/* ==========================================================================
   阿达西 (Adaxi) 网络加速器 - 核心样式表 (White Background, Blue Gradients & Pattern Prints)
   纯原生 CSS3 | 响应式设计 | 现代极简亮白科技风格 | 背景微纹印花与高感度蓝渐变
   ========================================================================== */

:root {
  --bg-body: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-hover: #ffffff;
  
  --border-color: #e2e8f0;
  --border-hover: #93c5fd;
  --border-glow-blue: rgba(37, 99, 235, 0.35);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-dim: #94a3b8;
  
  --accent-blue: #2563eb;
  --accent-blue-light: #3b82f6;
  --accent-sky: #0284c7;
  --accent-cyan: #06b6d4;
  --accent-indigo: #4f46e5;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #e11d48;
  
  --gradient-brand: linear-gradient(135deg, #1e40af 0%, #2563eb 50%, #0284c7 100%);
  --gradient-text: linear-gradient(135deg, #1d4ed8 0%, #2563eb 50%, #0284c7 100%);
  --gradient-btn-primary: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  --gradient-btn-hover: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  --gradient-card-popular: linear-gradient(180deg, #ffffff 0%, #eff6ff 100%);
  --gradient-hero-bg: radial-gradient(ellipse at 50% 0%, rgba(37, 99, 235, 0.12) 0%, rgba(255, 255, 255, 0) 75%);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-card: 0 10px 30px -10px rgba(37, 99, 235, 0.12);
  --shadow-card-hover: 0 20px 40px -12px rgba(37, 99, 235, 0.22);
  --shadow-btn: 0 6px 20px rgba(37, 99, 235, 0.32);
  
  --transition-fast: 0.2s ease;
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 全局重置与平滑滚动 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

/* 全局背景与微型网格/点阵印花 (Subtle Tech Pattern Prints) */
body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;

  /* 背景科技点阵与十字交叉规则印花 */
  background-image: 
    radial-gradient(rgba(37, 99, 235, 0.12) 1.5px, transparent 1.5px),
    linear-gradient(to right, rgba(37, 99, 235, 0.035) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(37, 99, 235, 0.035) 1px, transparent 1px);
  background-size: 28px 28px, 56px 56px, 56px 56px;
  background-position: 0 0, 0 0, 0 0;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 95px 0;
  position: relative;
}

@media (max-width: 768px) {
  section { padding: 60px 0; }
}

/* 渐变字体与公共辅助类 */
.gradient-text {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.text-center { text-align: center; }

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-full);
  color: var(--accent-blue);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  margin-bottom: 18px;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.08);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 900;
  letter-spacing: -0.8px;
  margin-bottom: 18px;
  color: var(--text-primary);
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 55px auto;
  line-height: 1.7;
}

@media (max-width: 768px) {
  .section-title { font-size: 1.85rem; }
  .section-subtitle { font-size: 0.98rem; margin-bottom: 40px; }
}

/* 现代高感蓝色渐变按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 34px;
  font-size: 1.02rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: var(--transition-normal);
  cursor: pointer;
  border: none;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--gradient-btn-primary);
  color: #ffffff;
  box-shadow: var(--shadow-btn);
}

.btn-primary:hover {
  background: var(--gradient-btn-hover);
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.45);
}

.btn-secondary {
  background: #ffffff;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.btn-secondary:hover {
  background: #f8fafc;
  border-color: var(--border-hover);
  color: var(--accent-blue);
  transform: translateY(-3px);
}

.btn-block { width: 100%; }
.btn-sm { padding: 9px 22px; font-size: 0.88rem; }

/* 头部 Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 18px 0;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-size: 1.4rem;
  font-weight: 900;
  color: var(--text-primary);
}

.brand-icon {
  width: 38px;
  height: 38px;
  background: var(--gradient-btn-primary);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 900;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition-fast);
}

