/* BestTelecom.cyou - 鲜明深蓝背景 + 黑曜石暗黑卡片 (Obsidian Black Cards on Vivid Navy) 调优样式表 */
:root {
  --bg-primary: #0a192f;          /* 鲜明深海夜幕蓝 (Vivid Deep Navy Background) */
  --bg-secondary: #040c1a;        /* 深沉黑曜石底色 */
  --bg-card: #030712;             /* 高纯度黑曜石暗黑面板 (Obsidian Black) */
  --bg-card-hover: #0a1426;       /* 悬浮微光炭黑 */
  --bg-card-glass: rgba(3, 7, 18, 0.94);
  --border-color: rgba(96, 165, 250, 0.32); /* 电光冰蓝边框 */
  --border-focus: #60a5fa;
  --accent-cyan: #60a5fa;         /* 鲜亮天空蓝 */
  --accent-blue: #3b82f6;         /* 鲜艳皇家蓝 */
  --accent-light-blue: #93c5fd;   /* 极光冰蓝高光 */
  --accent-blue-glow: rgba(59, 130, 246, 0.45);
  --accent-green: #10b981;        /* 专线通畅绿 */
  --text-main: #ffffff;           /* 极清纯白 */
  --text-muted: #bfdbfe;          /* 高对比柔和浅蓝 */
  --text-dim: #93c5fd;            /* 冰蓝说明文字 */
  --gradient-brand: linear-gradient(135deg, #93c5fd 0%, #60a5fa 45%, #3b82f6 100%);
  --gradient-btn: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  --gradient-card-popular: linear-gradient(180deg, rgba(59, 130, 246, 0.3) 0%, #030712 100%);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --container-max: 1240px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --shadow-card: 0 18px 45px -10px rgba(0, 0, 0, 0.95);
  --shadow-glow: 0 0 36px rgba(59, 130, 246, 0.4);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  background-color: var(--bg-primary);
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(59, 130, 246, 0.35) 0%, transparent 60%),
    radial-gradient(circle at 85% 25%, rgba(96, 165, 250, 0.25) 0%, transparent 45%),
    radial-gradient(circle at 10% 65%, rgba(147, 197, 253, 0.2) 0%, transparent 50%),
    radial-gradient(circle at 50% 100%, rgba(59, 130, 246, 0.28) 0%, transparent 60%),
    linear-gradient(rgba(96, 165, 250, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(96, 165, 250, 0.07) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 100% 100%, 100% 100%, 54px 54px, 54px 54px;
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.text-gradient {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--gradient-btn);
  color: #ffffff;
  font-weight: 700;
  padding: 14px 32px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(147, 197, 253, 0.45);
  cursor: pointer;
  box-shadow: 0 4px 24px var(--accent-blue-glow);
  transition: var(--transition);
  text-align: center;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(96, 165, 250, 0.6);
  background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
  color: #ffffff;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(3, 7, 18, 0.6);
  color: var(--text-main);
  font-weight: 600;
  padding: 14px 32px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.btn-secondary:hover {
  background: rgba(96, 165, 250, 0.18);
  border-color: var(--accent-cyan);
  color: #ffffff;
  transform: translateY(-2px);
}

/* 顶部导航 (黑曜石玻璃) */
.header-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(3, 7, 18, 0.94);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(96, 165, 250, 0.28);
  transition: var(--transition);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.5px;
}

.logo-img {
  width: 40px;
  height: 40px;
}

.logo-badge {
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 20px;
  background: rgba(96, 165, 250, 0.18);
  color: var(--accent-cyan);
  border: 1px solid rgba(96, 165, 250, 0.4);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 600;
  transition: var(--transition);
}

.nav-links a:hover, .nav-links a.active {
  color: var(--accent-cyan);
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  font-size: 1.4rem;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.mobile-nav-drawer {
  display: none;
  background: #030712;
  border-bottom: 1px solid var(--border-color);
  padding: 24px;
}

.mobile-nav-drawer.open {
  display: block;
}

.mobile-nav-links {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.mobile-nav-links a {
  color: var(--text-muted);
  font-size: 1.05rem;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

