc(var(--spacing-unit) * 1);
}

.tag-grid .tag {
  display: inline-block;
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 6px 12px;
  color: var(--color-text-secondary);
  text-align: center;
  background: #fff;
  white-space: nowrap;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.2s;
}

.tag-grid .tag:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: rgba(26, 115, 232, 0.05);
}

/* 不同分类颜色 */
.tag-grid .tag[data-category="geo-video"] {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.tag-grid .tag[data-category="geo-methodology"] {
  border-color: var(--color-success);
  color: var(--color-success);
}

.tag-grid .tag[data-category="tools"] {
  border-color: var(--color-warning);
  color: var(--color-warning);
}

.kb-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--spacing-unit) * 1.5);
}
.kb-hd {
  font-weight: 700;
  margin: 0 0 calc(var(--spacing-unit) * 1) 0;
  font-size: 15px;
}

.btn {
  display: inline-block;
  padding: 10px 16px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background: var(--color-primary-light);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(26, 115, 232, 0.3);
}

/* 面包屑导航样式 - 加分隔符图标 */
.breadcrumb {
  padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
  border-bottom: 1px solid #f0f0f0;
  font-size: 13px;
  color: var(--color-text-secondary);
}

.breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: calc(var(--spacing-unit) * 0.5);
}

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

.breadcrumb li:not(:last-child)::after {
  content: "›";
  margin-left: calc(var(--spacing-unit) * 0.5);
  color: #ccc;
  font-size: 14px;
}

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

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

/* 分类描述样式 */
.category-description {
  margin: calc(var(--spacing-unit) * 1) 0 0 0;
  font-size: 14px;
  color: var(--color-text-secondary);
  font-weight: normal;
  line-height: 1.6;
}

/* 文章摘要样式 */
.article-summary {
  color: var(--color-text-secondary);
  line-height: 1.6;
  font-size: 14px;
}

/* 文章元信息样式 */
.article-meta {
  align-items: center;
}

.article-meta time {
  color: var(--color-text-secondary);
}

/* 页脚快速链接 */
.site-footer {
  margin: calc(var(--spacing-unit) * 3) 0 calc(var(--spacing-unit) * 4);
  padding: calc(var(--spacing-unit) * 2);
  color: var(--color-text-secondary);
  font-size: 13px;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: calc(var(--spacing-unit) * 2);
  margin-bottom: calc(var(--spacing-unit) * 1);
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--color-text-secondary);
  font-size: 13px;
}

.footer-links a:hover {
  color: var(--color-primary);
}

@media (max-width: 980px) {
  html, body {
    background: #ffffff;
  }
  .main-wrap {
    grid-template-columns: 1fr;
    gap: calc(var(--spacing-unit) * 1.25);
  }
  .site-header .bar {
    height: auto;
    padding: calc(var(--spacing-unit) * 1.25) 0;
    align-items: flex-start;
    flex-direction: column;
  }
  .nav {
    width: 100%;
    gap: calc(var(--spacing-unit) * 0.75);
  }
  .nav a {
    padding: 6px 10px;
    border-radius: 20px;
    font-size: 13px;
  }
  .container {
    padding: 0 calc(var(--spacing-unit) * 1.25);
  }
  .card {
    border-radius: 12px;
  }
  .card .hd {
    padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 1.5);
    font-size: 15px;
  }
  .card .bd {
    padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 1.5);
  }
  .article-list li {
    padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 1.5);
  }
  .article-title {
    font-size: 16px;
    margin-bottom: calc(var(--spacing-unit) * 0.5);
  }

  .page-title {
    font-size: 20px;
  }
  .meta {
    gap: calc(var(--spacing-unit) * 1);
  }
  .pagination {
    padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 1.5);
  }
  .pagination a, .pagination span {
    padding: 6px 10px;
    border-radius: 8px;
    font-size: 13px;
  }
  .ad {
    padding: calc(var(--spacing-unit) * 1);
    border-radius: 10px;
    margin-bottom: calc(var(--spacing-unit) * 1.25);
  }
  .title-list li {
    padding: calc(var(--spacing-unit) * 0.75) 0;
  }
  .btn {
    padding: 10px 14px;
    border-radius: 8px;
    width: 100%;
    text-align: center;
    box-sizing: border-box;
  }
  .tag-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: calc(var(--spacing-unit) * 0.75);
  }
  .tag-grid .tag {
    padding: 6px 8px;
    font-size: 12px;
  }
  .kb-grid {
    grid-template-columns: 1fr;
  }

  .geo-list {
    grid-template-columns: 1fr;
  }

  .geo-item {
    grid-template-columns: 92px minmax(0, 1fr);
    padding: calc(var(--spacing-unit) * 1);
    border-radius: 10px;
  }

  .geo-item img {
    width: 92px;
    height: 60px;
    border-radius: 8px;
  }
  .kb-hd {
    margin-bottom: calc(var(--spacing-unit) * 0.75);
    font-size: 14px;
  }
  .site-footer {
    margin: calc(var(--spacing-unit) * 2) 0 calc(var(--spacing-unit) * 3);
    padding-bottom: env(safe-area-inset-bottom);
  }
  
  .article-content h2 {
    font-size: 20px;
  }
  
  .article-content h3 {
    font-size: 17px;
  }
}