.nav-links a:hover {
  color: var(--accent-blue);
}

@media (max-width: 992px) {
  .nav-links { display: none; }
}

/* 亮白 Hero 主视觉区 (印花与几何暗纹 overlay) */
.hero {
  padding-top: 160px;
  padding-bottom: 100px;
  background: var(--gradient-hero-bg);
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background-image: repeating-linear-gradient(45deg, rgba(37, 99, 235, 0.015) 0, rgba(37, 99, 235, 0.015) 2px, transparent 0, transparent 20px);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
  position: relative;
  z-index: 2;
}

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

.hero-title {
  font-size: 3.4rem;
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -1.2px;
  margin-bottom: 22px;
}

.hero-subtitle {
  font-size: 1.18rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  line-height: 1.75;
}

.hero-cta {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 45px;
}

.hero-features-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding: 20px 24px;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}

.strip-item {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.strip-number {
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--accent-blue);
}

.strip-label {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Hero 右侧动态控制台面板卡片 (Blue HUD Control Center) */
.hero-visual { position: relative; }

.dashboard-card {
  background: #ffffff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: 0 20px 50px -10px rgba(37, 99, 235, 0.18);
  position: relative;
  overflow: hidden;
  animation: floatHUD 6s ease-in-out infinite alternate;
}

@keyframes floatHUD {
  0% { transform: translateY(0px); }
  100% { transform: translateY(-10px); }
}

.dashboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 18px;
  margin-bottom: 22px;
}

.dash-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.status-dot {
  width: 10px;
  height: 10px;
  background-color: var(--accent-emerald);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--accent-emerald);
  animation: pulseDot 2s infinite;
}

@keyframes pulseDot {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.dash-tag {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent-blue);
  background: #eff6ff;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  border: 1px solid #bfdbfe;
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 26px;
}

.node-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.92rem;
  transition: var(--transition-fast);
}

.node-row:hover {
  background: #eff6ff;
  border-color: var(--border-hover);
}

.node-name {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--text-primary);
}

.node-ping {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-emerald);
  font-weight: 800;
  font-family: monospace;
  font-size: 1rem;
}

.speed-meter-box {
  background: #eff6ff;
  border-radius: var(--radius-md);
  padding: 18px;
  border: 1px solid #bfdbfe;
}

.speed-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.speed-value {
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--accent-blue);
  font-family: monospace;
}

.progress-bar-bg {
  width: 100%;
  height: 9px;
  background: #dbeafe;
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 90%;
  background: var(--gradient-btn-primary);
  border-radius: var(--radius-full);
  position: relative;
}

.progress-bar-fill::after {
  content: '';
  position: absolute;
  top: 0; left: 0; bottom: 0; right: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.6), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@media (max-width: 992px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-content { text-align: center; }
  .hero-title { font-size: 2.6rem; }
  .hero-cta { justify-content: center; }
  .hero-features-strip { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .strip-item { align-items: center; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 2rem; }
}

/* 核心优势 3大图文卡片 */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 30px;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.card::after {
  content: '';
  position: absolute;
  top: -40px; right: -40px;
  width: 100px; height: 100px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.card:hover {
  border-color: var(--border-hover);
  transform: translateY(-8px);
  box-shadow: var(--shadow-card-hover);
}

.card-icon-box {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-md);
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 26px;
  color: var(--accent-blue);
}

.card-title {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.card-desc {
  font-size: 0.96rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

@media (max-width: 992px) {
  .advantages-grid { grid-template-columns: 1fr; }
}

/* 流媒体与 AI 解锁图卡板块 */
.media-ai-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.media-ai-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
}

.media-ai-card::before {
  content: '';
  position: absolute;
  bottom: 0; right: 0;
  width: 150px; height: 150px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.04) 0%, transparent 70%);
  pointer-events: none;
}

.media-ai-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 22px;
}

.media-ai-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-streaming { background: #ffe4e6; color: var(--accent-rose); border: 1px solid #fecdd3; }
.icon-ai { background: #f3e8ff; color: var(--accent-indigo); border: 1px solid #e9d5ff; }

