/* ===================================================================
   ImmTelecom (immtelecom.surf) - 知识专栏与文章阅读专用样式表
   深度优化阅读排版 · 纯原生 CSS · 毫秒级秒开
   =================================================================== */

.article-page-header {
  padding: 60px 0 40px;
  background: linear-gradient(180deg, rgba(12, 17, 28, 0.8), transparent);
  border-bottom: 1px solid var(--border-subtle);
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.breadcrumbs a {
  color: var(--text-muted);
}

.breadcrumbs a:hover {
  color: var(--text-accent);
}

.breadcrumbs .sep {
  opacity: 0.5;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 18px;
  flex-wrap: wrap;
  font-size: 0.86rem;
  color: var(--text-muted);
}

.article-category {
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.12);
  padding: 3px 12px;
  border-radius: var(--radius-full);
  font-weight: 600;
}

.article-title-main {
  font-size: clamp(1.8rem, 4vw, 2.7rem);
  font-weight: 800;
  line-height: 1.3;
  color: #ffffff;
  margin-bottom: 20px;
}

.article-lead {
  font-size: 1.12rem;
  color: var(--text-muted);
  line-height: 1.75;
  border-left: 3px solid var(--text-accent);
  padding-left: 18px;
  margin-top: 10px;
}

/* 文章主体布局：双栏 (内容区 + 侧边栏/目录) */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 50px;
  padding: 60px 0;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #cbd5e1;
}

.article-body h2 {
  font-size: 1.65rem;
  font-weight: 700;
  color: #ffffff;
  margin: 44px 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 600;
  color: #e2e8f0;
  margin: 32px 0 14px;
}

.article-body p {
  margin-bottom: 22px;
}

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

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

.article-body strong {
  color: #ffffff;
}

/* 文章内联呼应 / 推荐卡片 */
.article-cta-box {
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.12), rgba(59, 130, 246, 0.18));
  border: 1px solid var(--border-focus);
  border-radius: var(--radius-lg);
  padding: 30px;
  margin: 40px 0;
  text-align: center;
}

.article-cta-box h3 {
  color: #ffffff;
  margin-top: 0;
  margin-bottom: 10px;
}

.article-cta-box p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 20px;
}

/* 提示卡片 Callouts */
.callout {
  padding: 18px 22px;
  border-radius: var(--radius-md);
  margin: 26px 0;
  font-size: 0.96rem;
  line-height: 1.65;
}

.callout-info {
  background: rgba(56, 189, 248, 0.08);
  border-left: 4px solid var(--text-accent);
  color: #bae6fd;
}

.callout-warning {
  background: rgba(245, 158, 11, 0.08);
  border-left: 4px solid #f59e0b;
  color: #fde68a;
}

.callout-success {
  background: rgba(16, 185, 129, 0.08);
  border-left: 4px solid var(--accent-emerald);
  color: #a7f3d0;
}

/* 代码与配置高亮块 */
pre code {
  display: block;
  background: #05070b;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: #38bdf8;
  overflow-x: auto;
  margin: 20px 0;
}

code:not(pre code) {
  background: rgba(255, 255, 255, 0.08);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.88em;
  color: #38bdf8;
}

/* 侧边栏与粘性目录 */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.sidebar-sticky-box {
  position: sticky;
  top: 100px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  backdrop-filter: blur(12px);
}

.toc-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 0.9rem;
}

.toc-list a {
  color: var(--text-muted);
  line-height: 1.45;
}

.toc-list a:hover {
  color: var(--text-accent);
}

/* 侧边栏推广小卡片 */
.sidebar-ad-card {
  background: linear-gradient(135deg, rgba(23, 34, 57, 0.9), rgba(15, 23, 42, 0.95));
  border: 1px solid var(--border-focus);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
}

.sidebar-ad-card h4 {
  color: #ffffff;
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.sidebar-ad-card p {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 18px;
}

/* 文章底部内部跳转：相关文章与上一篇/下一篇 */
.article-footer-nav {
  margin-top: 50px;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.related-articles-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 20px;
}

.related-articles-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.related-article-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: all 0.2s ease;
}

.related-article-item:hover {
  border-color: var(--text-accent);
  background: var(--bg-card-hover);
}

.related-article-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 6px;
  line-height: 1.4;
}

.related-article-date {
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* 响应式断点 */
@media (max-width: 992px) {
  .article-layout {
    grid-template-columns: 1fr;
  }
  
  .sidebar-sticky-box {
    position: relative;
    top: 0;
  }

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