/* Hero 双栏 */
.hero-section {
  padding: 90px 0 70px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-left {
  text-align: left;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 22px;
  background: rgba(3, 7, 18, 0.7);
  border: 1px solid rgba(96, 165, 250, 0.45);
  border-radius: 40px;
  font-size: 0.9rem;
  color: var(--accent-light-blue);
  margin-bottom: 24px;
  box-shadow: 0 0 24px rgba(59, 130, 246, 0.25);
  font-weight: 600;
}

.hero-title {
  font-size: 3.3rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 22px;
  letter-spacing: -1px;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 36px;
  line-height: 1.75;
}

.hero-subtitle strong {
  color: var(--accent-light-blue);
  font-weight: 700;
}

.hero-cta-group {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 44px;
}

/* Hero 右侧 Live Console 黑曜石卡片 */
.hero-console-widget {
  background: #030712;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-card), var(--shadow-glow);
  position: relative;
}

.console-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 16px;
  margin-bottom: 20px;
}

.console-title {
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-main);
}

.status-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 14px var(--accent-green);
}

.console-status-tag {
  background: rgba(16, 185, 129, 0.18);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.4);
  font-size: 0.78rem;
  padding: 3px 10px;
  border-radius: 20px;
  font-weight: 600;
}

.console-metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-bottom: 20px;
}

.console-metric-box {
  background: #081124;
  border: 1px solid rgba(96, 165, 250, 0.25);
  padding: 16px;
  border-radius: var(--radius-sm);
}

.console-metric-val {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--accent-cyan);
  margin-bottom: 2px;
}

.console-metric-lbl {
  font-size: 0.8rem;
  color: var(--text-dim);
}

.console-speed-bar {
  background: #081124;
  border: 1px solid rgba(96, 165, 250, 0.25);
  border-radius: var(--radius-sm);
  padding: 16px;
}

.speed-bar-top {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.speed-track {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  overflow: hidden;
}

.speed-fill {
  height: 100%;
  width: 96%;
  background: var(--gradient-brand);
  border-radius: 4px;
  box-shadow: 0 0 12px var(--accent-cyan);
}

.section-padding {
  padding: 90px 0;
}

.section-header {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 50px;
}

.section-tag {
  display: inline-block;
  color: var(--accent-cyan);
  font-size: 0.88rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 12px;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 18px;
  line-height: 1.3;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--text-muted);
}

/* Tab 切换黑曜石容器 */
.tab-switcher-wrapper {
  background: #040c1a;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow-card);
}

.tab-navigation {
  display: flex;
  justify-content: center;
  gap: 14px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.tab-btn {
  background: #081124;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 700;
  padding: 12px 28px;
  border-radius: 30px;
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn:hover {
  background: rgba(96, 165, 250, 0.15);
  color: #ffffff;
}

.tab-btn.active {
  background: var(--gradient-btn);
  color: #ffffff;
  border-color: rgba(147, 197, 253, 0.5);
  box-shadow: 0 4px 18px var(--accent-blue-glow);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.tab-feature-card {
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 30px;
  transition: var(--transition);
}

.tab-feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-glow);
  background: #081124;
}

.tab-feature-icon {
  font-size: 2.6rem;
  margin-bottom: 16px;
}

.tab-feature-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.tab-feature-card p {
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.7;
}

.tab-feature-card strong {
  color: var(--accent-light-blue);
}

/* 价格卡片黑曜石矩阵 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.pricing-card {
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  position: relative;
}

.pricing-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-card);
  background: #081124;
}

.pricing-card.popular {
  border: 2px solid var(--accent-cyan);
  background: var(--gradient-card-popular);
  box-shadow: 0 14px 45px -10px rgba(59, 130, 246, 0.5);
}

.popular-tag {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-brand);
  color: #030712;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 5px 16px;
  border-radius: 20px;
  white-space: nowrap;
  box-shadow: 0 4px 14px rgba(96, 165, 250, 0.45);
}

.plan-title {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--text-main);
}

.plan-subtitle {
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-bottom: 22px;
  min-height: 42px;
}

.plan-price-box {
  margin-bottom: 26px;
  padding-bottom: 22px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.plan-price {
  font-size: 2.5rem;
  font-weight: 800;
  color: #ffffff;
}