.media-ai-title {
  font-size: 1.35rem;
  font-weight: 800;
}

.media-ai-desc {
  font-size: 0.96rem;
  color: var(--text-secondary);
  margin-bottom: 26px;
}

.tags-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-primary);
  transition: var(--transition-fast);
}

.tag-pill:hover {
  background: #eff6ff;
  border-color: var(--border-hover);
  color: var(--accent-blue);
  transform: translateY(-2px);
}

@media (max-width: 992px) {
  .media-ai-container { grid-template-columns: 1fr; }
}

/* 真实价格对比表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 42px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-card);
}

.pricing-card.popular {
  border-color: var(--accent-blue);
  background: var(--gradient-card-popular);
  box-shadow: 0 20px 45px -10px rgba(37, 99, 235, 0.25);
  transform: scale(1.04);
}

.popular-badge {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-btn-primary);
  color: #fff;
  padding: 5px 20px;
  border-radius: var(--radius-full);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.35);
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 26px;
  min-height: 42px;
}

.plan-price {
  margin-bottom: 32px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
}

.price-amount {
  font-size: 3.2rem;
  font-weight: 900;
  line-height: 1;
  color: var(--text-primary);
}

.price-period {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.plan-features {
  list-style: none;
  margin-bottom: 38px;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.94rem;
  color: var(--text-secondary);
  margin-bottom: 15px;
}

.plan-features li.active { color: var(--text-primary); }

.check-icon {
  width: 18px;
  height: 18px;
  color: var(--accent-emerald);
  flex-shrink: 0;
}

@media (max-width: 992px) {
  .pricing-grid { grid-template-columns: 1fr; }
  .pricing-card.popular { transform: none; }
}

/* SEO 文章 9 大图卡板块 (带微格子印花) */
.articles-section {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  position: relative;
}

.articles-section::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background-image: radial-gradient(rgba(37, 99, 235, 0.08) 1.2px, transparent 1.2px);
  background-size: 20px 20px;
  pointer-events: none;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  position: relative;
  z-index: 2;
}

.article-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-card);
}

.article-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-8px);
  box-shadow: var(--shadow-card-hover);
}

.article-card-header {
  padding: 26px 26px 14px 26px;
}

.article-badge {
  display: inline-block;
  padding: 4px 14px;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  color: var(--accent-blue);
  font-size: 0.78rem;
  font-weight: 800;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
}

.article-badge.featured {
  background: #f3e8ff;
  border-color: #e9d5ff;
  color: var(--accent-indigo);
}

.article-card-title {
  font-size: 1.18rem;
  font-weight: 800;
  line-height: 1.45;
  color: var(--text-primary);
  transition: var(--transition-fast);
}

.article-card:hover .article-card-title {
  color: var(--accent-blue);
}

.article-card-body {
  padding: 0 26px 22px 26px;
  flex-grow: 1;
}

.article-excerpt {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.65;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card-footer {
  padding: 18px 26px;
  border-top: 1px solid #f1f5f9;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.84rem;
  color: var(--text-muted);
}

.article-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-blue);
  font-weight: 800;
}

@media (max-width: 992px) {
  .articles-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .articles-grid { grid-template-columns: 1fr; }
}

/* 用户评价区 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-card);
}

.review-stars {
  color: var(--accent-amber);
  margin-bottom: 18px;
  display: flex;
  gap: 4px;
  font-size: 1.1rem;
}

.review-text {
  font-size: 0.96rem;
  color: var(--text-primary);
  line-height: 1.65;
  margin-bottom: 26px;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 14px;
}

.avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--gradient-btn-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #fff;
  font-size: 1.05rem;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.author-info .author-name { font-size: 0.98rem; font-weight: 800; }
.author-info .author-role { font-size: 0.84rem; color: var(--text-secondary); }

