/* ==========================================================================
   知识科普与 SEO 文章专用排版样式表 (articles.css)
   ========================================================================== */

/* 面包屑导航 */
.breadcrumb-nav {
  padding: 20px 0 10px;
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  font-size: 0.88rem;
  color: var(--text-muted);
}

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

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

.breadcrumb-separator {
  color: var(--text-dim);
}

/* 文章头部区 */
.article-header {
  padding: 32px 0 28px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 36px;
}

.article-category-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  background: rgba(0, 198, 255, 0.12);
  border: 1px solid var(--border-tech);
  color: var(--cyan-primary);
  font-size: 0.82rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.article-page-title {
  font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  font-weight: 800;
  line-height: 1.35;
  color: #FFFFFF;
  margin-bottom: 18px;
}

.article-meta-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* 知识文章主体正文容器 */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 48px;
  padding-bottom: 80px;
}

.article-layout-single {
  grid-template-columns: 1fr;
  max-width: 880px;
  margin: 0 auto;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-body h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-top: 40px;
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-body h2::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 22px;
  background: var(--gradient-tech);
  border-radius: 2px;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #E2E8F0;
  margin-top: 28px;
  margin-bottom: 12px;
}

.article-body p {
  margin-bottom: 20px;
}

.article-body strong {
  color: #FFFFFF;
  font-weight: 700;
}

.article-body a {
  color: var(--cyan-primary);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.article-body a:hover {
  color: #654CFF;
}

.article-body ul, .article-body ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.article-body li {
  margin-bottom: 10px;
}

/* 提示与避坑卡片 (Callout Box) */
.callout-box {
  background: rgba(16, 26, 56, 0.7);
  border-left: 4px solid var(--cyan-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 20px 24px;
  margin: 28px 0;
}

.callout-box.tip {
  border-left-color: var(--cyan-primary);
}

.callout-box.warning {
  border-left-color: #FFB020;
  background: rgba(45, 30, 16, 0.5);
}

.callout-box.note {
  border-left-color: var(--purple-neon);
}

.callout-title {
  font-weight: 700;
  font-size: 1rem;
  color: #FFFFFF;
  margin-bottom: 8px;
}

.callout-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: 0 !important;
}

/* 对比表格 */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 28px 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  text-align: left;
}

.article-table th {
  background: #111A38;
  color: #FFFFFF;
  font-weight: 700;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-tech);
}

.article-table td {
  padding: 12px 18px;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

.article-table tr:hover td {
  background: rgba(0, 198, 255, 0.04);
}

/* 侧边目录 (Sticky TOC) */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.toc-card {
  position: sticky;
  top: calc(var(--header-height) + 24px);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.toc-title {
  font-size: 1rem;
  font-weight: 700;
  color: #FFFFFF;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 0.88rem;
}

.toc-link {
  color: var(--text-muted);
  display: block;
  line-height: 1.4;
}

.toc-link:hover {
  color: var(--cyan-primary);
  transform: translateX(4px);
}

/* 文章底部快捷导航 */
.article-footer-nav {
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.article-footer-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--cyan-primary);
}

.article-footer-link:hover {
  color: #FFFFFF;
}

/* 知识库首页卡片列表 */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  margin-top: 36px;
}

.knowledge-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
}

.knowledge-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-tech);
  box-shadow: 0 12px 30px rgba(0, 198, 255, 0.16);
}

.knowledge-card-tag {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--cyan-primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.knowledge-card-title {
  font-size: 1.22rem;
  font-weight: 700;
  color: #FFFFFF;
  margin-bottom: 12px;
  line-height: 1.4;
}

.knowledge-card-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 24px;
  flex-grow: 1;
}

.knowledge-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.84rem;
  color: var(--text-muted);
}

.knowledge-card-btn {
  font-weight: 600;
  color: var(--cyan-primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

@media (max-width: 900px) {
  .article-layout {
    grid-template-columns: 1fr;
  }
  
  .toc-card {
    display: none;
  }
}