.plan-price span {
  font-size: 0.95rem;
  font-weight: normal;
  color: var(--text-muted);
}

.plan-features {
  margin-bottom: 30px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.plan-features li {
  font-size: 0.92rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 10px;
}

.plan-features svg {
  width: 18px;
  height: 18px;
  color: var(--accent-cyan);
  flex-shrink: 0;
}

/* 客户端支持黑曜石卡片 */
.client-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 18px;
}

.client-card {
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px 18px;
  text-align: center;
  transition: var(--transition);
}

.client-card:hover {
  border-color: var(--accent-cyan);
  transform: translateY(-4px);
  background: #081124;
}

.client-icon {
  font-size: 2.5rem;
  margin-bottom: 14px;
}

.client-name {
  font-weight: 700;
  margin-bottom: 6px;
}

.client-apps {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* 真实用户的 口碑评价与推荐 (黑曜石卡片) */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.testimonial-card {
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.testimonial-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-glow);
  background: #081124;
}

.testimonial-stars {
  color: #fbbf24;
  margin-bottom: 16px;
  font-size: 1.05rem;
  letter-spacing: 3px;
}

.testimonial-text {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 24px;
}

.testimonial-user {
  display: flex;
  align-items: center;
  gap: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 18px;
}

.user-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #030712;
  font-size: 1.2rem;
}

.user-name {
  font-weight: 700;
  font-size: 1rem;
}

.user-role {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* FAQ 手风琴黑曜石卡片 */
.faq-list {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.faq-item {
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-question {
  width: 100%;
  padding: 24px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  text-align: left;
}

.faq-question:hover {
  color: var(--accent-cyan);
}

.faq-toggle-icon {
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--text-muted);
  transition: transform 0.3s ease;
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(45deg);
  color: var(--accent-cyan);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 28px;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.75;
}

.faq-item.active .faq-answer {
  max-height: 380px;
  padding: 0 28px 24px;
}

/* 博客文章黑曜石矩阵 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.article-card {
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.article-card:hover {
  border-color: var(--accent-cyan);
  transform: translateY(-5px);
  box-shadow: var(--shadow-card);
  background: #081124;
}

.article-badge {
  display: inline-block;
  font-size: 0.78rem;
  padding: 4px 12px;
  border-radius: 6px;
  background: rgba(96, 165, 250, 0.15);
  color: var(--accent-cyan);
  margin-bottom: 16px;
  font-weight: 700;
}

.article-card h3 {
  font-size: 1.2rem;
  margin-bottom: 14px;
  line-height: 1.5;
}

.article-card h3 a {
  color: var(--text-main);
  transition: var(--transition);
}

.article-card h3 a:hover {
  color: var(--accent-cyan);
}

.article-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 22px;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-dim);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 16px;
}

/* 页脚与 PBN 友情链接区 (核心任务 2 专用规范) */
.site-footer {
  background: #02050c;
  border-top: 1px solid rgba(96, 165, 250, 0.25);
  padding: 65px 0 40px;
  text-align: center;
}

.footer-content {
  max-width: 860px;
  margin: 0 auto;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 18px;
}

.footer-desc {
  font-size: 0.95rem;
  color: var(--text-dim);
  line-height: 1.75;
  margin-bottom: 26px;
}

.footer-nav {
  display: flex;
  justify-content: center;
  gap: 26px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.footer-nav a {
  color: var(--text-muted);
  font-size: 0.92rem;
  transition: var(--transition);
}

.footer-nav a:hover {
  color: var(--accent-cyan);
}

.footer-copyright {
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-bottom: 24px;
}

.pbn-links-area {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 12px 28px;
  border-radius: 40px;
  background: rgba(3, 7, 18, 0.8);
  border: 1px solid rgba(96, 165, 250, 0.25);
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-top: 10px;
}

.pbn-links-title {
  color: var(--text-dim);
  font-size: 0.82rem;
}

.pbn-link-item {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.82rem;
  transition: color 0.2s ease;
}

.pbn-link-item:hover {
  color: var(--accent-cyan);
  text-decoration: underline;
}

/* 文章双栏侧边栏目录阅读排版 */
.reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  background: var(--gradient-brand);
  width: 0%;
  z-index: 1001;
  transition: width 0.1s ease;
}