@media (max-width: 992px) {
  .reviews-grid { grid-template-columns: 1fr; }
}

/* FAQ 常见问题 (原生 CSS Accordion) */
.faq-list {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.faq-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition-fast);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
}

.faq-item[open] {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-card);
}

.faq-summary {
  padding: 22px 28px;
  font-size: 1.08rem;
  font-weight: 800;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.faq-summary::-webkit-details-marker { display: none; }

.faq-icon {
  width: 22px;
  height: 22px;
  color: var(--accent-blue);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item[open] .faq-icon { transform: rotate(180deg); }

.faq-content {
  padding: 0 28px 26px 28px;
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.75;
  border-top: 1px solid #f1f5f9;
  padding-top: 18px;
}

/* 精简页脚 Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 55px 0;
  margin-top: 40px;
  position: relative;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.footer-nav a {
  color: var(--text-primary);
  text-decoration: none;
  font-size: 1.05rem;
  font-weight: 800;
  transition: var(--transition-fast);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
}

.footer-nav a:hover {
  color: var(--accent-blue);
  background: #eff6ff;
}

.footer-pbn-links a {
  color: var(--accent-blue) !important;
}

.footer-pbn-links a:hover {
  color: var(--accent-indigo) !important;
  text-decoration: underline !important;
}

.footer-copyright {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* 子页面及 SEO 文章详情页 通用样式 (Light Theme with Prints) */
.page-header {
  padding-top: 150px;
  padding-bottom: 45px;
  background: var(--gradient-hero-bg);
  border-bottom: 1px solid var(--border-color);
}

.content-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 45px;
  margin: 45px 0 85px 0;
  color: var(--text-secondary);
  line-height: 1.85;
  box-shadow: var(--shadow-card);
}

.content-box h2 {
  color: var(--text-primary);
  font-size: 1.55rem;
  margin: 32px 0 18px 0;
}

.content-box h2:first-child { margin-top: 0; }
.content-box p { margin-bottom: 18px; }
.content-box ul { margin-bottom: 22px; padding-left: 22px; }
.content-box li { margin-bottom: 10px; }

.info-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
  margin: 26px 0;
}

.info-item {
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 22px;
}

.info-item h3 {
  color: var(--text-primary);
  font-size: 1.12rem;
  margin-bottom: 10px;
}

/* 单篇 SEO 文章详情页页面样式 (Light Mode) */
.article-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 40px 20px 80px 20px;
}

.article-header {
  margin-bottom: 40px;
  text-align: left;
}

.article-main-title {
  font-size: 2.3rem;
  font-weight: 900;
  line-height: 1.25;
  margin: 16px 0;
  color: var(--text-primary);
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 20px;
}

.article-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 44px;
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.85;
  box-shadow: var(--shadow-card);
}

.article-content h2 {
  color: var(--text-primary);
  font-size: 1.55rem;
  font-weight: 800;
  margin: 36px 0 18px 0;
  border-left: 4px solid var(--accent-blue);
  padding-left: 14px;
}

.article-content h3 {
  color: var(--text-primary);
  font-size: 1.25rem;
  font-weight: 700;
  margin: 24px 0 14px 0;
}

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

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

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

.article-content a {
  color: var(--accent-blue);
  text-decoration: underline;
  text-underline-offset: 4px;
  font-weight: 700;
}

.article-content a:hover {
  color: var(--accent-indigo);
}

.article-cta-box {
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-md);
  padding: 32px;
  text-align: center;
  margin: 40px 0 20px 0;
}

.article-cta-box h3 {
  color: var(--text-primary);
  font-size: 1.35rem;
  margin: 0 0 10px 0;
}

@media (max-width: 768px) {
  .content-box { padding: 26px; }
  .article-content { padding: 24px; font-size: 0.98rem; }
  .article-main-title { font-size: 1.75rem; }
  .info-grid { grid-template-columns: 1fr; }
  .footer-nav { gap: 20px; }
}