.article-layout-grid {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 40px;
  max-width: 1200px;
  margin: 40px auto 90px;
  padding: 0 24px;
}

.toc-sidebar {
  position: relative;
}

.toc-sticky {
  position: sticky;
  top: 100px;
  background: #030712;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  box-shadow: var(--shadow-card);
}

.toc-title {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--accent-cyan);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.toc-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 0.88rem;
}

.toc-list a {
  color: var(--text-muted);
  transition: var(--transition);
  display: block;
  line-height: 1.4;
  padding: 4px 8px;
  border-radius: 6px;
}

.toc-list a:hover, .toc-list a.active {
  color: var(--accent-light-blue);
  background: rgba(96, 165, 250, 0.15);
  font-weight: 700;
}

.article-main-content {
  min-width: 0;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-bottom: 24px;
}

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

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

.article-header {
  margin-bottom: 36px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 26px;
}

.article-header .article-category {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-cyan);
  background: rgba(96, 165, 250, 0.15);
  padding: 5px 14px;
  border-radius: 20px;
  margin-bottom: 16px;
}

.article-header .article-title {
  font-size: 2.3rem;
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 20px;
  color: #ffffff;
}

.article-header .article-meta-info {
  display: flex;
  gap: 22px;
  font-size: 0.88rem;
  color: var(--text-dim);
  flex-wrap: wrap;
}

.article-body {
  color: #e0f2fe;
  font-size: 1.08rem;
  line-height: 1.88;
}

.article-body p {
  margin-bottom: 24px;
}

.article-body h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: #ffffff;
  margin: 44px 0 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #f1f5f9;
  margin: 30px 0 16px;
}

.article-body ul, .article-body ol {
  margin: 0 0 26px 22px;
}

.article-body ul {
  list-style: disc;
}

.article-body ol {
  list-style: decimal;
}

.article-body li {
  margin-bottom: 12px;
  line-height: 1.8;
}

.article-body strong {
  color: var(--accent-cyan);
}

.article-body blockquote {
  background: rgba(3, 7, 18, 0.8);
  border-left: 4px solid var(--accent-cyan);
  padding: 20px 24px;
  margin: 28px 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-muted);
  font-style: italic;
}

.article-cta-box {
  background: linear-gradient(135deg, #030712 0%, #081124 100%);
  border: 1px solid var(--accent-cyan);
  box-shadow: var(--shadow-glow);
  border-radius: var(--radius-md);
  padding: 38px 32px;
  text-align: center;
  margin: 44px 0;
}

.article-cta-box h3 {
  font-size: 1.5rem;
  color: #ffffff;
  margin-bottom: 14px;
}

.article-cta-box p {
  color: var(--text-muted);
  font-size: 1rem;
  max-width: 650px;
  margin: 0 auto 22px;
}

.article-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 50px;
  padding-top: 26px;
  border-top: 1px solid var(--border-color);
  gap: 18px;
  flex-wrap: wrap;
}

.article-nav a {
  color: var(--accent-cyan);
  font-size: 0.98rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.article-nav a:hover {
  text-decoration: underline;
}

/* 响应式断点适配 */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .tab-content.active, .articles-grid, .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .client-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .hero-title {
    font-size: 2.8rem;
  }
  .article-layout-grid {
    grid-template-columns: 1fr;
  }
  .toc-sidebar {
    display: none;
  }
}

@media (max-width: 768px) {
  .nav-links, .nav-cta-btn {
    display: none;
  }
  .mobile-menu-toggle {
    display: block;
  }
  .hero-section {
    padding: 60px 0 40px;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .hero-subtitle {
    font-size: 1.02rem;
  }
  .tab-content.active, .articles-grid, .testimonials-grid, .pricing-grid {
    grid-template-columns: 1fr;
  }
  .client-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .section-title {
    font-size: 1.9rem;
  }
  .article-header .article-title {
    font-size: 1.75rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.9rem;
  }
  .client-grid {
    grid-template-columns: 1fr;
  }
  .pbn-links-area {
    flex-direction: column;
    gap: 8px;
    padding: 12px 20px;
  }
}